Transmission curves for SOT/NFI blocking filters

Tom Berger (LMSAL) has added a new routine (FG_NFI_FILTER.PRO) to the SSW tree for SOT. Like it's BFI version before it, it plots the blocking filter profiles (with optional solar spectrum overlay) for the NFI channel.

Unlike the BFI program, this one include a TEMPERATURE keyword since we have measurements at both 18 and 24C. If the keyword is set to a temperature in {18,24} the profile returned is linearly interpolated between the data profiles. Note that we have no temperature dependent data for the Barr 5896 filter, so the program does not use the temperature keyword in this case.

Discussions on whether/how to add a tunable filter profile calculation to the program are going on.