In this annex a number of definitions as used by Doris are described. In Section D.2 the baseline representations are described, while in Section D.3 the definition of the interferogram is described. Section D.4 describes the definition of the polynomials. And in Section D.5 the use of the pulse repetition frequency and range sampling rate are discussed. Section D.6 describes a system of 3 equations which is frequently used to compute the position on the ellipsoid for a certain line, pixel. The way the orbits are interpolated is described in Section D.7. Finally section D.8 gives some information on the formats of the images.