TOPODRONE 100/100+/200+


Disclaimer

TOPODRONE LiDAR 100/100+/200+ - are high-accuarate surveying measuring instruments that require careful and precise handling to ensure a long service life.

Do not use the TOPODRONE LiDAR in any way not described in this manual or the user's guide.

Do not subject TOPODRONE LiDAR to shock or vibration, especially when the unit is turned on.

Do not place TOPODRONE LiDAR in direct sunlight, in places with poor ventilation, or near a source of heat or cold.

Do not fully or partially submerge the laser scanner in water or expose the product to heavy rain, snow, sand, or dust for extended periods of time.

Do not insert foreign objects into the memory card, LEMO 6-Pin and external GNSS antenna slots, or install the memory card upside down or attempt to connect incompatible slots.

Do not insert or remove the MicroSD card while the TOPODRONE LiDAR is operating, as this may cause the card to malfunction and/or data loss.

Safe storage of TOPODRONE LiDAR.

When the TOPODRONE LiDAR is not in use, it is recommended to store the device in a room with a relative humidity of 40% or less and a temperature of 20±5°C.

If the TOPODRONE LiDAR gets wet from rain, snow or fog during operation, wipe it with a clean, dry paper or microfiber cloth. Then leave it in a dry room for an hour to dry completely.

Technological requirements

TOPODRONE LiDAR operate using PPK technology and require GNSS data for the duration of their operation from the base station for data post-processing.

To obtain correct data from TOPODRONE LiDAR it is necessary to have a quality GNSS signal during operation, both for the geodetic receiver and for the base station.

The manufacturer does not guarantee the performance of TOPODRONE LiDAR in case of intentional or accidental violation of any of the requirements described above.

TOPODRONE LiDAR design and overview

TOPODRONE LiDAR 100/100+/200+ is a multifunctional device designed for airborne and mobile laser scanning (ALS and MLS) of the earth's surface. The main task of the TOPODRONE LiDAR is to acquire data to generate a dense cloud of terrain points, which in turn allows the classification and processing of this data. The obtained data can be used for various tasks such as geodesy, cartography, volume measurement, taxation and monitoring of various objects.

TOPODRONE LiDAR can operate in a variety of environments, including dense grass, forest or urban areas, under all lighting conditions. However, for effective operation of TOPODRONE LiDAR it is necessary to have sufficient Global Navigation Satellite Systems (GNSS) signal. The use of SLAM technology in the post-processing software TOPODRONE Post Processing allows you to get highly accurate data even in the presence of a weak GNSS signal on the main trajectory.

In the process, to obtain optimal results, the laser scanner should cover certain areas of the ground surface with at least 30% overlap (106 degrees under the UAV in VLS, and 360 degrees around in MLS).
Subsequently, the data from the laser scanner are processed sequentially in several software to equalize the data, align the scans, filter out noise, classify the point cloud, and produce the final materials:1
1. TOPODRONE Post Processing, which calculates a high-precision laser scanner trajectory, generates a dense raw point cloud and initially aligns the scans to each other (Strip Alignment).
2. LiDAR360 software, which performs high-precision alignment of scans to each other (Strip Alignment) and applies several filters to reduce noise and improve the accuracy of the final point cloud. LiDAR360 software can then classify the point cloud and generate final materials (DEM, DEM, etc.).
Further post-processing of data from TOPODRONE LiDAR is performed in the software that is necessary to fulfill the final tasks for a particular user.

Application of SLAM technology in TOPODRONE Post Processing software allows you to get highly accurate data even in the presence of weak GNSS signal on the main trajectory.

TOPODRONE PPK GNSS receiver integrated into TOPODRONE LiDAR, together with high-precision inertial measurement unit (IMU) allows to obtain high-precision coordinates of the TOPODRONE LiDAR trajectory after post-processing, as well as high-precision coordinates of photo centers from TOPODRONE P24 / P61 cameras, synchronizing both devices by cable. GNSS receiver records “raw” GNSS measurements in *.UBX format and time stamps of the TOPODRONE P24 / P61 camera shutter, if it is connected.

Operation of TOPODRONE LiDAR without GNSS signal is not possible.

TOPODRONE LiDAR 100 / 100+ / 200+ is based on the following modules and systems: 

  1. LiDAR sensor housing;

  2. Sensor lens;

  3. Operation status LED;

  4. TOPODRONE LiDAR housing;

  5. Mounting holes with M3 thread;

  6. High precision inertial measurement unit (IMU);

  7. LEMO FFA.00 connector for external GNSS antenna cable connection;

  8. USB Type-C 2.0 connector;

  9. Mounting holes with M3 thread;

  10. LEMO 6 pin connector;

  11. Micro-SD memory card slot;

  12. GNSS receiver TOPODRONE.

Description of TOPODRONE LiDAR 100 / 100+ / 200+ components:

1. LiDAR Hesai sensor housing. Made of aluminium alloy, coated with grey enamel. During operation, the housing may slightly vibrate and make sounds and may heat up to 60°C. This effect is caused by the rotation of the scanning units of the laser heads inside the case, as well as heat dissipation from the working internal components.

2. LiDAR Hesai sensor lens. It is made of glass with polymer anti-reflective coating. It acts as a filter that transmits light only in the working wavelengths of the laser, as well as mechanical protection of the scanning rotating laser heads of the sensor. The coating of the laser scanning sensor lens is vulnerable to scratching and chipping. It is strongly recommended that the TOPODRONE LiDAR lens be treated with care and not be operated under conditions that could damage or scratch the surface of the laser scanning sensor. If scratches and damage occur, the quality of the acquired data may deteriorate. Individual single minor scratches do not generally reduce the quality of the data.

3. TOPODRONE LiDAR status LED. Displays the current operating status of the device. Below is the decoding of the light signals:

Switching on and off

1

 Infrequent green flashes Charging Ionistors
Normal ~10 seconds

2

Flashing green

Linux booting
Normal ~20 seconds

3

Flashing red, siren

After 1 minute of flashing green
Linux failed to boot
Problem with image or flash drive

4

Green

Linux booted, waiting for services

Normal ~10 seconds

5

Rapid flashing green

After power off, shutdown.

Normal ~10 seconds

Waiting for and recording data

6

Green

 System initialisation

7

Siren, flashing red

Hardware problem with Ublox or IMU

8

Green flashing orange

Waiting for GNSS signal

The better the signal, the faster the flicker

9

Green

Time setting

Normally ~ 1 c

10

 Green flashing blue

Start recording

Normally ~ 10 s

11

Triple signal, blue

Recording

Copying data (after connecting a USB stick)

12

Green

 Recording stopped
Normal ~ 1 c

13

Flashing crimson, rising tone signal

Start copying

14

One flash red, siren

Error mounting the USB stick

Faulty USB stick or file system

15

Two flashes red, siren

Not enough space on the USB stick

16

Flashing crimson

Copying data

Flickering speeds up during copying process

17

Fast flashing red, siren

Write error

18

Green, decreasing tone signal

All data copied

4. TOPODRONE LiDAR housing. Made of aluminium alloy for better heat transfer and weight reduction. It is the main supporting structure of the LiDAR.

5. M3 fixing holes are made inside the aluminium body of TOPODRONE LiDAR for attaching it to a backpack or car mount.

6. The IMU (Inertial Measurement Unit), a high-precision inertial measurement unit, is used to record lateral and radial accelerations and inclination angles of the LiDAR during ALS and MLS operations. The data from the IMU is required for use in the post-processing phase for flight path equalisation. Antenna offsets are calculated from the centre of the IMU to the phase centre of the external GNSS antenna. Honeywell and Epson IMUs are used.

