Tiepoint editor: sigma calculation
Sigma is calculated as:
where:
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 |