# PDS -- Planetary Data System

PDS is a format used primarily by NASA to store and distribute solar, lunar and planetary imagery data. GDAL provides read-only access to PDS formatted imagery data.

PDS files often have the extension .img, sometimes with an associated .lbl (label) file. When a .lbl file exists it should be used as the dataset name rather than the .img file.

In addition to support for most PDS imagery configurations, this driver also reads georeferencing and coordinate system information as well as selected other header metadata.

Implementation of this driver was supported by the United States Geological Survey.

Due to ambiguities in the PDS specification, the georeferencing of some products is subtly or grossly incorrect. There are configuration variables which may be set for these products to correct the interpretation of the georeferencing. Some details are available in ticket #3940.

For example, the MOLA labels currently contain a one pixel offset. Once ticket #5941 is applied (should be available post 1.11.3), which corrects the PDS offset defaults, here is how you can correctly read in a MOLA label using the --config options in the PDS reader.

$ gdalinfo --config PDS_SampleProjOffset_Shift -0.5 --config PDS_LineProjOffset_Shift -0.5 mola.lbl

For LOLA global PDS files the center should be perfectly 0.0, 0.0 meters in Cartesian space. example conversion:

$ gdal_translate --config PDS_SampleProjOffset_Shift -0.5 --config PDS_LineProjOffset_Shift -0.5 mola.lbl out.tif

example conversion and applying offset and multiplier values as defined in some PDS labels:

$ gdal_translate -ot Float32 -unscale --config PDS_SampleProjOffset_Shift -0.5 --config PDS_LineProjOffset_Shift -0.5 mola.lbl out_32bit.tif

As a test, this lunar LOLA PDS label should be perfectly centered at 0.0, 0.0 meters in Cartesian space without any configuration options. Remember you will need a GDAL version post 1.11.3.

$ gdalinfo ldem_4.lbl

To test the --config keyword above, this Mars MOLA PDS label should be perfectly centered at 0.0, 0.0 meters in Cartesian space with the following configuration options. Remember you will need a GDAL version post 1.11.3.

$ gdalinfo --config PDS_SampleProjOffset_Shift -0.5 --config PDS_LineProjOffset_Shift -0.5 megt90n000cb.lbl

PDS is part of a family of related formats including ISIS2 and ISIS3.

## See Also:

- Implemented as `gdal/frmts/pds/pdsdataset.cpp`.
- NASA Planetary Data System
- GDAL ISIS2 Driver
- GDAL ISIS3 Driver