7. LEMO FFA.00 connector for connecting an external GNSS antenna. It is used for ALS and MLS. When performing ALS, it is necessary to connect the Helix cable of the antenna installed on the drone. When performing MLS it is necessary to connect the antenna cable from the GNSS antenna TOPODRONE BackPack.

8. USB Type-C Gen.3.2 connector is used to transfer data recorded in TOPODRONE LiDAR to an external storage device, as well as to connect to a mobile device via USB-OTG adapter to change the laser scanning angles and output the LiDAR Hesai sensor to the Internet when contacting the technical support service. Never connect external power to the USB Type-C connector.

9. M3 fixing holes for LiDAR attachment to the aircraft. The TOPODRONE quick-release mount is installed in these mounting holes.

10. LEMO 6-Pin connector to connect external power from a drone, backpack or mobile vehicle mount and get timestamps of the camera shutter.

11. Micro-SD memory card slot for data recording. If there is a memory card in this slot, formatted in NTFS format and there is enough free space on it, data is written directly to this memory card. If no memory card is installed, data is written to the internal flash memory. In this case, you will need to upload the data to an external storage device via the USB Type-C Gen.3.2 connector in the future

12. The TOPODRONE GNSS receiver is based on the uBlox chip. The data recording, storage and transmission system is based on a high-speed flash memory module with 256 GB capacity. The power system of TOPODRONE LiDAR is based on ionisers, which provide power to the electronic component to end the recording when the power supply is interrupted at the end of work.

Supply package

 

1 TOPODRONE LiDAR
2 Protective cover for the laser scanner lens
3 Quick-release dovetail mount - or mount the laser scanner to the UAV in the DJI SkyPort payload slot with protective cover - optional
4 Spare antenna cable with connectors
5 GNSS antenna mount with cable and mounting screws
6 External GNSS antenna
7 MicroSD card at least 32 GB
8 External USB Type-C flash drive not less than 32 GB
9 OTG USB Type-C to USB Type-A adapter 
10 Cloth for wiping the lens
11 Power supply 220V (USB Type-C) for power supply (PD 12-15-20V)
12 USB-Type-C to LEMO 6-PIN power cable for power supply power supply
13 M3x8 screws for attaching TOPODRONE LiDAR to the mount with DJI SkyPort connector
14 Protective carrying case with a lodgement for transportation

Requirements and operating conditions

TOPODRONE LiDAR are designed for use in weather without precipitation. Operation in rain, snow, frost, hail and fog is prohibited. The construction of TOPODRONE LiDAR does not have protection according to IP standard and in case of violation of this recommendation, moisture can get on the surface of the scanning lens and inside the device. This, in its turn, may deteriorate the quality of the received data, as well as damage the internal structure of the laser scanner itself. If precipitation begins, we recommend that you stop using the equipment. If scanning is performed in the presence of even slight rain, additional noise from false reflections due to water droplets or snow may occur.

Noises from false reflections of the TOPODRONE LiDAR, ALS was conducted during rain.

Operation of the TOPODRONE LiDAR in sub-zero temperatures and high humidity (above 80%) can lead to icing of the equipment and the drone. This can deteriorate the quality of the acquired data, as well as cause damage to the laser scanner structure and even lead to the aircraft crashing during ALS due to icing of the carrying propellers and their probable firing as a result of a sharp increase in the mass of the carrying blades.
DJI M200 and TOPODRONE LIDAR icing  DJI M200 blades and icing 

When operating TOPODRONE ALS laser scanners in winds above 7 m/s, it is necessary to increase the side overlap of the drone between scans, as the wind can affect the number of overlapping areas. Operation of TOPODRONE LiDAR for MLS in strong winds is limited by the physical capabilities of the operator. The maximum recommended wind strength when performing ALS is 10 m/s. High winds have a much lower impact on data quality degradation when performing MLS than when performing ALS. It is not recommended to perform terrain surface scanning immediately after rain or wet snow, when there is still a thin film of water on the surface due to much worse reflection and, as a consequence, less number of points received from the surface.

For correct data post-processing it is necessary to perform at least two passes in forward and reverse directions with overlap of at least 30% relative to each other. A single pass is not effective. In case of insufficient quality or complete absence of GNSS signal, operation of TOPODRONE 100/100+/200+ laser scanners is impossible. The minimum visible number of satellites is 8 (above the elevation mask of 15°). It is strongly recommended to check the weather conditions and the number of visible GNSS satellites before the flight. It does not always make sense to perform ALS / MLS in the same area at different times.

Operation of the TOPODRONE LiDAR requires careful and gentle handling of the main lens of the laser scanning sensor. This lens has a surface hardness similar to plastic, not glass. Due to this fact, foreign objects can easily scratch the surface of the sensor. Minor single scratches on the sensor will not result in a noticeable deterioration of the data quality. To protect the lens surface from scratches, it is recommended to use a cover. It is not recommended to keep the TOPODRONE LiDAR switched on for more than 4 hours.

The manufacturer is not responsible for equipment malfunction or for obtaining poor or inaccurate data when used outside the recommended operating conditions.

Technical specifications

  200+ 100+ 100
Sensor Type:  XT32M2X XT32 XT16
Laser Sensor Drive Type: Mechanical circular rotation Mechanical circular rotation Mechanical circular rotation
Max. range of beam (m): 300 120 120
XYZ accuracy (cm): 3-5 3-5 3-5
Max. sensor rpm: 1200 1200 1200
Recommended rsensor pm: 600 600 600
Number of laser beams (pcs):  32 32 16
MLS all-round viewing angle: 0-360 0-360 0-360
ALS Angle of circular view: 217-323 217-323 217-323
Vertical viewing angle: 40.3(+19.5…-20.8) 31(+15…-16) 30(+15…-15)
Horizontal resolution, °: 0.09 0.09 0.09
Vertical resolution, °: 1.3 1 2
Weight (g):  800 1000 1000
Dimensions (WxDxH) (mm): 118х155х105 120х155х105 120х155х105
Laser operating wavelength (nm): 905nm 905nm  905nm 
Reflection type: Triple Return Dual Return Dual Return
Number of points at single reflection 640000 640000 320000
Number of dots for double reflection 1280000 1280000 640000
Number of dots at triple reflection 1920000 - -
Laser Safety Class:  Class 1 safe for eyes Class 1 safe for eyes Class 1 safe for eyes
Power consumption (watt.): 10 10 9
Operating voltage, V 12–28 12–28 12–28
Connectors for power supply: LEMO 4 PIN, USB-Type-C LEMO 4 PIN, USB-Type-C LEMO 4 PIN, USB-Type-C
Antenna connector: LEMO FFA.00 LEMO FFA.00 LEMO FFA.00
Min. number of visible satellites to pass initialisation: 8 8 8
Max. ALS wind strength (m/s): 10 10 10
Operating temperature range: -20°C ... +60°C -20°C ... +60°C -20°C ... +60°C
Storage temperature range: -40°C ... +60°C -40°C ... +60°C -40°C ... +60°C
Operating humidity range: 20% ... 95% 20% ... 95% 20% ... 95%
IMU operating frequency (Hz): 200 200 200
Recommended operating altitude (m): 70-150 90-110 90-110
Supported GNSS systems and frequencies:

GPS: L1C/A, L2C;

GLONASS: L1OF, L2OF;

GALILEO: E1B/C, E5b;

BEIDOU: B1I, B2I

GPS: L1C/A, L2C;

GLONASS: L1OF, L2OF;

