530 Acre RGB Visible and Thermal IR Survey

Malli35998 · Feb 19, 2023

I recently completed a challenging 530 acres RGB Visible and Thermal IR Drone Survey over the southern end of the Hockley Salt Dome. Below are some specs and screen captures of the survey results. My goal is to identify any "thermal" anomalies and ground truth them.

RGB Visible Survey

4 overlapping sections
4 launch points close to the center of each section
5 GCPs
RTK (EOS Arrow Gold and Emlid Reach RS2+ LOCAL NTRIP)
Autel Evo II Enterprise Pro 6K V2
300 AGL
80%/75% Overlap
17 MPH
2 days
6,309 images

Thermal IR Survey

4 overlapping sections
4 launch points close to the center of each section
No GCPs
RTK (EOS Arrow Gold and Emlid Reach RS2+ LOCAL NTRIP)
Autel Evo II Enterprise V2 RTK with Dual FLIR 640R Radiometric Thermal
250 AGL
80%/75% Overlap
11 MPH
4 days (5 days including repeat section)
36,689 images (46,285 images including repeat section)

SimActive Correlator3D (Photogrammetry)
Global Mapper (GIS)
Surfer (Final Maps)

vr-pilot · Feb 25, 2023

Malli35998 said:
I recently completed a challenging 530 acres RGB Visible and Thermal IR Drone Survey over the southern end of the Hockley Salt Dome. Below are some specs and screen captures of the survey results. My goal is to identify any "thermal" anomalies and ground truth them.

RGB Visible Survey

4 overlapping sections

4 launch points close to the center of each section

5 GCPs

RTK (EOS Arrow Gold and Emlid Reach RS2+ LOCAL NTRIP)

Autel Evo II Enterprise Pro 6K V2

300 AGL

80%/75% Overlap

17 MPH

2 days

6,309 images

Thermal IR Survey

4 overlapping sections

4 launch points close to the center of each section

No GCPs

RTK (EOS Arrow Gold and Emlid Reach RS2+ LOCAL NTRIP)

Autel Evo II Enterprise V2 RTK with Dual FLIR 640R Radiometric Thermal

250 AGL

80%/75% Overlap

11 MPH

4 days (5 days including repeat section)

36,689 images (46,285 images including repeat section)

SimActive Correlator3D (Photogrammetry)

Global Mapper (GIS)

Surfer (Final Maps)

Thank you very much for sharing! Great work requiring much effort but apparently honoured with good mapping results.
530 acres, that is >210 ha, amazing... I also very much like the orange/black color line of Autel, Jackery and the landing pads! ;-)
I am about to fly a combined RGB/IR mapping for the documentation of ground breeder nests in a "vegetationally comparable" area (nature reserve) this May for an environmental organization.
I am rather planning for a 2/3 side overlap than 3/4. The narrow IR raster is the biggest challenge.

ReconnServices · Feb 28, 2023

I also want to thank you for sharing! What was your workflow like for planning the flights for this mission?

Malli35998 · Mar 1, 2023

ReconnServices said:
I also want to thank you for sharing! What was your workflow like for planning the flights for this mission?

For large surveys I generally split them into overlapping sections. The home points (launch points) are located close to the center of each section. If possible, in order to maintain VLOS, I try and keep the maximum distance out from the launch points to 1500-2000’ or less. For each section, I setup the RS2+ over a known point by surveying in a point with one of my GCPs using RTK. Once I have the coordinates of the known point, I configure the RS2+ in Manual Mode and Local NTRIP. I connect the drone smart controller via WiFi to the RS2+ and fly the survey. I repeat this process for each section until the overall survey is completed. Depending on the size of the dataset, I will process each section separately and combine in GIS application, or process the entire dataset together.

NOTE: For those interested in using Emlid Reach RS2/RS2+ Local NTRIP option, here is a practice that I use if RTK on Smart Controller is stuck on FLOAT. If this happens, then simply Restart the RS2/RS2+ Receiver using the Restart option in the Emlid Flow App. In 100% of the times that I have done this step, my RTK on Smart Controller goes to FIX position.

I attached the planning map that I used for this project.