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dl9rdz / rdz_ttgo_sonde

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DFM sondes need validity checks regarding their position #244

Open dm5tt opened 2 years ago

dm5tt commented 2 years ago

Describe the bug

I'm observing a lot of DFM radiosondes from the Calw military area.

From time to time there seem to be some position glitches causing the sonde to jump >100km.

(RS41 is having no issues at all. Even at lowest SNR.)

To Reproduce

Receive a DFM radiosonde with low SNR (-99dBm to -102dBm).

I'm not sure if the sonde causes the glitches itself or it's getting caused by bitflips slippin' through the checksum due to a bad signal.

Expected behavior

  1. Average the last 50 position frames
  2. Filter out position that seem to be not plausible (>100km)

Screenshots

image

Version and specific configuration:

Thank you!

LukePrior commented 2 years ago

I don't think this would be possible within the main program but the map interface might be able to handle it. We have a similar system in SondeHub which should prevent the upload of frames like that.

LukePrior commented 2 years ago

Also there are just more validity checks that can be done on DFM sondes, I believe this is planned for the next master version.

TarmoKolli commented 2 years ago

I have the same problem with DFM sondes. Unfortunately, my antenna only sees the eastern sky, but a few tens of kilometers away from me is a military area from which the signal from the sondes fired is distorted. Therefore, my receiver sends the last sonde information to the server with the penultimate sonde serial number. bug

dl9rdz commented 2 years ago

There should be some enhancements in the latest version.

Serial numbers for DFM are always cleared after 30 Minutes. They are also cleared, if a position deviates substantially from the previously decoded position. Let me know if that fixes the issue,

TarmoKolli commented 2 years ago

I'll let you know as soon as possible. Unfortunately, this can take time, as the DFM-09 probes are used by the military, sometimes during exercises.

TarmoKolli commented 2 years ago

Two DFM09 sondes were sent today and the picture is better, but unfortunately my receiver has sent information about one non-existent 60019549 sonde. bug2