GALILEO: E1B/C, E5b;

BEIDOU: B1I, B2I

GPS: L1C/A, L2C;

GLONASS: L1OF, L2OF;

GALILEO: E1B/C, E5b;

BEIDOU: B1I, B2I
Number of GNSS receiver channels: 184 184 184
Raw measurement recording frequency, Hertz: 10 10 10
Yaw axis accuracy (°, 1σ): 0.08 0.08 0.08
Pitch axis accuracy (°, 1σ): 0.03 0.03 0.03
Roll axis accuracy (°, 1σ): 0.03 0.03 0.03
Memory cards supported MicroSD MicroSD MicroSD
Memory card file system exFAT exFAT exFAT
Internal memory capacity (Gb): 256 256 256
External media connection type: USB Type-C USB Type-C USB Type-C
Country of manufacture:  Switzerland Switzerland Switzerland
Possible installation options Aircraft, car, backpack Aircraft, car, backpack Aircraft, car, backpack

Setting up the laser sensor

When using TOPODRONE LiDAR for ALS, the laser sensor Field-of-view angles are limited to 106 degrees due to the design feature of the applied drones (chassis). At the same time, the full view of the laser sensor (360 degrees) should be used to perform MLS. To change the angle of view of the TOPODRONE LiDAR it is necessary to perform the procedure of connecting the TOPODRONE LiDAR to the Internet using a cell phone and the web-interface of the laser sensor with local connection via Wi-Fi.

The following components and conditions are required to perform the TOPODRONE laser sensor working angle adjustment procedure:
  1. Mobile Android device (smartphone or tablet) (Only Samsung, Honor, Xiaomi phones are tested, other manufacturers' mobile devices may not work correctly) with 3G/4G/5G mobile Internet or Wi-Fi network with Internet connection;
  2. USB Type-C OTG adapter (supplied with the package);
  3. USB cable for connection to a mobile device (supplied with the smartphone/tablet);
  4. TOPODRONE LiDAR;
  5. Power supply (supplied with the kit) or power from the aircraft via a cable with LEMO 6 pin connector or power cable from Li-Po battery (supplied with the mobile kit);
  6. Computer or other mobile device with any internet connection.
To connect to the web interface of the TOPODRONE LiDAR via a local network, the following steps must be performed strictly in the following order:
  1. Make sure that the TOPODRONE LiDAR is securely located on the back cover on a flat, stable horizontal surface or attached to the aircraft / mobile vehicle mount on a standard mount. Due to the gyroscopic torque, the TOPODRONE LiDAR may start to move if it is not securely positioned and fall down after it is turned on. Never place the TOPODRONE LiDAR on an uneven, slippery surface or on its side with the lens touching the surface. 
  2. Power up the TOPODRONE LiDAR by connecting it to a power supply unit or aircraft or to a external PowerBank. To power the TOPODRONE LiDAR from the PowerBank, it must be turned on with a short press of a button on a PowerBank.
  3. Wait for the TOPODRONE LiDAR to turn on and boot up (once the TOPODRONE LiDAR has finished booting up, the LED should be solid green and the yellow LED should turn off). 
  4. Using a computer or mobile device, go to the available Wi-Fi networks section and find the network with the name TOPODRONE_LIDAR
  5. Connect to this network using the password topodrone.
  6. Then on your computer or other mobile device, open your browser and click on the link: http://192.168.10.1:10977/
  7. In the web interface that opens, find the line with the values Azimuth FOV Start XXX / End YYY, where XXX – is the angle in degrees of the beginning of the scan are, YYY – angle in degrees of the end of the scanning area.
  8. For ALS set the FOV Start: 217 End: 323. With this values the field of view (FOV) will be 106 degrees to the bottom of TOPODRONE LiDAR (53 degrees to the left and right of the nadir). After entering the desired values, click the Save button.
  9. For MLS, set the FOV Start: 000 End: 359. With this values the field of view (FOV) will be 360 degrees. After entering the desired values, click the Save button. 
  10. Make sure that all other settings except the recording start and end angles match those in the screenshots below:


    Setting the Laser Scanning Sensor Parameters for the ALS

    Setting the Laser Scanning Sensor Parameters for the MLS
  11. The TOPODRONE LiDAR settings are now complete. Turn off the power to the laser scanner, disconnect all cables and put the equipment in the case if necessary.
To connect to the web interface of the TOPODRONE LiDAR via the Internet, the following steps must be performed strictly in the following order:
  1. Make sure that the TOPODRONE LiDAR is securely located on the back cover on a flat, stable horizontal surface or attached to the aircraft / mobile vehicle mount on a standard mount. Due to the gyroscopic torque, the scanner may start to move if it is not securely positioned and fall down after it is turned on. Never place the TOPODRONE LiDAR on an uneven, slippery surface or on its side with the lens touching the surface. 
  2. Power up the TOPODRONE LiDAR by connecting it to a power supply unit or aircraft or to a external PowerBank. To power the TOPODRONE LiDAR from the PowerBank, it must be turned on with a short press of a button on a PowerBank.
  3. Wait for the TOPODRONE LiDAR to turn on and boot up (once the scanner has finished booting up, the LED should be solid green and the yellow LED should turn off).
  4. Connect the USB Type-C OTG adapter and USB cable to connect to your mobile device together via the USB Type-A connector (rectangular connector).
  5. Connect the USB Type-C OTG adapter to the TOPODRONE LiDAR's USB Type-C connector.
  6. Connect the USB cable for mobile device connection to a mobile device (smartphone or tablet) running Android OS
  7. Make sure your mobile device has an active Internet connection via 3G/4G/5G or Wi-Fi.
  8. In your mobile device, go to the menu: settings / connections / mobile hotspot and modem / USB modem mode pr Tethering mode (may differs in different languages).
  9. Then, on your computer or other mobile device, open your browser and click on the following link: http://node.gnss.cloud:10977/
  10. In the web interface that opens, find the line with the values Azimuth FOV Start XXX / End YYY, where XXX – is the angle in degrees of the beginning of the scan are, YYY – angle in degrees of the end of the scanning area.
  11. For ALS set the FOV Start: 217 End: 323. With this values the field of view (FOV) will be 106 degrees to the bottom of TOPODRONE LiDAR (53 degrees to the left and right of the nadir). After entering the desired values, click the Save button.
  12. For MLS, set the FOV Start: 000 End: 359. With this values the field of view (FOV) will be 360 degrees. After entering the desired values, click the Save button. 
  13. Make sure that all other settings except the recording start and end angles match those in the screenshots below:


    Setting the Laser Scanning Sensor Parameters for the ALS

    Setting the Laser Scanning Sensor Parameters for the MLS
  14. The TOPODRONE LiDAR settings are now complete. Turn off the power to the TOPODRONE LiDAR, disconnect all cables and put the equipment in the case if necessary.

The procedure for connecting the TOPODRONE LiDAR to the Internet (steps 1-8) can also be used by TOPODRONE Technical Support for remote diagnostics.

The TOPODRONE LiDAR settings are saved until the next time you change them. It is strongly recommended to memorize or make a note of the currently set laser sensor angles. In case of incorrect initial settings, e.g. setting the ALS at the time of performing an MLS, the data from the excluded angles is not saved and cannot be retrieved in any way. On the contrary, if the TOPODRONE LiDAR is set to 360 degrees when performing ALS, the data will be more than 3 times redundant.

