L1G product chemistry and geometry, including a （ organized ） output map projection, image orientation, pixel grid cell size, resampling, user-specified kernel parameter has been modified. Models the sensor compensation algorithm by using data generated by the onboard computer during imaging spacecraft and. By sensor and focal plane detector placement information in image evaluation system (IAS) calibration parameter file (CPF) also are used to improve overall geometrical accuracy. Result product is free from （ deviant Nom from for example, attitude), and Earth (for example, rotation and curvature) related strain sensors (for example, jitter, view angle effect) and satellite. Residual error to the systematic L1G products is less than 250 meters (1 Sigma) in flat areas of sea level. Is not used the ground control or relief model systematic L1G correction process to achieve absolute geodetic accuracy.