Mars Observations

When Mars is available, it is a good target for several important tests. Flux, angular size, and elevation information is given below for two dates, along with integration times for a 1% detection (signal-to-noise = 100) of Mars, denoted as t100.

Date Angular Size Flux Zenith Angle t100 (tau=1.5) t100 (tau=1)
Aug. 20 8.3" 3200 Jy 70 degrees 2.2 hours 410 s
Oct. 5 6.8" 2150 Jy 65 degrees 0.9 hours 310 s

A zenith opacity of 1.5 or 1 has been assumed in the above estimates, as well as a surface temperature of 200K for Mars. It appears that the elevation of Mars is the limiting factor in the integration time required for a 1% detection.

Also note that if we know the integration time required for a signal-to-noise ratio of N, then the time required for a S/N of M is

tN/tM = (N/M)2

1/18/00 update:

Calibration targets for Austral Summer/Winter 2000 and Austral Summer 2001.