All Products
Search
Document Center

ApsaraDB RDS:ST_RPCGeoreference

Last Updated:Mar 28, 2026

Returns the rational polynomial coefficient (RPC) parameters of a raster object as a JSON string. Returns null if the raster object contains no RPC information.

Syntax

text ST_RPCGeoreference(raster raster_obj)

Parameters

ParameterDescription
raster_objThe raster object.

Description

ST_RPCGeoreference returns a JSON string containing the RPC parameters that describe the spatial reference model of the raster object. The following table lists the fields in the returned JSON string.

FieldTypeDescription
lineOfffloatThe line offset.
sampOfffloatThe sampling offset.
latOfffloatThe latitude offset.
longOfffloatThe longitude offset.
heightOfffloatThe height offset.
lineScalefloatThe line ratio.
sampScalefloatThe sampling ratio.
latScalefloatThe latitude ratio.
longScalefloatThe longitude ratio.
heightScalefloatThe height ratio.
lineDenCoefffloat arrayThe number of coefficients for a line denominator. Valid values: 1 to 20.
lineNumCoefffloat arrayThe number of coefficients for a line numerator. Valid values: 1 to 20.
sampNumCoefffloat arrayThe number of coefficients for a sample numerator. Valid values: 1 to 20.
sampDenCoefffloat arrayThe number of coefficients for a sample denominator. Valid values: 1 to 20.
errBiasfloatThe root mean square (RMS) bias error in meters, calculated across all points on the horizontal axis of the image. Default value: -1.0.
errRandomfloatThe RMS random error in meters, calculated per point on the horizontal axis of the image. Default value: -1.0.

Example

SELECT ST_RPCGeoreference(raster_obj) FROM raster_table WHERE id = 1;

Output:

{"lineOff":12800.0,"sampOff":4008.0,"latOff":55.0203,"longOff":27.0478,"heightOff":179.0,"lineScale":12800.0,"sampScale":4008.0,"latScale":0.1238,"longScale":0.0685,"heightScale":300.0,"errBias":-1.0,"errRandom":-1.0,"lineDenCoeff":[1.0,-0.00050066513,-0.0014578309,0.0006037474,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0],"lineNumCoeff":[-0.002104832,-0.01642616,-1.027459,0.0041820025,-0.0019027952,0.000016143133,0.00047863558,-0.00021278669,0.0069588307,-0.0000022605722,-2.2259552e-7,-3.7469372e-7,0.00046486457,-1.8012888e-8,0.000051407583,0.00075661479,-5.4524409e-7,1.3940799e-7,-0.000018281596,2.4215581e-9],"sampDenCoeff":[1.0,-0.00050066513,-0.0014578309,0.00060374744,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0],"sampNumCoeff":[1.0,-0.00050066513,-0.0014578309,0.00060374744,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0]}