Navigation:  Frequently Asked Questions >

What is ODE’s relationship to ESRI’s ArcGIS and what are Shapefiles?

Previous pageReturn to chapter overviewNext page

Footprints can be exported from ODE in ESRI’s Shapefile format.  Shapefile format stores both the footprint location data as well as a table of product attributes including the instrument host, instrument, product type, dataset, product id, and a URL back to ODE’s Product Result page for that product.  Several GIS tools including ESRI’s ArcGIS, can read Shapefiles.

 

Since Shapefiles actually consist of several individual files, ODE provides the files in either Zip or Tar.Gz form.  Just download the Zip or Tar.Gz file, unzip, and open in your GIS tool.

 

Shapefiles, developed and regulated by ESRI, is a popular geospatial vector data format for GIS software. A shapefile is used to spatially describe geometries: points, polylines, and polygons. And it commonly refers to a collection of mandatory files with ".shp", ".shx", ".dbf", and other optional extensions such as ".prj", ".sbn" and ".sbx" on a common prefix name (e.g., "mars_mex_pfs_edrnom_northcenters_a.*"). The content of the mandatory and optional files are listed as follows

Mandatory files:
 * .shp — shape format; the feature geometry itself
 * .shx — shape index format; a positional index of the feature geometry to allow seeking forwards and backwards quickly
 * .dbf — attribute format; columnar attributes for each shape, in dBase III format
Optional files:
 * .prj — projection format; the coordinate system and projection information, a plain text file describing the projection using well-known text format
 * .sbn and * .sbx — a spatial index of the features
 * ..fbn and .fbx — a spatial index of the features for shapefiles that are read-only
 * .ain and .aih — an attribute index of the active fields in a table or a theme's attribute table
 * .ixs — a geocoding index for read-write shapefiles
 * .mxs — a geocoding index for read-write shapefiles (ODB format)
 * .atx — an attribute index for the .dbf file in the form of shapefile.columnname.atx (ArcGIS 8 and later)
 * .shp.xml — metadata in XML format
 * .cpg — used to specify the code page (only for .dbf) for identifying the character encoding to be used

The actual shapefile relates specifically to files with the ".shp" extension, however this file alone is incomplete for distribution, as the other supporting files are required. All files should be located in the same folder. And the shape file can be read by ESRI ArcGIS and ENVI. More information about shape file can be found in the following reference.

Environmental Systems Research Institute, Inc. (July, 1998). "ESRI Shapefile technical description". Url: http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf, Retrieved on 2009-01-30.