TOPODRONE LiDAR to backpack installation


To install the TOPODRONE LiDAR on the backpack, you need the following components included in the package:

1.jpg

1.  TOPODRONE LiDAR - 1 pc.

2.  TOPODRONE Backpack - 1 pc.

3.  Backpack LiDAR mount with antenna cable - 1 pc.

4.  LiDAR mount spacer - 1 pc.

5.  GNSS Antenna - 1 pc.

6.  Power Bank - 1 pc.

7.  LEMO 6 PIN - USB Type-C power cable - 1 pc.

8.  Pole (30 cm) - 1 pc.

 9.    Screw M3x8 - 4 pc.
10.  Screw М4х8 - 1 pc.
11.  Screw М5х8 - 1 pc.
12.  Screw 5/8" - 11 UNC  x 3/4" - 1 pc.
13.  Hex 2.5 screwdriver - 1 pc.
14.  Hex 3 screwdriver - 1 pc.
15.  Hex 4 screwdriver - 1 pc.

It is strongly recommended to use a protective soft cover for the TOPODRONE LiDAR to avoid the risk of damaging the laser scanning lens! For better clarity, in the photos shown, the TOPODRONE LiDAR is shown without the case.

To install the TOPODRONE LiDAR on the backpack, follow the steps below:

1. Place the TOPODRONE LiDAR (1) on a flat surface as shown in the photo.

143A9353.JPG

2. Using a Hex M2.5 screwdriver (13) and M3x8 screws (9), install the laser scanner mount adapter (4) as shown in the photo.3.jpg3. Manually screw the GNSS antenna (5) onto the Backpack Mount with antenna cable (3) using a 5/8“ - 11 UNC x 3/4” screw (12) as shown in the photo.

4.jpg

4. Connect the antenna cable (3) to the GNSS antenna (5), avoiding bends as shown in the photo.

5.jpg

5. Using a Hex 4 screwdriver (15) and an M5x8 screw (11), mount the TOPODRONE LiDAR to the fastening part of the backpack (3) without pinching the antenna cable.

6.jpg

6. Position the TOPODRONE LiDAR on the mount at the required angle and fix it with the M4x8 screw (10) using a Hex 3 screwdriver (14).

7.jpg

7. Connect the antenna connector of the LEMO mount (3) to the TOPODRONE LiDAR (1)

12.jpg

8. Screw the pole (8) to the backpack attachment (3).

8.jpg

9. Screw the pole (8) to the backpack (2) as shown in the photo. The LED of the TOPODRONE LiDAR should be positioned backwards.

9.jpg

10. Connect the LEMO 6 PIN to USB Type-C power cable (7) to the TOPODRONE LiDAR (1).

10.jpg

11. Connect the LEMO 6 PIN to USB Type-C power cable (7) to the Power Bank (6) and apply power.

11.jpg

12. Put the Power Bank (6) into the backpack pocket (2) and wait for the TOPODRONE LiDAR (1) to turn on and initialize. Next - put on the backpack as shown in the photo and start the MLS.

143A9405.JPG

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TOPODRONE LiDAR to mobile mount installation

To install the TOPODRONE LiDAR on the mobile mount, you will need the following components included in the kit:

0.jpg

1.  TOPODRONE LiDAR - 1 pc.

2.  Mobile mount base - 1 pc..

3.  Mobile mount arm - 3 pc.

4.  Mobile mount suction cup - 3 pc.

5.  GNSS antenna - 1 pc.

6.  Pole (30 cm) - 1 pc.

7.  M3x10 screw - 10 pc.

8.  М5х10 screw - 2 pc.

 9.    5/8" - 11 UNC  x 3/4" screw - 1 pc.
10.  Mobile mount spacer - 2 pc.
11.  Hex 2.5 screwdriver - 1 pc.
12.  Hex 4 screwdriver - 1 pc.
13.  Antenna cable - 1 pc.
14.  LEMO 6 PIN - USB Type-C power cable - 1 pc.
15.  Power Bank - 1 pc.

It is strongly recommended to use a TOPODRONE LiDAR protective soft cover for to avoid the risk of damaging the laser scanning lens! For better clarity, in the photos shown, the TOPODRONE TOPODRONE LiDAR is shown without the case.

1. Install the two mobile mount spacers (10) on the TOPODRONE LiDAR (1) with 8 M3x10 (7) screws using a Hex 2.5 (11) screwdriver as shown in the photo:

1.jpg

2.jpg

2. Install TOPODRONE LiDAR (1) on the mobile mount base (2) with two M5x10 screws (8) using a Hex 4 (11) screwdriver as it shown at the photo below. Be extremely careful at this step!

Hold the TOPODRONE LiDAR (1) so that it does not fall and proceed to step 3. Use the cover to protect the lens! It is especially important in this step!

3.jpg3. Set the TOPODRONE LiDAR (1) at the required angle on the main part of the mobile mount (2) and fix the position with two M3x10 screws (7) using a Hex 2.5 screwdriver (11).

4.jpg

4. Connect the mobile mount arm (3) to the suction cup swivel mechanism (4), repeat with all parts. 

5.jpg

5. Connect the mobile mount arm (3) with the other side to the hinge mechanism of the mobile mount base (2). If necessary, manually loosen or tighten the thumbscrew. Once the hinge mechanisms are in alignment, manually tighten the thumbscrew. Repeat with all parts.

6.jpg

6. Install the pole (6) to the mobile mount base (1). Manually tighten the 5/8" - 11 UNC  x 3/4" screw (9).

7.jpg

7. Screw the GNSS antenna (5) onto the pole (6).

8.jpg

8. Connect the GNSS cable (13) to the GNSS antenna (5), taking care not to bend it.

9.jpg

9. Connect the antenna cable with the LEMO connector (13) to the TOPODRONE LiDAR (1) it clicks into place.
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10. It is recommended to fix the antenna cable in the area of the pole (6) with a GNSS cable velcro (13) as shown in the photo.

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11. Clean the surface of a vehicle with wet and dry wipes. Remove the protective caps from the suction cups (4). Install the mobile mount on the car with the suction cups (4) using the pump. It is necessary to pump the pump until the pump stops pumping out air and the suction cup is completely glued to the surface. The photos below show the process of pumping the air out of the suction cups without removing the suction cup caps.

12.jpg12. Connect the LEMO 6-Pin connector of power cable (14) to the TOPODRONE LiDAR (1), it clicks into place. 

13.jpg

13. If necessary, use the beam wrenches to adjust the position of the mobile mount on the vehicle so that it is level. The photos below show how to mount the TOPODRONE 100+ laser scanner on the vehicle at 30 and 0 degrees respectively.
Note: in the photos below, a non-standard 20 cm long milestone is used, which is different from the one supplied.

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14. Connect the USB-C port oft the power cable (14) to the Power Bank (15) and apply power. Wait for the TOPODRONE LiDAR to initialize.

14.jpg

It is recommended to check the grip of the suction cups every hour, especially at sub-zero temperatures!

Do not install the suction cups on dirty, dusty surfaces, as well as on joints of planes and parts with seams and gaps. 

Assembly of the Mobile Scanning Kit

Additional equipment required for kit assembly:

  1. Insta 360 X4 camera;

  2. microSD memory card for the Insta 360 X4 camera (128 GB recommended);

  3. Camera mounting bracket for Insta 360 X4;

  4. Extended antenna cable (70-80 cm);

  5. Mounting screw for securing the GNSS antenna;

  6. 1/4-inch hex socket flat head screw for attaching the camera to the bracket.

Camera Mounting Bracket Appearance

The bracket dimensions are 195×73×28 mm. The top hole is designed for the GNSS antenna mounting screw. The bottom hole is for the 1/4-inch hex socket flat head screw used to attach the camera to the bracket. The bracket is then screwed onto the pole.

