Implement Elevation limits

[kmharrington]

The SATs have minimum elevation limits. I just noticed those aren't in the configurations / never checked here. So far hasn't been an issue because we just know them (48 deg for satp1 and satp3, satp2 is set there right now but might get lowered). But we should have the software check for these.

[guanyilun]

is this as simple as adding assert el > 48 or similar?

[kmharrington]

It does need to be configurable at some level, since I think SATp2's will end up being different. I guess the question is if it's better for it to be a "rule" or something that causes and error.

[guanyilun]

I think it's good to error out so whoever requested that elevation will get the immediate feedback that it's not allowed. As a rule, the requested blocks may be transformed away and the feedback may be a bit hidden in the logs.

[kmharrington]

yeah sounds good. We'll want to check all of the blocks not just the calibration target ones. Would also do el >= el_min instead of just equals.