派生——派生子数据集驱动程序

司机简称

DERIVED

Driver built-in by default

This driver is built-in by default

This driver allows accessing subdatasets derived from a given dataset. Those derived datasets have the same projection reference, geo-transform and metadata than the original dataset, but derives new pixel values using gdal pixel functions.

可用功能

可用的派生数据集包括:

  • 振幅:输入波段像素的振幅

  • 相位:输入波段像素的相位

  • 实数:输入带像素的实数部分

  • IMAG:输入带像素的虚部

  • CONJ:输入带像素的共轭

  • 强度:输入波段像素的强度(平方振幅)

  • LOGAMPLITUDE:输入波段像素振幅的Log10

注:对于非复杂数据类型,只列出对数振幅。

一个典型的用途是直接访问任何复杂数据集的振幅、相位或对数振幅。

访问派生子数据集

派生子数据集存储在派生子数据集元数据域中,可以使用以下语法进行访问:

DERIVED_SUBDATASET:FUNCTION:dataset_name

其中函数是振幅、相位、实数、IMAG、CONJ、强度、对数振幅之一。为了确保数值精度,所有导出的子数据集频带将具有Float64或CFloat64精度(取决于所使用的函数)。

例如:

$ gdalinfo cint_sar.tif
Driver: GTiff/GeoTIFF
Files: cint_sar.tif
Size is 5, 6
Coordinate System is `'
GCP Projection =
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
GCP[  0]: Id=1, Info=
          (-1910.5,-7430.5) -> (297.507,16.368,0)
GCP[  1]: Id=2, Info=
          (588.5,-7430.5) -> (297.938,16.455,0)
GCP[  2]: Id=3, Info=
          (588.5,7363.5) -> (297.824,16.977,0)
GCP[  3]: Id=4, Info=
          (-1910.5,7363.5) -> (297.393,16.89,0)
Metadata:
  AREA_OR_POINT=Area
  CEOS_ACQUISITION_TIME=19970718024119087
  CEOS_ELLIPSOID=GEM6
  CEOS_INC_ANGLE=24.824
  CEOS_LINE_SPACING_METERS=3.9900000
  CEOS_LOGICAL_VOLUME_ID=0001667400297672
  CEOS_PIXEL_SPACING_METERS=7.9040000
  CEOS_PIXEL_TIME_DIR=INCREASE
  CEOS_PLATFORM_HEADING=347.339
  CEOS_PLATFORM_LATITUDE=16.213
  CEOS_PLATFORM_LONGITUDE=-65.311
  CEOS_PROCESSING_AGENCY=ESA
  CEOS_PROCESSING_COUNTRY=ITALY
  CEOS_PROCESSING_FACILITY=ES
  CEOS_SEMI_MAJOR=6378.1440000
  CEOS_SEMI_MINOR=6356.7590000
  CEOS_SENSOR_CLOCK_ANGLE=90.000
  CEOS_SOFTWARE_ID=ERS2-SLC-6.1
  CEOS_TRUE_HEADING=345.5885834
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0,    6.0)
Upper Right (    5.0,    0.0)
Lower Right (    5.0,    6.0)
Center      (    2.5,    3.0)
Band 1 Block=5x6 Type=CInt16, ColorInterp=Gray
$ gdalinfo DERIVED_SUBDATASET:LOGAMPLITUDE:cint_sar.tif
Driver: DERIVED/Derived datasets using VRT pixel functions
Files: cint_sar.tif
Size is 5, 6
Coordinate System is `'
GCP Projection =
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
GCP[  0]: Id=1, Info=
          (-1910.5,-7430.5) -> (297.507,16.368,0)
GCP[  1]: Id=2, Info=
          (588.5,-7430.5) -> (297.938,16.455,0)
GCP[  2]: Id=3, Info=
          (588.5,7363.5) -> (297.824,16.977,0)
GCP[  3]: Id=4, Info=
          (-1910.5,7363.5) -> (297.393,16.89,0)
Metadata:
  AREA_OR_POINT=Area
  CEOS_ACQUISITION_TIME=19970718024119087
  CEOS_ELLIPSOID=GEM6
  CEOS_INC_ANGLE=24.824
  CEOS_LINE_SPACING_METERS=3.9900000
  CEOS_LOGICAL_VOLUME_ID=0001667400297672
  CEOS_PIXEL_SPACING_METERS=7.9040000
  CEOS_PIXEL_TIME_DIR=INCREASE
  CEOS_PLATFORM_HEADING=347.339
  CEOS_PLATFORM_LATITUDE=16.213
  CEOS_PLATFORM_LONGITUDE=-65.311
  CEOS_PROCESSING_AGENCY=ESA
  CEOS_PROCESSING_COUNTRY=ITALY
  CEOS_PROCESSING_FACILITY=ES
  CEOS_SEMI_MAJOR=6378.1440000
  CEOS_SEMI_MINOR=6356.7590000
  CEOS_SENSOR_CLOCK_ANGLE=90.000
  CEOS_SOFTWARE_ID=ERS2-SLC-6.1
  CEOS_TRUE_HEADING=345.5885834
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0,    6.0)
Upper Right (    5.0,    0.0)
Lower Right (    5.0,    6.0)
Center      (    2.5,    3.0)
Band 1 Block=5x6 Type=Float64, ColorInterp=Undefined

