CARP like feature?

[Antoine Megens]

Hi Moshe,

As you may know PowerFlarms offer a CARP feature (Continuous Analyzer of Radio Performance).

This measures and stores continuously the detected range of other flarms in a number of sectors around the clock.

https://github.com/dingetje/FlarmTerminal/blob/main/Docs/FTD-065-AN-Continuous-Analyzer-of-Radio-Performance.pdf

Would something like that be possible for SoftRF as well?

TIA,

Antoine

[Moshe Braner]

I've already added something similar to that a few version ago.  To quote my "under the hood" document:

Reception range analysis

From version MB155, SoftRF collects summary data about the distance and reception RSSI of aircraft that either just entered or just left reception range.  The data is stored in a file "range.txt" in the flash file system (SPIFFS on the T-Beam, FATFS on the T-Echo.)  This file is plain text with the following structure (14 lines total):
        1               # version number
        9.4,3.226,1234  # range (km), log2(range), number of samples - for "oclock=0" (straight ahead)
        ...             # similarly for each "oclock" 1 through 11
        -91.4,2.58      # average RSSI, mean square deviation
The file is read, new data appended during the flight, and a new version of the file is written after landing.  If a flight log is being recorded, the range statistics are also written as "LPLTAN,..." comment lines in the IGC file.  Samples are only taken if airborne, of other aircraft that are airborne, and at least 1km away and not at too high or low a vertical angle.  ADS-B traffic is not sampled.  The range averaging is done on a log scale, but the range numbers as plain km appear as the first item in each line in the file.  If, after enough data has been collected, the range is much lower in some directions than others, the antenna placement may not be ideal.  If the RSSI average is much higher (less negative) than -100, there is radio noise in the cockpit making SoftRF reception less sensitive.  E.g., a USB power converter may generate such noise.  If the RSSI mean square deviation is large, such noise may be intermittent, perhaps caused by a device that is only sometimes carried along or turned on.  To forget the old data and start over collecting new range data, delete the file range.txt.

[Moshe Braner]

Since the range stats are appended to flight log files (at the end but before the G-records) as comments (LPLT lines), the issue with IGC validation made these files fail the "security check".  This has been fixed in version mb164, so now IGC files generated by my version of SoftRF should be valid ("blue") on OLC and WeGlide.  (They are of course not IGC certified for badges records.)

Are people using the flight logs from SoftRF?  Let us know your experience with them.  There are different ways to store them (in flash, compressed, on SD card...), and options such as the logging interval, automatic detection of takeoff and landing, and whether to log nearby traffic (as comments in the IGC file).  Please read the documentation!