Explanation of fisheye outputs

RA is right ascension (in J2000)

DEC is declination (J2000 system, we need to talk about that aspect)
HA is hour angle
xcalc is computed expectation of x coord for that cataloged object
ycalc is computed expectation of y coord for that cataloged object
BT is Hipparcos catalog photometry in their BT band
VT is Hipparcos catalog photometry in their VT band
V is computed expectation of V band magnitude
(B-V) is computed expectation of V-R color, in conventional bands
(V-I) is computed expectation of V-I color, in conventional bands
m is Tonry's computed expectation of Canon camera monochromatic magnitude, includes a color term
x is x coord of object centroid in image
y is y coord of object centroid in image
HAcalc is computed expected HA using actual x,y
Deccalc is computed expected DEC using actual x,y
alt is altitude above the horizon, presumably computed from actual x,y
rad is radius, in pixels, from center of the image
minst is instrumental magnitude, i.e. -2.5*log_10(integrated ADU within the aperture used by tphot, after sky subtraction and vignetting correction)
dm is flux uncertainty, expressed in magnitudes
sky is computed background level around the source in question
dvig is the vignetting correction that was applied in obtaining minst, in magnitudes, so we can back out the actual flux value if desired.

Mch file columns

MJD     RA        Dec      HA      xcalc  ycalc    BT     VT     V    (B-V)  (V-I)     m      x       y    HAcalc Decalc  alt    rad   minst   dm   sky  dvig