DRow

are the values in column DRow in the tiepoint table

DCol

are the values in column DCol in the tiepoint table

n

are the number of active tiepoints

(n - df) * 2

are the degrees of freedom, that is the number of required tiepoints for a certain transformation

Georef tiepoints:

conformal df = 2; affine df = 3; second order df = 4; full second order df = 6; third order df = 10; projective df = 4 .

Georef direct linear:

df = 6

Georef orthophoto:

df = 3