Today we hit a real milestone; more than 10 kilometers of remote or autonomous driving! This consisted of 6.7 kilometers of daylight teleoperated driving from the Carnegie Science Center, 1.415 kilometers of daylight/sunset autonomy, and 2.3 kilometers of nighttime patterned search. Especially interesting for me was the fact that the autonomous driving took place between 5 and 6pm, a time of day that can often cause problems for navigation because of the low Sun angle (the Sun sets just before 6pm). Nomad did have a slight advantage, in that it was heading primarily to the east, away from the Sun, but autonomous driving continued even while in shadow. In fact, the Science Center and field observers pointed out that during the last 400 meters of autonomous driving, Nomad did an excellent job of driving along the "road", i.e., the area of dirt and rock most travelled by other vehicles.
One of the main reasons we were able to complete such distances is the work done by Mark Sibenac in improving Nomad's response to the commanded velocity. As I've mentioned before, many separate pieces must work together to achieve the desired speed, but interrupts especially need to be handled correctly. Thanks to Mark's work, Nomad is now able to deliver about 33% more velocity than at the beginning of the summer, i.e., it now achieves real speeds of 42 cm/second. One manefestation of this is the fact that Nomad was able to drive itself autonomously over 1.4 kilometers in just one hour; this is an excellent achievement, as no earlier autonomous run of this navigation system had broken the 1 km/hr barrier.
The weather here continues to be unpredictable. Today we had very strong winds (30mph?) during the late afternoon, something that in the past had indicated even stronger winds would be coming at night. But tonight has been quite peaceful, with little wind and comfortable temperatures between 50 and 60 degrees Fahrenheit (10-15 Celsius). The wind did have some effect on our operations though. We lost our satellite link briefly several times as the wind blew the dish out of alignment, and one of our members also lost his sleeping bag. He'd left it loose on top of his tent, and by the time we thought to check on it, it had vanished into the desert. He set out with a 4 wheel drive truck in search of it, but in 30 minutes managed to find only some small pieces that had collected in a particular cranny: some of our funnels made out of soda bottles, a 50ft segment of toilet paper, the wind block for his camping stove, and other assorted tidbits, but unfortunately no sleeping bag. Fortunately he persisted, and eventually did locate his sleeping bag; over a kilometer away from our camp.
Finally, those of you unable to visit the Carnegie Science Center can now get some idea of what the experience is like. Francisco Lira of the Universidad Catolica in Santiago, Chile has created a Java applet that puts live images from the panospheric camera onto the web! You can check out these pictures by visiting the URL: http://bell.ing.puc.cl/Nomad.