How to convert ASTER EOS-HDF imagery to IMG in ERDAS Imagine 8.7
Imagery from the ASTER instrument on the Terra platform is described at the JPL website. This description text was copied from p.24 of the following PDF file http://edcdaac.usgs.gov/aster/ASTER_GeoRef_FINAL.pdf
ERDAS Imagine 8.5 (Leica Geosystems)
The ERDAS Imagine suite of image processing software also handles the importing and geo-referencing of ASTER data sets. With Imagine 8.5, you need to get the ASTER EOS HDF Importer upgrade patch. This is standard in Imagine 8.6 and 8.7. If you are not familiar with the Imagine suite, visit: http://www.gis.leica-geosystems.com/Products/product_details.asp?product...
The following steps outline the process of importing an ASTER level-1B data set into Imagine:
1. Import the ASTER image with first-order transformation correction. Import > ASTER EOS HDF Format Importer > Correction > Correction Parameters • Initiate the Import module from the main list of modules
- Choose ASTER EOS-HDF Format as the file type and provide the input and output file names
- Select Correction (from the ASTER EOS HDF Format Importer dialog box), and check the Write Transform to Image box, with default Transformation Order of 1 to import the ASTER HDF file
- Assuming your data set has the full complement of VNIR, SWIR and TIR bands, you start with the VNIR bands. To import the SWIR and TIR bands, click on Next Image on the ASTER EOS HDF Format Importer dialog with the Correction option.
- The output image will be in Lat/Lon geographic coordinate system
You can view key attributes from the embedded HDF metadata by invoking ImageInfo from your Viewer, and selecting HDFGlobalAttributes (the fifth tab from the left)
2. Re-project the ASTER image using the DataPrep module. DataPrep > Reproject Images …> Reproject Images
- Initiate the DataPrep module from the main list of modules
- Select Reproject Images …, and provide input file and output image name or instance:
- Specify the output projection name and related details. o Projection name: UTM o Datum: WGS84 o UTM Zone Number: … o Output image pixel size (X,Y), units, & re-sampling method: 15m, 15m, Cubic Convolution …
3. The output is a north-up geo-referenced image. Figure 3 depicts a path-oriented versus a north-up image of the ASTER scene. If you so desire, save the output imagine image file to an alternative format with the Export module Export > Input > Output See the PDF pages 24-27 for screen shots of the menu commands.
| Satellite | Sensor | Band #s | Spectral Range | Scene Size | Pixel Res |
| ASTER | VNIR | 1, 2, 3n, 3b | 0.52 - 0.86 µm | 120 X 150 km | 15 meter |
| SWIR | 4-9 | 1.600 - 2.430 µm | 30 meter | ||
| TIR | 10-14 | 8.125 - 11.65 µm | 90 meter |
ASTER Viewing in Imagine
ASTER images load into the viewer in the top-left corner which is black due to the flight path angle. Scroll over to see the imagery. Also, if Band 3b is showing then a stereoscopic image will appear in your raster viewer. Raster > Band Combinations… to 3,2,1 will show only the nadir bands.
Imagery formats for GIS use
ArcGIS can read/write IMG format, and IMG is fast loading and it can contain many bands. GeoTIFF is a more versatile format as it can be read by most graphics programs and these images can be LZW compressed (see this post), however TIFF files are limited to 3 bands.