Importing ASTER data

ASTER data are downloaded from https://earthdata.nasa.gov.

Step 1: Downloading the data

For geological work the complete range of 14 bands are usually required. The recommended files to download are AST_07XT (crosstalk-corrected SWIR and VNIR) and AST_05 (Surface Emissivity). Note that the SWIR sensor failed in April 2008 so only use data collected before this date.

When downloading the data be sure to select AST_07XT and AST_05 scenes with exactly the same date and time of collection. PyGMI will automatically link the VNIR, SWIR and TIR datasets collected at the same time.

Data can be saved in two formats, namely HDF or a ZIP file containing the bands as GeoTIFFs. Both files will have an accompanying MET file. Both of the formats will be delivered as ZIP files, one for the VNIR and SWIR data, and one for the TIR data.

ASTER file formats.

Move the VNIR, SWIR and TIR files (files on the right-hand side of above figure) to a single folder (Figure 214).

VNIR, SWIR and TIR files in a single folder.

Go to Import Satellite Data on the Remote Sensing menu and select any of the files (VNIR,SWIR or TIR), it will automatically look for the other files. If you don’t see 14 bands it means one of the files was collected at a different date and time.

ASTER data import.

The data can be saved to a standard raster format by right-clicking on the Import Satellite module and selecting Export Raster Data.

When loading multiple scenes, all the VNIR, SWIR and TIR files must be copied into a single folder. PyGMI will link the correct files with each other based on the collection time and date.