Крепление Insta 360_1.jpgКрепление Insta 360_2.jpg

Крепление Insta 360_3.jpgКрепление Insta 360_4.jpg

Крепление Insta 360_5.jpgКрепление Insta 360_6.jpg

Крепление Insta 360_7.jpg

Assembly Procedure for the Insta 360 X4 Camera Shooting Kit

The kit is assembled using the standard procedure, with an additional step for camera installation. Sequence of operations:

1. Install the camera into the bracket.

Крепление Insta 360_8-9.webp

2. Mount the bracket on the pole.

3. Install the GNSS antenna.

IMG_20250806_165218.jpgIMG_20250806_165221.jpg

IMG_20250806_165224.jpgIMG_20250806_165302.jpg

Insta 360 X4 Camera Settings

Before installing the camera into the bracket and starting data collection, remove all additional accessories from the camera, such as protective cases and lens covers. The presence of any foreign objects on the camera leads to data defects and is not permitted.

The camera configuration parameters are provided in the table below.

Setting Setting value Setting value
Data acquiring mode Video 360° Timelapse 360°
Scene selection mode MegaView -
Resolution 5.7К 5.7К
Frame Rate 30 30
Interval - 0.5
Data Collection Methodology

The field work procedure is as follows:

  1. Assemble the mobile kit with the TOPODRONE laser scanner and camera.

  2. Install the mobile kit on the vehicle.

  3. Turn on the laser scanner, wait for data recording to begin, then turn on the camera and start video recording.

  4. Perform a calibration maneuver and proceed with data collection in the survey area.

  5. After completing the survey route, turn off the scanner and the camera.

You can learn more about the mobile laser scanning methodology on the page: Mobile Laser Scanning (MLS)

Installing TOPODRONE LiDAR on DJI Matrice 300 / M350

The following components and tools are required for installation:

Version 1, powered by SkyPort connector

3EIDimage.jpg
  1. TOPODRONE LiDAR
  2. Mounting pad with dampers
  3. Dovetail mount
  4. A set of mounting screws M3x6
  5. A set of mounting screws M4x10
  6. A set of mounting screws M3x8
  7. A set of mounting screws M3x10
  8. Helix antenna
  9. LEMO 6 PIN – SkyPort Cable
  10. Mounting the "spider" antenna with a cable
  11. USB Type-C OTG Adapter
  12. USB Type-C / USB Flash Drive
  13. Thread lock "Blue"*
  14. 2.5mm hex screwdriver *

Version 2, powered by Type-C connector

4Kz1image.jpg
  1. TOPODRONIC LiDAR
  2. Mounting pad with dampers
  3. Dovetail mount
  4. A set of mounting screws M3x6
  5. A set of mounting screws M4x10
  6. A set of mounting screws M3x8
  7. A set of mounting screws M3x10
  8. Spiral antenna
  9. LEMO 6 PIN – USB Type-C Cable
  10. Mounting the "spider" antenna with a cable
  11. USB Type-C OTG Adapter
  12. New USB Type-C/USB Adapter
  13. Thread lock "Blue"*
  14. 2.5mm hex screwdriver*
  15. Phillips Screwdriver*
  16. 1.5mm Hex Screwdriver*

* Not included with the TOPODRONE LiDAR.


Step 1. Remove the drone's cradle from the case


Step 2. Install the cradle on the drone


Step 3. Flip the DJM 300 drone


Step 4. Using a 2.5mm Hex screwdriver, unscrew the two black screws and set them aside


Step 5. Install the mounting pad on the bottom of the drone

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Step 6. Using a 2.5mm Hex screwdriver, screw in 2 M3 x 10 screws


Important! Use the thread retainer in this step! Tighten the screws tightly during installation.

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Step 7. Using a 2.5mm Hex screwdriver, screw in the 2 black screws obtained in step 4


Important! Use the thread retainer in this step! Tighten the screws tightly during installation.

image.png

Step 8. (Execution 1). Remove the cover from the SkyPort connector of the LEMO 6 PIN – SkyPort cable

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Step 9. (Execution 1). Remove the cover from the SkyPort connector of the drone

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Step 10. (Execution 1). Connect the cable to the SkyPort connector of the drone

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Step 8. (Execution 2). Using a phillips screwdriver, unscrew the 2 screws of the USB Type-C cover


Step 9. (Execution 2). Install the USB Type-C cable connector into the drone, following the key pattern

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Step 10. (Execution 2). Using a 1.5mm hex screwdriver, tighten the locking screw


Step 11. Turn over the DJI 300 RTK, remove the bed

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Step 12. Install the "spider" type antenna mount on the top of the drone


Step 13. Secure the mount using M3x6 screws and a 2.5mm Hex screwdriver.


Important! Use the thread retainer in this step! Tighten the screws tightly during installation.


Step 14. Lay the cable along the housing as shown in the photo


Step 15. Put the TOPODRONE LiDAR on the drone bed, the antenna connector should be on top


Step 16. Install the dovetail mount and tighten the M3x8 screws with a screwdriver


Important! Use the thread retainer in this step! Tighten the screws tightly during installation.


Step 17. Install the TOPODRONE LiDAR on the quick-release mount

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It is recommended to install LiDAR from front to back

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Step 18. Screw in the locking wing screw


Шаг 19. Винт должен быть закручен плотно, но без чрезмерного усилия


Шаг 20. Подключите антенный разъём к лазерному сканеру


После подключения антенного разъема он должен выглядеть как на фото


Step 19. The screw must be screwed tightly, but without excessive force


After connecting the power connector, it should look like in the photo


Step 22. Screw the GNSS antenna onto the spider-type mounting connector.


The GNSS antenna should be twisted tightly, but without excessive force


Step 23. In order not to lose the protective caps, you can connect them together


Step 24. The drone assembly with TOPODRONE LiDAR looks like this

 


You can start performing ALS

* Due to the partial overlap of the sensors, the use of a lower visual positioning system with TOPODRONE LiDAR installed is not recommended. It is recommended to land drones during ALS in manual mode to reduce the impact on the landing gear and TOPODRONE LiDAR during landing. The manufacturer is not responsible for the stability of operation of the DJM 300 RTK drone with the lower visual positioning sensors turned on.

Switching on and initializing the TOPODRONE LiDAR

After correct installation on the drone or backpack, connection of external GNSS antenna and power cable, TOPODRONE LiDAR performs the power-up and initialization procedure. After the initialization a data recording starts on the internal storage of the TOPODRONE LiDAR or on the external memory card if it is installed. The priority of recording on the external memory card. For successful initialization it is necessary to ensure proper installation of the TOPODRONE LiDAR on the appropriate media, the presence of GNSS signal, as well as immobility of the device before the start of data recording.

After connecting the TOPODRONE LiDAR to the power supply, it will make a short beep and the LED will turn green. Then, the LED of the laser scanner will light up according to the indication table. If there is a stable GNSS signal and there are no errors, the laser scanner will switch the LED color to constant blue after some time. The succesful TOPODRONE LiDAR LED indication is shown on photos below.

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After the initialization, the data is written to the internal memory of the TOPODRONE LIDAR. It is possible to stop data recording by the following events:

  1. Power interruption, in which case the data will be successfully overwritten due to the internal power system.
  2. Connecting external media to the USB Type-C port (only available when writing data to the internal memory).
  3. Running out of free space on the storage medium (memory card or internal memory).

The file system format of the TOPODRONE LiDAR MicroSD is exFAT.