列出可用的子数据集

在派生的子数据集元数据域中报告可用的子数据集。对于给定的数据集,只报告有意义的函数,这意味着只有当数据集至少有一个复杂的频带时,才会报告振幅、相位、实数、IMAG、CONJ和强度。尽管如此,即使没有报告,这些派生数据集仍然可以使用上述语法访问。

$ gdalinfo -mdd DERIVED_SUBDATASETS cint_sar.tif
Driver: GTiff/GeoTIFF
Files: cint_sar.tif
Size is 5, 6
Coordinate System is `'
GCP Projection =
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
GCP[  0]: Id=1, Info=
          (-1910.5,-7430.5) -> (297.507,16.368,0)
GCP[  1]: Id=2, Info=
          (588.5,-7430.5) -> (297.938,16.455,0)
GCP[  2]: Id=3, Info=
          (588.5,7363.5) -> (297.824,16.977,0)
GCP[  3]: Id=4, Info=
          (-1910.5,7363.5) -> (297.393,16.89,0)
Metadata:
  AREA_OR_POINT=Area
  CEOS_ACQUISITION_TIME=19970718024119087
  CEOS_ELLIPSOID=GEM6
  CEOS_INC_ANGLE=24.824
  CEOS_LINE_SPACING_METERS=3.9900000
  CEOS_LOGICAL_VOLUME_ID=0001667400297672
  CEOS_PIXEL_SPACING_METERS=7.9040000
  CEOS_PIXEL_TIME_DIR=INCREASE
  CEOS_PLATFORM_HEADING=347.339
  CEOS_PLATFORM_LATITUDE=16.213
  CEOS_PLATFORM_LONGITUDE=-65.311
  CEOS_PROCESSING_AGENCY=ESA
  CEOS_PROCESSING_COUNTRY=ITALY
  CEOS_PROCESSING_FACILITY=ES
  CEOS_SEMI_MAJOR=6378.1440000
  CEOS_SEMI_MINOR=6356.7590000
  CEOS_SENSOR_CLOCK_ANGLE=90.000
  CEOS_SOFTWARE_ID=ERS2-SLC-6.1
  CEOS_TRUE_HEADING=345.5885834
Metadata (DERIVED_SUBDATASETS):
  DERIVED_SUBDATASET_1_NAME=DERIVED_SUBDATASET:AMPLITUDE:cint_sar.tif
  DERIVED_SUBDATASET_1_DESC=Amplitude of input bands from cint_sar.tif
  DERIVED_SUBDATASET_2_NAME=DERIVED_SUBDATASET:PHASE:cint_sar.tif
  DERIVED_SUBDATASET_2_DESC=Phase of input bands from cint_sar.tif
  DERIVED_SUBDATASET_3_NAME=DERIVED_SUBDATASET:REAL:cint_sar.tif
  DERIVED_SUBDATASET_3_DESC=Real part of input bands from cint_sar.tif
  DERIVED_SUBDATASET_4_NAME=DERIVED_SUBDATASET:IMAG:cint_sar.tif
  DERIVED_SUBDATASET_4_DESC=Imaginary part of input bands from cint_sar.tif
  DERIVED_SUBDATASET_5_NAME=DERIVED_SUBDATASET:CONJ:cint_sar.tif
  DERIVED_SUBDATASET_5_DESC=Conjugate of input bands from cint_sar.tif
  DERIVED_SUBDATASET_6_NAME=DERIVED_SUBDATASET:INTENSITY:cint_sar.tif
  DERIVED_SUBDATASET_6_DESC=Intensity (squared amplitude) of input bands from cint_sar.tif
  DERIVED_SUBDATASET_7_NAME=DERIVED_SUBDATASET:LOGAMPLITUDE:cint_sar.tif
  DERIVED_SUBDATASET_7_DESC=log10 of amplitude of input bands from cint_sar.tif
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0,    6.0)
Upper Right (    5.0,    0.0)
Lower Right (    5.0,    6.0)
Center      (    2.5,    3.0)
Band 1 Block=5x6 Type=CInt16, ColorInterp=Gray

参见: