In this article I will do my best to describe the systems I have used in order to help track high altitude balloons launched by the Columbus Space Program. Hopefully it will be useful to others.
Most of the radio equipment discussed operates within the Amateur Radio service and requires an Amateur Radio license in order to operate a transmitter (anyone can operate a receiver on Amateur Radio frequencies without a license). Most of the radio equipment uses APRS which enables GPS-equipped devices to transmit data bursts that tell anyone listening the location (longitude and latitude) of the device, and often other information as well.
Trackee is not a commonly used term, but I will use it to refer to equipment that flies with balloon payloads and enables them to be tracked, usually via the APRS.
Kantronics KPC-3, Kenwood handheld transceiver (HT), GPS
Byonics MT-1000
Argent Data Systems Friendcom F-301 radio (no longer available from Argent Data Systems) with integrated Tracker3 T3-Mini and GPS.
Argent Data Sytems Tracker3 T3-Mini, SRB MX145 radio transmitter, and GPS.
Due to government regulations many GPS receivers are designed to stop providing position information when the receiver is above approximately 60,000 feet. There are perfectly legal GPS receivers that will work above 60,000 feet. When choosing a GPS receiver to fly on a trackee, it's important to choose one that will work above 60,000 feet.
A tracker is a set of equipment used by a ground station, often in a vehicle, to determine the location of a balloon payload's trackee. There are many ways to assemble such a ground tracker which can be used to help monitor, chase, and recover a balloon payload equipped as a trackee.
A traditional tracking setup is to equip a laptop computer with a TNC, radio transceiver, GPS receiver, and APRS software such as UI-View, YAAC, or Xastir.
Another popular tracking setup is an Android or iOS device (phone or tablet) connected via Bluetooth to a TNC and radio.