Technical Update from Alex Foessel

See some bullets with technical content (weather continues being very bad, no more accomplishment related to the robot, good opportunity to continue experiments with radar under severe visibility conditions):

The radar system keeps performing well. The radar unit has been permanently kept outside and the acquisition system inside the endurance tent. The video subsystem is unstable with the power variations produced by small generator (the other is by the robot) therefore is not used for some measurements.

Gathered several (40) frames of radar data from the same scene to understand the variation of the signal received caused by the flying snow. In the process of calculating the noise level produced by the snow. The scene is captured in digital photos. It has metal, wooden and snow surfaces.

Took frames of a scene with elevations of the sensor from 0 deg to -14 deg every 2 deg. This scenes should produce a mosaic of the terrain ahead. This while having plenty of snow flying. I plan to repeat the sequence with good weather.

Comment: as Stewart reported earlier, the stereo perception is mostly useless in this conditions, and laser has a very hard time getting range measurements that are free of false obstacles. The performance improved after giving more weight to evidence of emptiness than evidence of occupancy to the laser measurements (inspired by Hans Moravec's evidence grid application) when seeing through snowflakes. One objective for the next activities is to have qualitative measure of the degradation of radar in similar conditions.

Expedition Report from William Cassidy

29. Nov. 24, 1998, Tuesday: Patriot Hills Camp

The morning was windless and the snow had stopped falling, but the sky was still completely overcast. At least this is weather we can work in, and Sib and Nicholas left about 8 a.m. to start Nomad's warming cycle. They were back about 9 a.m. with the generator in tow because they couldn't get it started. Mike, Liam, and a couple of Chilean mechanics worked on it until after lunch and got it running again. They took the carburetor completely apart and cleaned it, changed the oil and cleaned the spark plug, which had fouled. At about 2:15 p.m., Mike and Liam left to hook up the generator to Nomad again.