ROCK LiDAR

How to Fly the ROCK R2A

Learn the step-by-step to fly the ROCK R2A on the DJI M210 drone.

 

Introduction

Lets go over the steps to fly the ROCK R2A LiDAR system on the DJI M210 drone. 

The steps for flying on the DJI M210 is the same for every drone system - The only different is the mounting to the drone system.  

Overview of Steps:

  1. Set up Base Station and start logging static observations at 1-second intervals
  2. Set up Drone and ROCK R2A
  3. Check Airspace and Plan Mission
  4. Turn on R2A and begin Collecting data
  5. Fly Pre-mission Calibration
  6. Fly Mission
  7. End Mission and fly in the forward direction back to the home point
  8. Land and stop the R2A
  9. Stop logging on the EMLID base
  10. Post Process using the ROCK desktop PCMaster and PCPainter

Now let's break down those steps, starting with an equipment list:

Equipment Used

  1. ROCK R2A -  LiDAR + RGB
  2. DJI M210 drone
  3. x2 TB55 batteries
  4. RC controller
  5. iPad
  6. EMLID Reach RS2 GNSS
  7. 2-m bipod
  8. Aerial Target (used but not necessary)

Installing the ROCK R2A:

Connecting the R2A to the Drone:

The ROCK R2A comes with the Skyport mounting for the DJI M200, DJI M210, DJI M300 drone systems or a toad-n-hole / dovetail mount for any other drone system.

skyportconnector

Above is the skyport connection for the DJI drone.  The installation requires you to install and twist to lock the connection.

Installing the GPS Antenna:

The second component on the R2A is a GNSS antenna. The R2A comes with a GPS antenna mast for quick attachment to the drone system.  

You will notice in the video that I did not use the GPS antenna mount.  This is because I simply misplaced it and wanted to keep recording the video :P But thats ok, I was able to simply double stick take the GPS onto the drone.  This is not ideal, but acceptable practice for the R2A. I just used some double stick tape and placed it on top of an UNUSED antenna on the drone.  I repeat: THAT ANTENNA ON THE DRONE WAS UNPLUGGED --- NEVER COVER AN ACTIVE ANTENNA WITH ANYTHING!  Thanks for reading that ;)

After you have mounted the antenna, plug the antenna into the primary port on the R2A

Placing the Base:

A well-placed Reach base is essential for achieving good RTK positioning results.

You can place your smartphone near the window in your house and it will obtain GNSS coordinates after some time, but for the R1A LiDAR such environment won't be sufficient. For the R1A to work there are special requirements for placing the base.

Clear sky view without any obstacles

The base station needs to have a clear sky view 30 degrees above the horizon. There should be no obstacles that could block the view like buildings, trees, cars, humans, laptops, etc.

Take a look at 2 pictures below. The left picture demonstrates desirable conditions for the base location. The right one is an example of bad surrounding conditions such as the reduced view of the sky, possible obstructions or vegetation nearby.

Setting up

Examples of good environments for base placement:

  • field

  • top of the hill

  • rooftop

Examples of bad environments for base placement:

  • indoors

  • urban area

  • forestry area

No electronics nearby

Electronic devices may produce RF noise that could affect the reception of the GNSS signal. Keep all electronics as far as possible from base and R1A.

Start Logging Data to your Base Station

reachviewapp-click

Turn on the REACH base and then log into the WiFi 

Login: reach:xx:xx
Password: emlidreach

Then Turn on the RAW data: RINEX 3.03 logging

Check Airspace

airmap-app

There are many ways to check the local airspace.  In the USA, AIRMAP provides a free tool to check for local airspace requirements.  Make sure you comply and follow all local rules and regulations

Mission Plan

flightcontrolapps

Mission planning is covered in another article.  For this flight I used maps made easy and generated a flight plan

Start Collecting LiDAR Data on the R2A

First start the R2A by pressing the power button on the side of the device.

Next log into the ROCK wifi

WiFi: ROCK######

Password: rocklidar

Next use your web browser to navigate to the ROCK LiDAR

website address:  192.168.12.1

Now you can verify number of satellites. 

Make sure you have 8 or greater. 

Then Start data collection.

startROCK

Now that you have pressed start. The status will  say:

  • static alignment 
Do not move the drone or LiDAR now. This will take about 5 seconds
  • Waiting for High Velocity

 

Take Flight and Calibrate

Now that the LiDAR is on and waiting for high velocity.

  1. Take off and fly a straight line for a count of 5 seconds.
  2. Fly 2 figure 8. 
  3. After this is complete you can begin flying your mission plan.

Note: the 5 seconds of straight flight is more than enough to calibrate the IMU. And typically the INS will converge on a single figure 8.  We ask you to do 2 to ensure complete calibration

Hot Swap Batteries

 

Retrieve Data for Processing

All of the LiDAR, IMU, and GPS data is written to the usb stick which is attached to the R1a. When the unit is powered off you can detach the usb and insert into your PC to begin your processing.