asterdataelevationnasa
In October 2011, NASA released the new ASTER GDEM global dataset (30m) and I have been wanting to get my hands on it. The only problem is that it takes forever to download and I do not feel like drawing tiny little boxes for the entire world.
Is there are any place I can download the whole thing from?
It is possible to import the SSURGO database into PostgreSQL, it is just not terribly easy. As answered in response to your other question, the SSURGO data can be downloaded by state. The information for some states (e.g., CA) will be too big and will need to be downloaded by county; multiple counties can be selected. Once the downloaded information is extracted from its archive, the spatial data are a collection of shapefiles and the tabular data are a collection of flat ASCII files (fields separated by '|').
The SSURGO metadata explains the relationships of tables (Data Model Diagram and Relations Report), table fields and their respective data type (Tables and Columns Report), and detailed column descriptions (Table Columns Description Report). Using this information it is possible to create the appropriate tables and import both the spatial and tabular data. I was able to import the mupolygon (polygon shapefile), mapunit, component, and coecoclass tables for the western US into PostgreSQL. SQL script for creating the above tables, bash script (rudimentary) for iterating over the downloaded data and importing into PostgreSQL, and SQL script for cleaning up the import.
ASTER scenes are not captured in a regular, repeating grid like the path/row system of Landsat. Instead, they are more scattered due to the much narrower swath (only 60 km versus 180 km for Landsat), off-nadir capture, and imagery tasking. You can see the scene boundaries in GLOVIS:
The listing of ASTER repositories has a number of other locations where you can search for scenes. I've used NASA REVERB since it's the only repository (as of a few years ago) that offered level 2 data to NASA-approved users. If you really want to have an offline directory of all ASTER scenes, you would probably have to crawl through the ASTER data pool at LPDAAC and create geometries in a shapefile/geodatabase based on the bounding box coordinates in the XML metadata files:
Best Answer
My suggestions would be to utilize reverb at http://reverb.echo.nasa.gov/reverb/. First register if you have not already done so. In the search box type ASTER GDEM and Select Dataset --- note if you want a particular area this is the point where you select the box range in the map window to the left (very useful feature!).
Select "Search for Granules"
Now begins the tedious part where there are over 22,000 ASTER GDEM tiles that cover the globe however, the website only list 400 per page where there is an 'Add All on Page' button but no Add All option (i.e. 50 + pages to go through + load time).
Press the View Items in Cart (Shopping Cart), press the 'ALL' button that will pop up a new message 'All Items on Page Selected. Select All n Items in Cart'. Click on that link. At the bottom of the page select 'Order Selected' (no direct download is available).
Follow the appropriate steps including your order details (its free no worries) and on the following page select the 'Order Option - Not Set and Required' button to state the reason for the download (remember to use the apply to all function).
You will then receive an email entitled CM SHARED with directions for ftp pull on your selected data. From my limited experience, this usually takes approximatley one working day. Essentially the ftp and pull directory to connect will look like:
This provides really fast download (unlike some other ftp sites Global Land Cover Facility) especially comming from Europe (5mb/s).
Sorry for the long answer to a rather simple procedure but as I write this I am actually downloading ASTER GDEMv2 data myself for the entire continous USA. Note ASTER GDEMv2 is not void filled (although improvements have been made), unlike others like SRTM V4.1 from http://srtm.csi.cgiar.org/ at 90m resolution.