Determine the order number of a specified wavelength ECH_ORDERNUM
Use the grating equation to calculate the free spectral range and then derive the order number directly from it.
ECH_INIT must be called before calling this routine.
CALLECH_ORDERNUM (W, THETA, GAMMA, M, STATUS)
READ | W | REAL | Wavelength whose order number is to be determined (ie the order number within which it lies within the free spectral range) (Angstroms) |
READ | THETA | REAL | Echelle theta angle corresponding to the current configuration (radians) |
READ | GAMMA | REAL | Echelle gamma angle corresponding to the current configuration (radians) |
WRITE | M | INTEGER | Order number corresponding to wavelength |
READ, WRITE | STATUS | INTEGER | Global status value |
C.J. Hirst UCL (ZUVAD::CJH)