Data Format Interoperability--Key Formats

Most GIS and geomorphometry programs have their own internal format, which is designed for optimal storage and processing for the particular program.  Most programs can convert a number of other formats into their internal format, and can export to a number of other formats.

Three formats have the most versatility, and widest acceptance, for the three main classes of data.  Rasters have traditionally been the data used by geomorphometry, but the increasing availability of lidar data sets may drive algorithm development toward the raw point cloud instead of the derived grids. 

	Raster	Geotiff especially with the GDAL drivers.  Problems include: Tiling may cause issues Inconsistent handling of missing data
	Vector	Shapefile ESRI spec did not call for datum projection PRJ file not always present, and not always interpreted correctly
	Point cloud	LAS with LAZ compression
	Raster/Vector Mix	KML format Lacks a way to manipulate or search for data attributes.  Combines raster and vector data in a single file. Can be compresses as KMZ file Good distribution format to non-GIS users

With the ability to exchange data in common formats, users can use several programs to capitalize on the unique capabilities of each.

Some programs will require a separate import step, and write a new version of the program in their native format, while others will convert on the fly and keep the native version of the data set in memory.

Formats to watch:

• OGC Geopackage: supports raster (especially tiled data) and vector data; design had mobile devices as key motivating factor.  Apparently not yet a lot of data. GDAL is supposed to be able to import.

Formats to avoid:

• World files

Last revised 3/10/2018