The first activation (cold start) of the laser scanner in an open area with a sufficient GNSS signal level (8 or more satellites) may take more time to pass the initialization procedure than subsequent activations. As a rule, at the first start of the TOPODRONE LiDAR it takes no more than 60 seconds until the start of data recording. In case of subsequent power-ups (warm start) the initialization procedure is faster (20-30 seconds). In case of starting to move along the route, initialization may not be performed correctly during the movement.

It is necessary to check the LiDAR initialization status each time before launching the drone on an automatic mission or starting a walking route, as well as before finishing the work. In case the initialization status at the end of the route is not displayed by the constant LED, it means that the GNSS signal was lost during the route. In this case, the data received from the TOPODRONE LiDAR will be unsuitable for further post-processing.

Overlaps between scans and the height of the scanned objects

During the flight, TOPODRONE LiDAR scans an area of the surface of a certain width, which is called a "scan". The width of the scan is determined by the technical characteristics of the sensor, the operating altitude of the flight, as well as the difference in terrain.

For correct postprocessing of the data obtained from TOPODRONE LiDAR, it is necessary that neighboring scans have a common overlap. It is recommended to provide at least 30% lateral overlap to adjacent scans. Insufficient overlap between scans, especially in combination with significant relief differences, can lead to the formation of an area without data, which significantly reduces the quality of output materials.

On the other hand, a higher overlap value allows the most accurate calculation of the calibration angles of Roll, Pitch and Heading. When choosing a specific overlap value, it is necessary to take into account such parameters as the maximum length of the laser beam, the scanning angle (106 degrees for ALS) and the height of the scanned object.

To achieve optimal results when performing ALS using TOPODRONE LiDAR, it is recommended to set the following parameters when building a mission:

1

2

3

4

5

LiDAR model,

maximum beam length

Working height, m

Scan width, m

Distance between scan centers: % overlap

Maximum height of the scanned object: % overlap

30%

40%

50%

60%

30%

40%

50%

60%

TOPODRONE LiDAR 100+ и 100

120 m

50

134

94

81

67

54

15

20

25

30

60

160

112

96

80

64

18

24

30

36

70*

187

131

113

94

75

21

28

35

42

80**

136

96

82

68

55

24

32

41

49

TOPODRONE LiDAR 200+

300 m

 

90

240

168

144

120

96

27

36

45

54

100

267

187

161

134

107

30

40

50

60

110

292

205

176

146

117

33

44

55

66

120*

240

168

144

120

96

36

48

60

72

130*

260

182

156

130

104

39

52

65

78

140**

235

165

141

118

94

42

56

70

84

150**

250

177

152

126

101

45

60

75

90

Table 1. Dependence of the distance between the scan centers on the overlap and the working height.

* The specifications are given for a scanning angle of 90 degrees.

** The specifications are given for a scanning angle of 80 degrees. With such characteristics, there is a significant decrease in the density of points.

Перекрытие LiDAR.jpg

The density of the resulting point cloud depends on factors such as flight speed, altitude, and surface reflectivity. As nominal initial values, it is recommended to conduct flights at a drone flight speed of 6 m/s at an operating altitude of 60 m for TOPODRONE LiDAR 100, 100+ and 100 m for TOPODRONE LiDAR 200+ with 40% overlap.

Further changes to these parameters must be made taking into account the features of the terrain, weather conditions and the maximum height of the scanned objects.

IMU calibration pattern

Before starting each route for ALS or MLS on the TOPODRONE LiDAR, a calibration pattern must be performed after the initialization procedure. This pattern is performed to calibrate the IMU module inside the TOPODRONE LiDAR. Without performing this calibration pattern before starting the route, the data quality may not be satisfactory. During the calibration process on the aircraft, it is necessary to move in a plane at operating altitude in a circular pattern once clockwise and once counterclockwise, the sequence does not matter. An important point is the need to change the spatial position of the TOPODRONE LiDAR, in this regard, the option with rotation around its axis, similar to the compass calibration on DJI drones, is not suitable.
Performing calibration of TOPODRONE ALS laser scanner in automatic mode. There are two ways to perform the figure-eight calibration pattern on DJI drones: automatic and manual. The possibility of automatic execution depends on the flight planning software used. UgCS Pro / Expert software allows you to perform the calibration procedure in automatic mode.

To perform an automatic figure-of-eight flight in UgCS software, follow the steps below:
  1. Create a new route by selecting the desired drone profile and setting the desired parameters for return altitude, actions in case of loss of remote control signal, etc.
  2.  Using the Waypoint tool, set the takeoff point, which will be the first waypoint of the route. Set the "height above ground" parameter according to the working altitude.

    1.png

     

    Setting the waypoint before starting the calibration pattern "figure eight" in UgCS Pro / Expert software.
  3. Using the Circle Flight tool with a double left mouse click, create a circle flight so that it touches the first "Takeoff" waypoint. It is recommended to use/change the following parameters:
    1. Altitude: 60-120 m according to the working altitude for your sensor (see point 2).
    2. Range: 10-60 meters
    3. Flight speed: 6-10 meters per second
    4. Turn Type: Adaptive Bank Turn (this parameter smooths out corners)
    5. Clockwise traversal: yes (no for the second lap)
    6. Number of approximating points: 7
    7. Follow the terrain: no
    8. Altitude mode: AGL (altitude will be calculated relative to the terrain)
    9. POI – delete (by default, the POI orients the drone's front to the center of the circle)

      2.png

       

      Setting the first circle of the calibration pattern "figure eight" in UgCS Pro / Expert software. Pay attention to the necessity of deleting the POI action
  4. Using the Circle Flight tool with a double left mouse click, create a second circle flight so that it touches the first waypoint and the first circle. It is recommended to use the same parameters as in step. 3, except for the "Clockwise traversal" parameter, which should be different for the two circles. Clockwise traversal: no (yes for the second circle)

    3.png

     

    Setting the second circle of the calibration pattern "figure eight" in UgCS Pro / Expert software.

    Note the need to fly in circles in different directions.

Calibration of the TOPODRONE ALS laser scanner in manual mode.

If it is impossible to perform the calibration pattern in automatic mode (no UgCS Pro / Expert software), it is necessary to perform this pattern in manual mode before starting the flight along the main route. To do this, perform the following actions:

