It is important to prepare for everything before each launch. One of the most important things to research is the predicted path of the balloon. You don't want the balloon to land in a city, a lake, or a mountain because it would be difficult to retrieve the payloads. The best landing spot is in the desert or the plains. Also, you don't want to get in the way of airports or restricted areas. There are various different software that can help predict the path the balloon will take and the landing spot a few days before the actual launch .
CUSF is a balloon tracking program created by the University of Cambridge. The software takes various information from the user, takes the wind information from a database, and creates a prediction as to where the balloon might land. The predictions are pretty accurate, and the software is easy to use. The GUI consists of a full-window map with a information box on the bottom right corner. The software asks for various information such as launch point, ascent rate, launch altitude, and burst height in metric units. The program then maps the predicted track of the balloon on a map, allowing users to choose the best launch spot .
An on-board predictor goes up with the balloon and uses GPS data to form real-time predictions. The program uses the knowledge that the launch point, the burst point, and the landing point is linear (provided that the balloon stays in the same area with the same wind vectors). Also, the ratio of the distance between the Launch point and Burst point to the distance between the Burst point and the Landing point is the same as the ratio of the ascent rate to the descent rate.
Balloons with On-Board PredictorsEdit
FAST-7 was launched by Flying Apple Space Technologies, based in Las Vegas, NV. The on-board predictor compromised of a GPS antannae, an arduino, and a APRS transmitter. The arduino was programmed to take value points, run them through an algorithm, and send the predictions down via radio. The predictor stopped sending signals 15 minutes after launch, and the cause for failure is unknown. The predictor transmitted on N9VAR-13.