#############################################################
#                                                           #
#         MODIS: Radiance to Brightness Temperature         #
#                                                           #
#############################################################

#-----------------------------------------------------------------------
#!F77
#
#!DESCRIPTION:
#    Compute brightness temperature for a MODIS infrared band
#    on Terra or Aqua.
#
#    Spectral responses for each IR detector were obtained from MCST:
#    ftp://ftp.mcst.ssai.biz/pub/permanent/MCST in directories
#    PFM_L1B_LUT_4-30-99 (Terra) and FM1_RSR_LUT_07-10-01 (Aqua).
#
#    An average spectral response for all detectors in each band was
#    computed. The detector-averaged spectral response data were used
#    to compute the effective central wavenumbers and temperature
#    correction coefficients included in this module.
#
#    NOTE: The plaform name ('Terra' or 'Aqua') is passed to this
#    function via the common block defined in 'platform_name.inc'.
#
#!INPUT PARAMETERS:
#    RAD (REAL)      Planck radiance (units are determined by UNITS)
#    PLATFORM (LONG) Platform Name: Terra=0 or Aqua=1
#    BAND (LONG)     MODIS IR band number (20-25, 27-36)
#    UNITS (LONG)    Flag defining radiance units
#                    0 => milliWatts per square meter per
#                         steradian per inverse centimeter
#                    1 => Watts per square meter per
#                         steradian per micron
#
#!OUTPUT PARAMETERS:
#    MODIS_BRIGHT  Brightness temperature (Kelvin)
#                  Note that a value of -1.0 is returned if
#                  RAD .LE. 0.0, or BAND is not in range 20-25, 27-36.
#
#!REVISION HISTORY:
#    [email protected]
#
#!TEAM-UNIQUE HEADER:
#    Developed by the MODIS Group, CIMSS/SSEC, UW-Madison.
#
#!END
#-----------------------------------------------------------------------

I got a hold of Liam's radiance to BT code, and ran it through f2py to make 
the python module mod_br.so

I have included the commands I ran in f2py_commands.txt. The first generates 
the mod_br.pyf file... 

	f2py modis_bright.f bright_m.f brite_m.f -m mod_br -h mod_br.pyf --overwrite-signature

which you then edit to put in the "intent" statments in 
the variable declarations. The second command generates the module file...

	f2py -c mod_br.pyf modis_bright.f bright_m.f brite_m.f

I ended up inlining the included code, and removing Liam's common block. f2py 
doesn't seem to know what to do with included code (or I don't know the f2py 
command to do it properly).

The main function is modis_bright(radiance,platform,band,units). Check 
modis_bright.f for the definitions. But for platform, 0==Terra, 1==Aqua

This is how I used the module...

import mod_br as mod_br
import scipy as spy
import numpy as np

mod_br.modis_bright(12.,1,31,1)
Out[16]: 316.25592041015625

radiance = np.linspace(5.,12.,10)

modBT = np.vectorize(mod_br.modis_bright)

brightTempsAqua = modBT(radiance,1,31,1)

print brightTempsAqua
[ 261.40756226  269.14404297  276.27868652  282.92977905  289.18231201
  295.09991455  300.73129272  306.11483765  311.28134155  316.25592041]

----
Geoff Cureton
SSEC, Oct 2008