  1. Prepare the DJI quadcopter and TOPODRONE LiDAR for use in open terrain, according to the instructions, when there is sufficient GNSS signal strength.
  2. Turn on the drone, wait for the initialization procedure of the drone and TOPODRONE LiDAR
  3. Calibrate the DJI quadcopter compass before launching the drone, according to the drone's instructions.
  4. Performing compass calibration is strictly necessary each time before the first flight on a new terrain.
  5. Manually in P mode take off to operating altitude.
  6. When the drone reaches the working altitude, switch to "T" mode - Tripod (if available).
  7. Perform pattern using the control sticks. To fly in the first circle (clockwise), hold the left stick to the right and the right stick forward. This combination will allow the DJI quadcopter to circle while maintaining altitude. After the drone completes the first circle, without changing the right stick position (forward), change the left stick position to counterclockwise (left).
  8. In the case of "T" - Tripod mode, you can maneuver the sticks by pushing them to their extremes. Speed limitation and smoothness will be achieved due to the flight characteristics of the "T" Tripod mode. If the Tripod mode is not available in the quadcopter as one of the flight modes, we recommend that you maneuver the sticks as smoothly as possible without sudden movements.
  9. After completing the second lap pass, the calibration pattern is completed. After completing the calibration procedure of the TOPODRONE LiDAR in manual mode, send the flight task to the quadcopter and start the main part of the flight.
  10. While performing a figure-eight flight, you can control the turning radius of the drone using the Map view in the app on your mobile device, as well as visually by looking at the drone in flight in the sky.
Performance of the calibration pattern for MLS using TOPODRONE BackPack.
  1. Prepare TOPODRONE BackPack and TOPODRONE LiDAR for operation in the open terrain, according to the instructions, if there is sufficient GNSS signal strength.
  2. Make sure there are no objects of any kind within at least 100 meters: buildings, hills, fences, wires, etc. Power up the TOPODRONE LiDAR scanner with the included external battery and power cable.
  3. Wait for the laser scanner initialization procedure.
  4. Place the backpack over the operator's shoulders.
  5. Walk at a constant speed of 5-9 km/h in two circles with a radius of 10-15 meters clockwise and counterclockwise. Each circle must be closed before the start of the next stage.
  6. After completing the second lap pass, the calibration pattern is complete. You can proceed to the main task.
Performing the calibration pattern for the MLS when using a vehicle mount.
  1. Prepare the TOPODRONE car mount and laser scanner for operation in the open area according to the instructions, if there is a sufficient GNSS signal level.
  2. Make sure there are any objects within at least 100 meters: buildings, hills, fences, wires, etc.
  3. Place the car mount together with the laser scanner on the roof of the car in such a way that the cable coming out of the sensor and going into the TOPODRONE housing should face backwards in the direction of travel.
  4. Power up theTOPODRONE LiDAR scanner with the included external battery and power cord.
  5. Wait for the laser scanner initialization procedure.
  6. Perform a drive at a constant speed of 20-30 km/h forward for a distance of 50-100 meters with a return to the starting point in reverse at the same speed. Repeat this step 2-3 times.
  7. Once the passes are completed, the calibration pattern is done. You can proceed to the main task.

TOPODRONE MLS TRICKS AND TIPS.png

Airborne Laser Scanning (ALS)

The TOPODRONE LiDAR is designed to perform airborne laser scanning (ALS). To perform this procedure, you will need a drone that supports the correct installation of the TOPODRONE LiDAR and is capable of following a planned flight path. One such drone, for example, is the DJI M300/350 RTK.

TOPODRONE LiDAR ALS rules:

1. Neighboring spans (hereinafter for simplification - scans) should have a lateral overlap of 30% or more. 2. 
2. Scans should be parallel to each other
3. The drone must follow neighboring scans in forward and reverse directions
4. The movement speed of the drone with the TOPODRONE LiDAR on the main section of the ALS should be constant
5. The distance from the TOPODRONE LiDAR to the ground surface shall be constant
6. To obtain correct ALS data, it is recommended to take at least two scans
7. Use original propellers to reduce vibration
8. Do not fly in squall winds or during precipitation to reduce noise
9. After initializing the TOPODRONE LiDAR and taking off, perform a calibration maneuver before the main ALS section of each flight
10. If the flight takes more than 30 minutes, it is recommended to perform the calibration maneuver again when the session time reaches 30 minutes after turning on the TOPODRONE LiDAR.

ALS and the terrain elevation:

At insignificant height differences at the ALS location (up to 10 meters) it is allowed to fly the drone with TOPODRONE LiDAR at a fixed altitude (AMSL). The altitude of the drone flight is set relative to the altitude of the takeoff point. Accordingly, for the main part of the flight, almost any software can be used, allowing to set the flight on a circle (to perform the calibration maneuver), as well as to set the distance between parallel passages. 
If altitude differences at the ALS location (10 meters or more) are exceeded, it is necessary to use software that supports the “elevation envelope” (AGL) function for ALS route planning. The most convenient way to plan such routes is to use UgCS Expert software.

This is an example of UgCS Expert software and DJI M300/M350 RTK:

  1. Install UgCS Expert software and open it.

    1 EN.png


  2. Create a new mission and create a route for the DJI M300 RTK or DJI M350 RTK drone profile

    2-en (11).png

    3 EN.png

    4 EN.png

    5 EN.png


  3. Using the “Pattern” tool set a calibration maneuver in the form of an infinity sign as close as it possible to a route start point

    6 EN.png


  4. Set the “Length” and “Width” parameters to 80 and 40 meters respectively

    7 EN.png


  5. Set the “Altitude” and “Flight speed” parameters to the altitude and speed of the intended route execution

    8 EN.png


  6. Using the “Area LiDAR” tool set the area of ALS

    9 EN.png


  7. Set the “FOV” parameter to 106 degrees.
  8. Set the “Altitude Mode” parameter to AGL or Smart AGL for terrain envelope.
  9. Set the“Side Overlap, %” to at least 30%, recommended 40-60%.
  10. Set the “Flight height” parameter to the recommended values for the TOPODRONE LiDAR model.
  11. Set the “Speed” parameter in the range of 3-12 m/s according to the required performance and point cloud density.
  12. Set the “Turn type” parameter to Adaptive Bank Turn.
  13. Uncheck “IMU Calibration” if it is set by default

    10 EN.png

    11 EN.png

  14. Set the “Directional angle” parameter so that the corners are straight.

    12 EN.png


  15. Leave the rest of the parameters as default.
  16. Click on the “Parameters” button and select “Show elevation” to estimate the flight path relative to the terrain. If necessary, move the vertices of the area slightly. It is convenient to use the value of the dirrection angle as an integer when there are several routes.

    13 EN.png

    Снимок экрана 2024-10-24 103546.png

  17. Click on the “Parametersns” button and select “Export...” and select the option “for DJI Pilot 2”.

    15 EN.png

    16 EN.png

  18. For “Altitude” select “Relative to the ground under the 1st waypoint” and click “Continue”.

    17 EN.png


  19. Save the resulting route to a MicroSD card in *.kmz format

    18 EN.png


  20. Insert the MicroSD card into the DJI M300 RTK or DJI M350 RTK remote control and import the route


    The speed and altitude of the drone directly affect the density of the dense laser scanning point cloud.

     

     

     

     

Mobile Laser Scanning (MLS)

The TOPODRONE LiDAR is designed to perform mobile laser scanning (MLS). This process requires a minimum number of permits to conduct field work. You will not need to obtain a flight permit, avoid airspace restrictions, and minimize the risk of equipment damage in the event of a drone drop.

Mobile laser scanning can be done in two ways: using the TOPODRONE backpack or the TOPODRONE mobile car mount. The TOPODRONE backpack allows you to place the TOPODRONE LiDAR together with the external GNSS antenna and power supply on the operator. For more accurate results when using the TOPODRONE backpack it is recommended to use a vehicle such as an ATV, electric scooter or gyro scooter.

When scanning with the TOPODRONE backpack, the operator should walk with a steady gait, minimizing vertical and lateral oscillations. The main objective is to maintain a constant speed and minimize vibrations.

