为什么 WorldView 3 图像的空间分辨率是这样的？

如何解决为什么 WorldView 3 图像的空间分辨率是这样的？

这张来自gdalinfo 20141030-wv03.tif的图片的输出是这样的：

Driver: GTiff/GeoTIFF
Files: 20141030-wv03.tif
Size is 16484,15253
Coordinate System is:
GEOGCRS["WGS 84",DATUM["World Geodetic System 1984",ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,2],AXIS["geodetic latitude (Lat)",north,ORDER[1],AXIS["geodetic longitude (Lon)",east,ORDER[2],ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
Origin = (113.959353776485997,23.091020758099145)
Pixel Size = (0.000002966620901,-0.000002966620901)
Metadata:
  AREA_OR_POINT=Area
  DataType=Generic
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  ( 113.9593538,23.0910208) (113d57'33.67"E,23d 5'27.67"N)
Lower Left  ( 113.9593538,23.0457709) (113d57'33.67"E,23d 2'44.78"N)
Upper Right ( 114.0082556,23.0910208) (114d 0'29.72"E,23d 5'27.67"N)
Lower Right ( 114.0082556,23.0457709) (114d 0'29.72"E,23d 2'44.78"N)
Center      ( 113.9838047,23.0683958) (113d59' 1.70"E,23d 4' 6.22"N)
Band 1 Block=128x128 Type=Byte,ColorInterp=Red
  NoData Value=256
Band 2 Block=128x128 Type=Byte,ColorInterp=Green
  NoData Value=256
Band 3 Block=128x128 Type=Byte,ColorInterp=Blue
  NoData Value=256

空间分辨率为(0.000002966620901,-0.000002966620901)，如何理解这个值？

我还检查了 WorldView 2 的另一张图片，输出是：

Driver: GTiff/GeoTIFF
Files: 20150708.tif
Size is 9984,10132
Coordinate System is:
PROJCRS["WGS 84 / UTM zone 50N",BASEGEOGCRS["WGS 84",4326]],CONVERSION["UTM zone 50N",METHOD["Transverse Mercator",9807]],PARAMETER["Latitude of natural origin",0.0174532925199433],8801]],PARAMETER["Longitude of natural origin",117,8802]],PARAMETER["Scale factor at natural origin",0.9996,SCALEUNIT["unity",1],8805]],PARAMETER["False easting",500000,8806]],PARAMETER["False northing",8807]]],CS[Cartesian,AXIS["(E)",1]],AXIS["(N)",USAGE[
        SCOPE["unknown"],AREA["World - N hemisphere - 114°E to 120°E - by country"],BBOX[0,114,84,120]],32650]]
Data axis to CRS axis mapping: 1,2
Origin = (291153.100000000034925,2705938.760000000242144)
Pixel Size = (0.510000000000000,-0.510000000000000)
Metadata:
  AREA_OR_POINT=Area
  TIFFTAG_XRESOLUTION=1
  TIFFTAG_YRESOLUTION=1
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (  291153.100,2705938.760) (114d56'22.85"E,24d27'10.88"N)
Lower Left  (  291153.100,2700771.440) (114d56'25.58"E,24d24'22.98"N)
Upper Right (  296244.940,2705938.760) (114d59'23.60"E,24d27'13.32"N)
Lower Right (  296244.940,2700771.440) (114d59'26.26"E,24d24'25.41"N)
Center      (  293699.020,2703355.100) (114d57'54.57"E,24d25'48.15"N)
Band 1 Block=9984x1 Type=Byte,ColorInterp=Red
Band 2 Block=9984x1 Type=Byte,ColorInterp=Green
Band 3 Block=9984x1 Type=Byte,ColorInterp=Blue

空间分辨率为(0.510000000000000,-0.510000000000000)。我如何理解它们之间的区别？谢谢。

解决方法

您的图像位于两个不同的坐标系中。

您的第二个文件 a[i] = i++ 位于 UTM 投影（准确地说是 UTM 50N）中，其地图单位为米 - 这就是像素分辨率为米 (0.51m) 的原因。

您的第一个文件 20150708.tif 位于地理坐标系中，广泛使用的 World Geodetic System 1984 (or WGS84) 以度为单位的地图单位，也为您提供（十进制）度的像素分辨率。在赤道上，0.00001 度大约为 1.11 meters，因此两个图像的分辨率可能相同。

有关 WGS84 与 UTM 的更多信息，this post on GIS stackexchange 可能会很有趣。