The ground sample distance values: Vec4D.X: Ground sample distance for a raster step of (1|0), i.e. along the X-axis. Vec4D.Y: Ground sample distance for a raster step of (0|1), i.e. along the Y-axis. Vec4D.Z: Edge length of square that has the same area as the parallelogram defined by the ground vectors corresponding to the raster steps of (1|0) and (0|1). Vec4D.W: Angle (in degrees) between the ground vectors corresponding to the raster steps of (1|0) and (0|1).
Computes the ground sample distance of this raster.