Use Georeference Data to georeference ASTER Level 1A data based on header information. ENVI performs a precision geocoding of the ASTER image using a complete geometry model of the earth and satellite orbit.

1. Open an ASTER HDF file by selecting File > Open from the menu bar.
2. Select Geometric Correction > Georeference by Sensor > Georeference ASTER from the Toolbox. The Input ASTER Image dialog appears.
3. Select an ASTER Level 1A image file.
4. Click OK. The Georeference ASTER Data dialog appears.
5. Select the desired output map projection by selecting a projection type from the list. By default, a UTM map projection is selected based on header information.
6. Enter the Number of Warp Points to use for X and Y. You may select a number of warp points up to the number of samples and lines in your image. If you select fewer warp points, they will be evenly spaced throughout the image.

Note: Using a large number of warp points will increase the processing time considerably.

7. If desired, specify to save the warp points to a GCP file, by entering or choosing an output filename.
8. Click OK. The Registration Parameters dialog appears.
9. Select the warping and resampling methods and change the output dimensions, if desired. The triangulation method is recommended to produce the most accurate results; however, that method is much slower than polynomial warping.
10. Enter or choose an output filename.
11. Click OK.