Our Chase Driver taking a well-deserved break. Fortunately the balloon slowed down near the In-and-Out Burger in Los Banos.
For tracking we used the matching XTend modem with high-gain antennae. We connected the modem to the laptop via a Sparkfun break-out board and CP2102 mini USB to serial connector. A power inverter plugged into the car's cigarette lighter kept the laptop going throughout the chase.
We used CoolTerm to read the serial data from the modem and write that out to a local file. We then ran a java application we wrote which converted that data into a GoogleEarth kml file. This provided a real-time graphical representation of the balloon location and track.
Here is the program output in GoogleEarth. Attached below is the Nimbus2000Track.kml file with which you can view the entire balloon flight on GoogleEarth.