获取Raster对象的RPC（Rational Polynomial Coefficients）相关信息。如果Raster对象具备RPC信息，则返回一个JSON格式的字符串；如果不具备RPC信息，则返回NULL。

语法

text ST_RPCGeoreference(raster raster_obj)

参数

参数名称 描述
raster_obj Raster对象。

描述

ST_RPCGeoreference函数返回的RPC参数是基于JSON格式的字符串，描述了RPC空间的参考信息。支持的参数如下：

参数名称 描述 类型
lineOff 线偏移 float
sampOff 采样偏移 float
latOff 纬度偏移 float
longOff 经度偏移 float
heightOff 高程偏移 float
lineScale 线比例 float
sampScale 采样比例 float
latScale 纬度比例 float
longScale 经度比例 float
heightScale 高程比例 float
lineDenCoeff 线分母系数（20个） float array
lineNumCoeff 线分子系数（20个） float array
sampNumCoeff 采样分子系数（20个） float array
sampDenCoeff 采样分母系数（20个） float array
errBias 错误误差。以米为单位的图像中所有点的水平轴的均方根偏差误差，未知时为-1.0。 float
errRandom 随机误差。以米为单位的图像中每个点每水平轴的均方根随机误差，未知时为-1.0。 float

示例

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

__________________________________
 {"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.
.4,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0],"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-8,0.0.
.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]}