APRS, or Automated Packet Reporting System, is a system often used to report the position of a GPS beacon to a reciever. The APRS can automatically transmit packets on a frequency without the need of a user standing by. This allows for more freedom in terms of location.
APRS is most often used for tracking objects or sharing locations with others. The APRS is connected to a GPS antennae directly or through a third party source (see predictions). This module is often used to track ships, planes, cars, or in this case, weather balloons. The whole package is very lightweight, and can be contained in various containers, from water bottles to styrofoam boxes.
High-Altitude GPS antennasEdit
A GPS antennae specifically made for high-altitude uses can allow the user to track balloons when it is at extreme altitudes. This is especially useful when the balloon goes above 25 kilometers (~82000 ft). FAST-7 used the GT-320FW High-Altitdude GPS Receiver.
More Powerful AntennasEdit
An antennae that can transmit further means that you have a better chance to track the balloon all the way through the journey. Often times, you can lose the radio signals from the balloon because it is too high up. However, with a good antennae on the APRS, you can pick up signals throughout the journey.
While it may seem that the most rigid antennae will survive a fast fall, it is actually the more flexible ones that will survive it. While rigid antennas can break on impact, flexible antennas made of wires will simply bend to the force and survive.
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SPOT Trackers are very similar to the GPS trackers, but are used on the ground. With a clear view of the sky, SPOT trackers are the difference between finding, [comma error, please comfirm Jakedageek (talk) 06:02, August 3, 2012 (UTC)]and not finding what you're looking for: whether it's a person, or in our case, a balloon. They are capable of transmitting a customised message, location, or even a call to emergency services in a life-threatening situation.
How it WorksEdit
SPOTs are small, lightweight messengers that operate with little or no assistance from the operator; just turn it on and go. A GPS satellite provides a signal, which is used to determine the location via the SPOT's onboard GPS chip. The chip then sends the details of the messenger's location - and preselected message - to a communication satellite. The satellite relays your message to specific antennas, located all around the world; which use a global network to route the message to the appropriate network. Finally, the location and message, if any, is delivered to any combination of the GEOS Rescue Coordination Center, a cell phone, or computer.
What this means, is that if you or your payload is anywhere in the world (with the exception of some places), you can rely on the SPOT trackers to report their location to you or whoever is watching.
Please note that SPOT trackers do not work in high altitudes above 30,000 ft. Do not use this to track the balloon during flight, but to find it after it lands. SPOT trackers also require an internet connection to track, while APRS Trackers only need a packet decoder (see APRS). It is also a good idea to put multiple trackers on the balloon, as only a single tracker may make you vulnerable to failure.