Operation:
Test out the new Rajant Breadcrumb modem with the drone. The test was to find the distance of stable video connection tested from a single base modem and drone modem (no mesh networking was tested as that was not the purpose)
Weather conditions:
Temperature +/- 10 degrees Celsius
Wind +/- 15 m/s
Cloudy
Description of Flight Day:
We met up with one of the Rajant technical engineer at an open field for wide range of flight testings.
Base station was setup with main base station laptop with flight planner( in this case Mission Planner) and Rajant breadcrumb modems for video feed. A Rajant modem (with two 2.4 & two 5Ghz antennas) on the Heli as part of the payload and a Rajant modem connected to the base station (also two 2.4Ghz and two 5Ghz antennas). The video feed was not (yet) integrated (shown in) Mission Planner but was viewed with a simplistic Onviv Viewer (as the camera was a Onviv camera) in another window.
The camera was a simple and old Onviv camera purely for testing.
Payload was a wooden board with a surface area of about +/- 1,5/m^2 (al lot of drag)
It included the camera, the Rajant modem, a battery and a small network switch
Payload was about +/- 2kg
Pre-flight checks were done to ensure safety and everything proceeded smoothly. The Heli did however struggle more than usually against the wind due to the large surface area of the payload but it still held up good.
Flight was 1km from base at its furthest.
Outcome:
The Heli held up to strong winds even with the large surface area of the payload (which made it struggle more than usual. It however remained stable enough).
The signal from Rajant base to drone remained stable up until the planned 1km distance and results were good. The Onviv video viewer however froze at the 1km mark (likely due to one dropped packet and the decoder not refreshing, since logs show that the video link was good at the 1km mark).
Learnings:
The decoder on the base station computer needs fast recovery when the video feed drops a packet or temporarily loses signal. A robust decoder script will need to be written with fast recovery, flexibility and optimization. Also a good decoder will need to be chosen (H.265 if we are going to use a powerful base station) However H265 is more resource intensive and not compatible with all systems (a Jetson will work for H265).