Double counting of Bistatic volume factor.

[jswoboda]

The bistatic volume factor is applied twice in the following lines:

MIPS/mips/isr_performance.py

Line 1003 in 08d626e

volume = (

and

MIPS/mips/isr_performance.py

Line 1018 in 08d626e

volume = (

• Suggestion: we comment out the $cos(\alpha)^2$ term in these lines, it's also incorrect and should be $\alpha/2$ The bistatic_volume_factor is equivalent to this through a double angle trig identity and is calculated in isr_mapper.py.