Level 2 Help for SHADY2

By default, the output pixels are stored as BYTE data.  The user may
optionally specify HALF (16 bit, signed pixels) as the output data
image format.

AZIMUTH is the azimuth of the illumination source (the 'sun') in real 
degrees measured clockwise from 'up' in the image plane.  

examples:
azimuth=0.0 	places the source at the top of the image
azimuth=90.0 	places the source to the right of the image. 

ELEV is the elevation of the illumination source in real degrees measured
from the image plane. 

examples:
elev=0.0 	puts the 'sun' at sunset
elev=90.0 	puts the 'sun' directly overhead

SSCALE is the scale in the sample direction.  Default is 208.0 which is
the DMA resolution in feet/pixel.

LSCALE is the scale in the line direction.  Default is 208.0.

ZSCALE is the scale in the Z or vertical direction.  Default is 1.0 which
is the DMA resolution in feet/dn.

For each input pixel, the cosine of the angle between the illumination 
direction and the local normal is calculated.  SCALE is a constant which,
when multiplied by the cosine, gives the output DN.