GDAL——命令使用专题——gdalsrsinfo命令
前言
GDAL(Geospatial Data Abstraction Library)是一个在X/MIT许可协议下的开源栅格空间数据转换库。它利用抽象数据模型来表达所支持的各种文件格式。它还有一系列命令行工具来进行数据转换和处理。
主要针对:ogrinfo命令、gdalinfo命令、gdalsrsinfo命令、gdallocationinfo命令、gdal_translate命令、gdaltransform命令 等。这一节讨论gdalsrsinfo命令。
gdalsrsinfo命令主要是用于获取空间坐标信息,如:WKT,PROJ.4 等格式。
软件环境:在安装Mapserver时集成安装。详见《MapServer Configuring with IIS》。
语法
Usage: gdalsrsinfo [options] srs_def srs_def may be the filename of a dataset supported by GDAL/OGR from which to extract SRS information OR any of the usual GDAL/OGR forms (complete WKT, PROJ.4, EPSG:n or a file containing the SRS)
#srs_def 表示空间坐标系统或坐标参考系统的文件,或代号 或数据集等。
#其需要被GDAL/OGR 支持
#如:WKT、PROJ.4,EPSG:n 或 包含 srs 信息的文件(如:esri的prj、shp文件等) Options: [--help-general] [-h] Show help and exit [-p] Pretty-print where applicable (e.g. WKT) #格式化输出 [-V] Validate SRS #打印验证的空间坐标信息 [-e] Search for EPSG number(s) corresponding to SRS #查询空间坐标信息对应的ESPG number [-o out_type] Output type { default, all, wkt_all, proj4, #指定输出数据类型,wkt,proj.4、wkt_esri都有自己的格式,按照指定的格式类型输出 wkt, wkt_simple, wkt_noct, wkt_esri, mapinfo, xml }
简单用例
#输出 ESPG:4326 的坐标信息
gdalsrsinfo "EPSG:4326" PROJ.4 : '+proj=longlat +datum=WGS84 +no_defs ' OGC WKT : GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4326"]]
#将prj文件转 proj.4格式 输出
gdalsrsinfo -o proj4 osr/data/lcc_esri.prj '+proj=lcc +lat_1=34.33333333333334 +lat_2=36.16666666666666 +lat_0=33.75 +lon_0=-79 +x_0=609601.22 +y_0=0 +datum=NAD83 +units=m +no_defs '
#输出tif文件的空间信息
gdalsrsinfo -o proj4 landsat.tif PROJ.4 : '+proj=utm +zone=19 +south +datum=WGS84 +units=m +no_defs '
#将 EPSG:32722 装换为 wkt 格式输出 并格式化
gdalsrsinfo -o wkt -p "EPSG:32722" PROJCS["WGS 84 / UTM zone 22S", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4326"]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",-51], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",500000], PARAMETER["false_northing",10000000], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AXIS["Easting",EAST], AXIS["Northing",NORTH], AUTHORITY["EPSG","32722"]]
#去掉 -p 参数后,其数据全部在一行里面
gdalsrsinfo -o wkt "EPSG:32722" PROJCS["WGS 84 / UTM zone 22S",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-51],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","32722"]]
#输出所有的wkt格式
gdalsrsinfo -o wkt_all "EPSG:4618" OGC WKT : GEOGCS["SAD69", DATUM["South_American_Datum_1969", SPHEROID["GRS 1967 Modified",6378160,298.25, AUTHORITY["EPSG","7050"]], TOWGS84[-57,1,-41,0,0,0,0], AUTHORITY["EPSG","6618"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4618"]] OGC WKT (simple) : GEOGCS["SAD69", DATUM["South_American_Datum_1969", SPHEROID["GRS 1967 Modified",6378160,298.25], TOWGS84[-57,1,-41,0,0,0,0]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]] OGC WKT (no CT) : GEOGCS["SAD69", DATUM["South_American_Datum_1969", SPHEROID["GRS 1967 Modified",6378160,298.25]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]] ESRI WKT : GEOGCS["SAD69", DATUM["D_South_American_1969", SPHEROID["GRS_1967_Truncated",6378160,298.25]], PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]]
名词解释
WKT:Well-known text,文本标记语言,用于在地图上表示矢量几何对象、空间对象的空间参考系统以及空间参考系统之间的转换。
EPSG:EPSG是一个与欧洲石油工业有联系的科学组织,由与石油勘探相关的应用大地测量、测量和制图方面的专家组成。《大地测量参数集》是地球椭球体、大地基准面、地理和投影坐标系、测量单位等资料的通用数据库。其实这里指的是“ESPG的通用数据库”
PROJ:PROJ是一个通用的坐标转换软件,它将地理空间坐标从一个坐标系转换为另一个坐标系。这包括地图投影和大地变换。