hi im on a team that's building a small sub-orbital imaging satellite it goes up about 3km and deploys chute at apogee and we would like to be able to track it all the way down how many stations would we need and how would we build those?
Not using the word "satellite" sounds better since satellites go into orbit by definition, so "sub-orbital satellite" makes no sense.
As to your original question, I don't think you need multiple tracking stations to track something falling from only 3 km. Just get yourself a GPS tracker from Featherweight or Eggtimer (you have to solder Eggtimer stuff together) and you'll be golden.
well right now i am trying to make this as simple as possible we wont be doing video only pictures so all we hopefully need is speed and altitude and coordinates of touchdownNeed more information.
What data do you want back?
Do you want video?
What country are you in?
What license do you have?
Simple version is US hobby frequencies are 915mhz, 2.4ghz and 5.8ghz. Plus 433 mhz with license. Lower frequency gives longer range and lower data rate but at 3km, all of those will work with the right antennas. You have a link budget based on your wavelength, data rate, encoding and antennas.
Video is typically 2.4ghz or 5.8ghz, telemetry on 915mhz.
For 3km take a look at what the long range drone folks are doing and there are lots of off the shelf solutions for video with a flight dipole antenna and patch ground antenna. We use a USB dongle that gets the video straight into the laptop. Likewise any altimeter that does serial data out can be paired with a drone 915mhz data radio to get data back to a ground station that plugs into a laptop. These are sold by many drone vendors as a pair with one end having a USB plug.