Volume change of Las Vacas Glacier (Aconcagua, Argentina) investigated with Digital Photogrammetry and Syntetic Aperture Radar

LENZANO, MARÍA GABRIELA; EUILLADES, PABLO

Foz de Iguazú, Brasil

Otro; 2010. The Meeting of the Americas; 2010

This work shows the results of the ASTER stereoscopic image processing to calculate the volume changes of las Vacas glacier. The processing of median resolution satellite images (ASTER level 1A) from February 2001 and 2008 was performed through the satellite digital photogrammetry method (Käab, 2005). The comparison of the two generated DTM gives results that were acceptable within the parameters and precisions that can be obtained with this kind of sensor and the processing methodology. The average ice elevation change for the three profiles between 2001 and 2008 is approximately of -35 m in this glacier.   We also studied the feasibility of using an ERS1/2 tandem data pair acquired in 1997 for DTM construction in the area of interest. Despite the layover and foreshortening effects due to the high relief of the AOI, the glacier is clearly identifiable in the SAR scenes. The overall interferometric coherence is rather poor because of the combined effects of high relief and snow coverage, but portions of the glacier show good coherence values thus allowing topographic reconstruction. However the associated decorrelation noise makes difficult a comparison between the InSAR derived DTM with the photogrammetric ones.