Level 2 Help for SINPROJ

input image file, it needs to contain the label items: proj_lon, lon_cl,
lon_cr, lat_uc, and lat_lc for sinproj to work

output image file

the longitude of the leftmost pixel at the equator for the output
file. if not specified and if the size field is not specified the
default is the input file's value. should be between 0.0 and 360.0

the longitude of the rightmost pixel at the equator for the output
file if not specified and if the size field is not specified the
default is the input file's value. LON_CR is expected to be greater
than LON_CL but less than 360.0, if it isn't then SINPROJ interprets
it as a wraparound, e.g. specify a reprojection from 320.0 to 20.0
with a projection longitude of 350.0 as
  LON_CL = 320.0 LON_CR = 20.0 PROJ_LON = 350.

the latitude of the northernmost pixel at the projection longitude
for the output file. should be between 90.0 and -90.0

the latitude of the southernmost pixel at the projection longitude
for the output file. should be between 90.0 and -90.0 and should be 
less than LAT_UC

the projection longitude of the sinusoidal projection for the output
file, it usually passes through the center of the image frame. PROJ_LON
defaults to the longitude halfway between LON_CL and LON_CR. If samples
are specified instead of longitudes PROJ_LON is calculated from PROJSAMP

starting line for the output file, corresponds to LAT_UC. 

starting sample for the output file, corresponds to LON_CL

number of lines for the output file

number of samples for the output file

sample number of the output projection longitude for the output file 
it needs to be specified in terms of the input file sample numbering.
ie if the input image is 2000 samples wide and the output image is going
to be 500 samples wide and centered on the input image :

   SINPROJ inp=tst.in out=tst.out ss=750 ns=500  
   SINPROJ inp=tst.in out=tst.out ss=750 ns=500  projsamp=1000

will both give the same result

   SINPROJ inp=tst.in out=tst.out ss=750 ns=500  projsamp=250

will not work
If not specified it is calculated from PROJ_LON