Sky Detailed Estimate

This option atttempts to estimate the zodiacal light from the target coordinates and the heliocentric longitude of the target. Table 6.3 in the WFPC2 Instrument Handbook is used (Handbook Versions 6.0 and earlier).

The "Low Sky" option can be checked to invoke the formal definition of "Low Sky" used in Phase 1 and Phase 2 HST proposals. In this case "Sun Angle" is ignored.