I would like to know how you are creating the subset and exporting.  It should be no problem to export your data to GRID, TIFF, Imagine or other formats that ArcGIS can read.  I would not use ArcView raster bil since these have limited projection support when exporting in ENVI.  What do you mean by it not being 'viewable in Arc'?  It may be that you need to calculate statistics for the data since MODIS is often in a floating point data type.  You would do this in Arc under "Symbology" by applying a stretch to the data. However, if you are using ArcGIS 9.3, there is no need to convert your data to another format.  You should be able to open an ENVI format file (.dat or .img) natively in ArcGIS 9.3 and it should recognize the projection.  If you are subsetting your data by an ROI, then the data should already be in ENVI format, so no conversion is necessary.

Hi: Sorry fer my delayed reply. I tried your recommendations without success. I am going to explain the procedure in more detail. 1. Downloaded L3 MODIS K490 images(4Km). 2. Open  it in ENVI 4.4, it is an HDF dataset 3. Use a ROI to make a spatial subset of the global image. Load the Image. Save Image as (tried: ENVI, ERDAS, GEOTIFF, etc.) 4. Open ArcMap 9.3. Load image (warning of unknown spatial reference appears). Load shapefile (data in State PLane NAD 83 or I use another shapefile WGS 1984 projection). Dont see the shapefile so I use Full Extent. I notice the image is far from my shapefile and it is larger in scale. 5. Use build statistics to the image. Define projection to Geographic WGS-84 (Still no overlap of the image with my shapefile. Reload a another image, define the projection to NAD 83 StatePlane FIPS 5200 PR_USVI, no success. 6. I tried this procedure with all xported formats without success. I noticed that probably is a problem with the extent or tie points of trhe coordinate system. In ENVI, when I tried to edit the Map Info in the header file it reads (WGS-84) in the Map Coordinate of Tie Point area. It also has 2 open spaces to put the coordinates of tie points (dont know what number to put in there). Also the pixel size and rotation is empty. Please advice so what procedure might help with this. Thanks William

Yes, I have the similar questions about the ENVI data importing to Acgis, something sonds wrong. when you saved the .img to .bll, there image losed all of head information. project, coordinations, as well as classification data. now i am searching new methods to solving these problems.