SSTV: slow scan tv
Sending low resolution pictures very slowly (90s transmisison per pic) using frequency modulated analog signals at low bandwidth. This needs to be picked up ourselves with a hand held radio and decoding using a phone app or a computer program. This is a ONE WAY comms method (from balloon to ground ONLY).
APRS: automated packet reporting system
Sending data, position, atltiude, callsign, to receive stations all around the world. This is a low bandwidth DIGITAL signal that is frequency modulated. No need to pick up ourselves, will be automatically uploaded to aprs.fi. This is a ONE WAY comms method (from balloon to ground ONLY).
ATV: amateur TV
Can be digital or analog (in our case it is analog), amplitude modulated signals, extremely high bandwidth (several MHz), live stream television. Need old huge TV for receiver. This is a ONE WAY comms method (from balloon to ground ONLY).
(G)FSK, OOK
ValBal's long range digital radio system used to send any information we want at variable speeds & bandwidths. Can get anywhere from 500bps to 1Mbps, and anywhere from 1000km to 10km range depending on speed and antenna type. Need personal receiver, demodulator, rpi, to upload to HABMC. Eventually will be used to have 1Hz refresh rate on HABMC for vb and give active control. This is a partial duplex comms method (bidirectional, but not at the same time).