The image has been rectified and wavelength calibrated.
The pixels have units of erg cm-2 sec-1 A-1 arcsec-2

South is on the top, North is below the debris line.

The pixels in the X direction ( wavelength) have a scale
of 0.584 angstroms/pixel.

The pixels in the Y direction (spatial) have a scale of
0.0244 arcseconds/pixel.

Pixel 601 in the x direction has a wavelength of 1425.0
Pixel 512 in the y direction is the central pixel in the
spatial direction.

The acqusition has an uncertainty of 0.025 arcsec. The
position offset as measured on the WFPC2 frame has an
error of < 0.011" ( ~0.25 PC pixels)
the slew has an error of < 0.01" 
Therefore, the error in centering the 0.5" apeture on 87A
is on the order 1 pixel.

Absolute wavelengths across exposures is 1.0 pixels.
Absolute photometry ~10% 
Relative photometry (with an exposure) ~5%