A method of elevation control points extraction assisted by
satellite laser altimeter data, which is characterized in that take the waveforms received by
satellite and the waveforms simulated from
digital surface model (DSM) of image scene reconstruction as input data, and includes two times of
waveform matching and combined process of multi-source
remote sensing data. The elevation control points could be extracted without the influence of
terrain fluctuation or urban buildings for the
terrain information of
laser spot area has been taken into account. The first time is realized by matching two groups of waveforms from the received and the simulated, and the spatial registrations between locations of
laser spots and DSM are realized. The second time is realized by matching two single waveforms from the received and the simulated, and local
system errors in DSM of laser spot area could be extracted. With the registration results and local
system errors, many applications including extraction of elevation control points could be easily developed. The invention mainly includes the following steps: (1) Preliminary refinement of orientation parameters of high-resolution stereo or InSAR images by free net adjustment; (2) DSM reconstruction with high-resolution stereo images or InSAR data; (3) dividing the received
laser altimetry data into groups; (4) Waveform extraction of the receiving group; (5) observation design for
simulation waveform group; (6)
simulation waveform acquisition through observation of DSM; (7) matching the received group waveforms with the simulated group waveforms; (8) plane position registration between laser spot and DSM; (9) matching each pair of waveforms in group between the received and the simulated respectively; (10) extraction of DSM elevation
system errors on each laser spot area; (11) extraction of image elevation control points; (12) refinement of DSM elevation, calibration of
satellite laser
altimeter sensor, combined
processing with
laser altimetry and image
remote sensing. The invention mainly solves two difficulties. One difficulty is finding footprints, or say laser spot areas, of satellite laser altimeters on stereoscopic images, InSAR images and the DSM they generate. Another difficulty is the accurate elevation extraction of laser spot areas with uneven
terrain. The invention can realize the
spatial registration between laser spot and DSM or
remote sensing in different terrain and establish spatial connection between
laser altimetry data and stereo images or InSAR data. In different terrain conditions, by the invention, the satellite laser altimetry data can be used for high-precision elevation control of 3D reconstruction / positioning of stereo images or InSAR data.