Geopositioning Level Codelist

Geopositioning Level Codelist

The value domain of Geopositioning Level Codelist is defined in the following table. It also corresponds to Product Preprocessing Level, as specified by some major imagery data vendors.

#	Code	English Name	Definition	Source
1	ungeoreferenced	Ungeoreferenced	No geographic location information is supplied. Examples: sketch or photo.
2	georeferenceable	Georeferenceable	Available with external geographic location information. Examples: "raw" image with auxiliary data like control points and/or sensor (geometric) model parameters.
3	l1a	GeoreferenceableL1A	- (for optical) Level 1A data have been corrected for detector radiometric variations within the sensor. Note: This processing level is the closest to the natural image acquired by the sensor, aimed at restoring perfect collection radiometric conditions. However, internal geometric distortion due to sensor persists within the image. - (for SAR) L1A or Single-look Complex Slant (SCS) products in slant range and zero Doppler projection.
4	l1b	GeoreferenceableL1B	- (for optical) Level 1B data have been corrected for predictable and measurable systematic distortions in the geometry of the imagery such as mis-aligned scan lines and non-uniform pixel sizes. (include same radiometric correction as L1A). Note: this level is also called “Primary”. This processing level is the closest to the natural image acquired by the sensor, aimed at restoring perfect collection conditions: the sensor is placed in rectilinear geometry, and the image is clear of all radiometric distortion. - (for SAR), Detected Ground Multilook (MDG) products, radiometrically equalized and in ground range/azimuth projection.
5	georectified	Georectified	Geocoded to include geographic location information in a given ellipsoid or datum. Examples: GeoTIFF image, terrain elevation model.
6	georectified1C	Georectified1C	(for SAR only) For CSK, Geocoded Ellipsoid Corrected (GEC) products: geo-located on the reference ellipsoid and represented in a uniform pre-selected cartographic presentation.
7	georectified2A	Georectified2A	(for optical) Radiometric correction identical to that of level 1A, geometrical correction in a standard cartographic projection (UTM WGS84 by default), not tied to ground control points, at a given height (usually estimated average height on the area covered by image). Note: This product level is commonly called “Ortho ready” product.
8	georectified2B	Georectified2B	(for optical) In addition to above level 2A, use of ground control points in geometric correction.
9	orthorectified	Orthorectified	Georectified and corrected for positional displacement with respect to the surface of the earth using a Digital Terrain Model. Examples: orthophoto. Note: called Level 3 by some vendors. For SAR, this correspond to Level1D products (e.g. for CSK).
10	trueOrthorectified	True orthorectified	Orthorectified and corrected for positional displacement with respect to the geometric properties of the features, generally using a Digital Surface Model. Examples: an ortho image where pixels corresponding to bridges or buildings have been corrected to take into account the difference of elevation with the ground.