CROSS-TRACK STEREOVISION USING ASTER

Advanced spaceborne thermal emission radiometer (ASTER) has been used to obtain global digital elevation models (DEMs) that cover all over the world using along-track stereovision; however, the coupling of nadir- and backward-observation is not free from some occlusion areas. Moreover, DEMs derived from optical stereovision suffer from voids due to clouds and shadows. Therefore, stereo pairs obtained from different cross-track pointing angles are investigated to obtain DEMs, which is called cross-track stereovision. Although DEMs by cross-track stereovision is produced by images acquired on different dates, the quantitative agreement is obtained, which shows that the cross-track stereovision is promising for DEM generation to fill the voids in global DEMs. Furthermore, DEMs obtained by cross-track thermal stereovision of ASTER are compared with that by along-track stereovision. Thermal infrared radiometer has an advantage of radiation measurement, which enables nighttime observation. These results show that further improvement in DEMs derived from ASTER is possible by increasing the number of possible stereo pairs.