There are several transformations that can be used when georeferencing a raster:
1st order Polynomial (affine)
2nd order Polynomial
3rd order Polynomial
Are there any specific rules or rules of thumb, about which transformation should be used with a particular raster?
For example a particular transformation should generally be used with aerial photographs & another should be used with satellite imagery while a third should be used while digitizing maps?
Is there any book which explain the mathematics behind this in detail?