Download - GLIMS: Global Land Ice Measurements from Space

Chapter 3Database3.1 Satellite DataIn the past several studies on Austrian glaciers have been carried out using remotesensing. Studies on the Tyrolean glaciers using Landsat data, are reported by Paul(Paul, 1995), Paul (Paul, 2002D), Rott (Rott, 1976), Rott and Markl (Rott andMarkl, 1989) and Hall et al. (Hall et al., 2003). Paul used Landsat 5 TM datato derive changes in the glacier area. Rott (Rott, 1976) used Landsat 1 MSS (andLandsat 2 MSS data) to analyse the snow cover of the central Tyrolean glaciers.Knap and Reijmer (Knap and Reijmer, 1998) and Greuell and de Ruyter de Wildt(Greuell and de Ruyter de Wildt, 1999) measured anisotropic reection over meltingglacier ice in the spectral range of Landsat TM bands. Nagler (Nagler, 1996) usedLandsat TM data to classify snow and glaciers and to verify SAR data analysis. Hecalculated planetary albedo from the Landsat images and used dierent thresholdsto derive glacier and snow maps.In this thesis data of the two instruments, Landsat 5 TM and the ASTER instrumentonboard of the Terra satellite, are used for monitoring the Stubaier glaciers. TheLandsat 5 TM satellite was launched on the 3 rd of March in 1984 and carries thesame instruments as the Landsat 4 TM satellite. The TM sensor of the Landsat 5TM satellite is still working, while the MSS sensor data acquisition was suspendedin 1992. Landsat 5 has a sunsynchronous orbit of 98.2 ◦ inclination. It crosses theequator at about 9:45 a.m. local time. The orbit height above the Earths surfaceis 705 km. One orbit takes the satellite about 100 minutes. The TM band pixelsizefor the spectral bands 1 to 5 and the spectral band 7 is 30 meters by 30 meters. Thepixelsize for the spectral band 6 is 120 meters by 120 meters. The quantisation for allspectral bands of the Landsat 5 TM satellite is 8 bits. In table 3.1 the spectral rangeand the resolution of the Landsat 5 TM sensor are shown. Table 3.2 summarises21