The main steps in performing mobile laser scanning:
  1. Preparing and mounting the equipment on a backpack or mobile mount.
  2. Switching on and setting up the TOPODRONE LiDAR and going through initialization (GNSS signal is required).
  3. Performing the calibration maneuver (moving along the infinity or forward-backward trajectory).
  4. Passages with TOPODRONE LiDAR along the main survey area.
  5. When performing long sessions (more than 30 minutes) it is recommended to perform additional calibration maneuvers every 30 minutes without turning off the TOPODRONE LiDAR to improve the quality of the result.
  6. Data downloading and/or turn off the TOPODRONE LiDAR.
General recommendations for mobile laser scanning:
Schematics of mobile laser scanning trajectories:

1EN.JPG

2EN.JPG

Step 1. General zone descriptions for the TOPODRONE LiDAR

Step 2. General view of the operator's trajectory

3EN.JPG

4EN.JPG

Step 3. Cutting roundings on curves (data post-processing step)

Step 4. Obtaining parallel scans (data post-processing step)

Mobile laser scanning is conditionally divided into 2 stages, in the first stage we perform calibration of TOPODRONE Lidar, and in the second stage we perform scanning of the object. Drive at a constant speed of 20-30 km/h forward for a distance of 50-100 meters with return to the starting point in reverse at the same speed. Repeat this step 2-4 times. This step is necessary for precise positioning of the TOPODRONE Lidar in space. After completing the passes, the calibration is done, you can start the main task. When performing the main stage of scanning it is necessary to provide at least 2 passes on the site of work, and the overlap between the passes should be no more than 15 meters (the larger the overlap the easier it will be for the program to calculate the angles of misalignment).

The technology of calculating the angles of misalignment of scans in post-processing provides for the presence of vertical objects, so if there are no vertical objects on the scanning area or their number is minimal, it is necessary to supplement the work with vertical objects to calculate the angles of misalignment.

Downloading data from TOPODRONE LiDAR

TOPODRONE 100 / 100+ / 200+ LIDARs are equipped with two ways to record data during ALS or MLS: to a MicroSD card or to the internal built-in memory. If a memory card is inserted in the TOPODRONE LiDAR, the data will be written to the memory card by default. In case the memory card is not inserted, there is not enough free space on it or it cannot be read, the TOPODRONE LiDAR will start writing data to the internal memory.

Data is written to the memory card if there is at least 6GB of free space on the memory card at the time of initialization. If the memory card initially had less than 6GB of free space or it was not available, the data recording starts by default to the internal memory of TOPODRONE LiDAR. 

Downloading data from the memory card:

In order to access the ALS or MLS data of TOPODRONE LiDAR recorded on the memory card, it is enough to turn off the power of the device, wait until the LED goes out and then remove the MicroSD card. Connect the memory card to the PC directly or, if necessary, via a card reader.

Downloading data from internal memory:

In order to access the ALS or MLS data of the TOPODRONE LiDAR recorded in the internal memory, it is necessary to download them to an external USB drive using the included USB OTG Type-C adapter or a flash drive with USB Type-C connector.

Each initialization of TOPODRONE corresponds to one set of files and, accordingly, one archive with data. After connecting the external flash drive, the TOPODRONE LiDAR starts to form an archive in *.zip format for each data set. After the archive is formed, it starts to be overwritten to the external flash drive. After the archive rewriting is finished, the TOPODRONE LiDAR compares the checksums on the internal memory and on the external flash drive. If the checksums are the same, the data of the current inclusion is deleted from the internal memory of the TOPODRONE LiDAR.

Downloading data from internal memory takes much longer than from a memory card!

1) Make sure there is enough free space on the external flash drive to load the required data. Depending on the type of LiDAR and operating time, the size of one data set can be from 1 GB to 10 GB.
2) Turn on the power of the TOPODRONE LiDAR by connecting the power supply through the LEMO 6-Pin connector. If data uploading occurs immediately after performing ALS or MLS, you can skip to step 3. 
3) Connect an external flash drive directly into the USB Type-C connector, or with a USB-OTG adapter (included). 
4) During normal operation, the LED of TOPODRONE LiDAR will change its color to flashing crimson with increasing tone according to the indication table. Flashing crimson indicates that data is being written to the external flash drive.
5) When the LED of the TOPODRONE LiDAR changes its color to green with a decreasing tone, the data recording is finished.
6) Turn off the power of the TOPODRONE LiDAR and disconnect the external flash drive.

In case of loss of overwritten data on the external USB drive, it is impossible to unload them from the TOPODRONE LiDAR memory.

To reduce the waiting time, you can use the power supply for TOPODRONE through the included power supply unit from the 220V mains without the need to assemble and turn on the drone.

Data upload speed directly depends on the supported speed class and the remaining free space of the external USB flash drive, as well as the TOPODRONE LiDAR run time.

Ground Control Points (GCP) for TOPODRONE LiDAR

To assess the accuracy of the final dense point cloud after data post-processing, it is necessary to perform GCP (Ground Control Points) georeferencing at the fieldwork stage. Under control points we understand the points, which are well interpreted on the dense cloud relative to the relief and previously taken with the help of high-precision GNSS equipment. Control points are not involved in the processing and should not be confused with ground control points.

To control the results of the TOPODRONE LIDAR, it is recommended to place control points on any flat dry surface using GNSS measuring equipment mounted on a milestone or tripod using RTK or PPK methods. 

 
GCP georeferencing to assess the accuracy of the dense point cloud of the TOPODRONE LIDAR using the Reach RS2 GNSS receiver.

The coordinate system of the control points should be similar to the coordinate system of the base station and the project as a whole. 

It is recommended that at least 1 control point be recruited on a single ALS route. 

The optimal surfaces for coordinating control points are roads, paths and other similar elements.

Frequently Asked Questions

  1. Question: what happens if I run out of free space on the memory card while recording data (ALS or MLS)?

    Answer: recording files to the memory card will stop, but recording to internal memory will not start. No further shooting data will be recorded. It is recommended that you check the remaining space on the memory card in advance and clear it if necessary. 

  2. Question: Why is it recommended for MLS to use electric transportation: scooter, scooter, etc. for TOPODRONE BackPack?

    Answer: to reduce vibrations, wave-like surges (in human gait) and a smoother overall trajectory. 

  3. Question: Why is it recommended that a ALS or MLS session not exceed 30 min?
    Answer: it has been experimentally determined that when the ALS data recording time exceeds more than 30 min. 

     

  4. Question: Topodrone LiDAR does not download data to the external flash drive after writing data to the internal memory.

    Answer: it can be one of the following reasons:

    a) When connecting an external drive to the USB Type-C connector, make sure that the external drive is properly (all the way) connected to the USB Type-C port of the Topodrone LiDAR. If you are using a USB OTG adapter, make sure it is correct.
    b) The TOPODRONE LiDAR has not been initialized before being prepared for use for ALS or MLS. For example, due to an unconnected external antenna cable or insufficient GNSS signal quality. Even if GNSS data is lost during ALS or MLS, the data set in the internal memory of the Topodrone LiDAR will still be generated and available for download.
    c) The data from the Topodrone LiDAR has already been previously overwritten and deleted from the internal memory after a successful transmission.

  5. Question: is it nessesary to perforn an infinity or front-back calibration maneuver every ALS or MLS session?
    Answer: yes, calibration maneuver must be performed every time before the main area survey starting. 
    This maneuver is necessary to correctly calibrate the built-in TOPODRONE LiDAR's IMU.

  6. Question: TOPODRONE LiDAR does not initialize, what should I do?
    Answer: check the following points
    a) It is necessary to check the adequacy of the GNSS signal in the place where flights are planned 
    b) Check that the antenna cable is connected and the GNSS antenna is installed correctly 
    c) The laser scanner is in motion Set the laser scanner stationary, turn off the power, wait 20 seconds and turn it on again

  7. Question: The TOPODRONE laser scanner makes a small buzzing sound when it is turned on, is this normal?
    Answer: This is a normal sign of the rotation mechanism of the laser scanning units and is not a malfunction

  8. Question: What happens if I remove the external flash drive from the internal memory of the TOPODRONE LiDAR without waiting for the rewriting to finish?
    Answer: The last file set archive that was not successfully moved to the end will remain on the internal memory of the laser scanner until the next time the external flash drive is connected.