OnAirDecode DGPS beacon (WIP) with an SDR
DGPS beacons: the differential correction stations that broadcast GPS corrections (work in progress).
- In the mode list
- 283.5 - 325 kHz
What DGPS beacon (WIP) is
DGPS differential beacons, 283.5 - 325 kHz: MSK at 200 bit/s carrying RTCM SC-104 corrections. Work in progress: the station ID, carrier offset, level, frame count and the message types seen (receive only).
Frequencies and settings
OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is 283.5 - 325 kHz.
What OnAir shows
DGPS differential beacons, 283.5 - 325 kHz: MSK at 200 bit/s carrying RTCM SC-104 corrections. Work in progress: the station ID, carrier offset, level, frame count and the message types seen (receive only).
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
This is a shortwave mode, so the radio has to tune HF. An SDRplay, Airspy HF+ or an RTL-SDR in direct-sampling mode do that directly; with a HackRF an HF upconverter or a direct-sampling receiver is the usual route. A long wire or loop antenna matters more than the radio.
Receiving and the law
Questions about DGPS beacon (WIP)
Can I decode DGPS beacon (WIP) with an RTL-SDR?
An RTL-SDR can receive HF only in direct-sampling mode, which OnAir offers in its radio settings; results depend on the antenna. SDRplay and Airspy HF+ radios are better suited.
Is it legal to receive DGPS beacon (WIP)?
Receiving satellite downlinks is generally legal. Encrypted or spread content is not decoded, and voice codecs that are patented are not shipped with OnAir.
Can I try DGPS beacon (WIP) in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.