WKT
WKT是坐标系统的描述性文字，与SRID一一对应，常用于支持空间数据的数据库中描述空间参考信息，其英文定义如下所示。
Well Known Text :A WKT string for a spatial reference system describes the datum, geoid, coordinate system, and map projection of the spatial objects.
SRID
SRID是坐标参考系统的唯一标识，其英文定义如下：
A Spatial Reference System Identifier (SRID) is a unique value used to unambiguously identify projected, unprojected, and local spatial coordinate system definitions. These coordinate systems form the heart of all GIS applications.
WKID
WKID是Well-known ID的缩写，常用语Arcgis二次开发中。表示不同空间参考所对应的ID，例如WKID=4214表示GCS_Beijing_1954这种空间参考，4326代表WGS 84投影。我们常用到的、与中国相关的只有一百多个坐标参考，具体如下表所示：
Geographic Coordinate System 地理坐标
WKID | 描述 | 4214 GCS_Beijing_1954 4326 GCS_WGS_1984 4490 GCS_China_Geodetic_Coordinate_System_2000 4555 GCS_New_Beijing 4610 GCS_Xian_1980Projected Coordinate System 投影坐标
WKID | 描述 | 2327 Xian_1980_GK_Zone_13 2328 Xian_1980_GK_Zone_14 2329 Xian_1980_GK_Zone_15 2330 Xian_1980_GK_Zone_16 2331 Xian_1980_GK_Zone_17 2332 Xian_1980_GK_Zone_18 2333 Xian_1980_GK_Zone_19 2334 Xian_1980_GK_Zone_20 2335 Xian_1980_GK_Zone_21 2336 Xian_1980_GK_Zone_22 2337 Xian_1980_GK_Zone_23 2338 Xian_1980_GK_CM_75E 2339 Xian_1980_GK_CM_81E 2340 Xian_1980_GK_CM_87E 2341 Xian_1980_GK_CM_93E 2342 Xian_1980_GK_CM_99E 2343 Xian_1980_GK_CM_105E 2344 Xian_1980_GK_CM_111E 2345 Xian_1980_GK_CM_117E 2346 Xian_1980_GK_CM_123E 2347 Xian_1980_GK_CM_129E 2348 Xian_1980_GK_CM_135E 2349 Xian_1980_3_Degree_GK_Zone_25 2350 Xian_1980_3_Degree_GK_Zone_26 2351 Xian_1980_3_Degree_GK_Zone_27 2352 Xian_1980_3_Degree_GK_Zone_28 2353 Xian_1980_3_Degree_GK_Zone_29 2354 Xian_1980_3_Degree_GK_Zone_30 2355 Xian_1980_3_Degree_GK_Zone_31 2356 Xian_1980_3_Degree_GK_Zone_32 2357 Xian_1980_3_Degree_GK_Zone_33 2358 Xian_1980_3_Degree_GK_Zone_34 2359 Xian_1980_3_Degree_GK_Zone_35 2360 Xian_1980_3_Degree_GK_Zone_36 2361 Xian_1980_3_Degree_GK_Zone_37 2362 Xian_1980_3_Degree_GK_Zone_38 2363 Xian_1980_3_Degree_GK_Zone_39 2364 Xian_1980_3_Degree_GK_Zone_40 2365 Xian_1980_3_Degree_GK_Zone_41 2366 Xian_1980_3_Degree_GK_Zone_42 2367 Xian_1980_3_Degree_GK_Zone_43 2368 Xian_1980_3_Degree_GK_Zone_44 2369 Xian_1980_3_Degree_GK_Zone_45 2370 Xian_1980_3_Degree_GK_CM_75E 2371 Xian_1980_3_Degree_GK_CM_78E 2372 Xian_1980_3_Degree_GK_CM_81E 2373 Xian_1980_3_Degree_GK_CM_84E 2374 Xian_1980_3_Degree_GK_CM_87E 2375 Xian_1980_3_Degree_GK_CM_90E 2376 Xian_1980_3_Degree_GK_CM_93E 2377 Xian_1980_3_Degree_GK_CM_96E 2378 Xian_1980_3_Degree_GK_CM_99E 2379 Xian_1980_3_Degree_GK_CM_102E 2380 Xian_1980_3_Degree_GK_CM_105E 2381 Xian_1980_3_Degree_GK_CM_108E 2382 Xian_1980_3_Degree_GK_CM_111E 2383 Xian_1980_3_Degree_GK_CM_114E 2384 Xian_1980_3_Degree_GK_CM_117E 2385 Xian_1980_3_Degree_GK_CM_120E 2386 Xian_1980_3_Degree_GK_CM_123E 2387 Xian_1980_3_Degree_GK_CM_126E 2388 Xian_1980_3_Degree_GK_CM_129E 2389 Xian_1980_3_Degree_GK_CM_132E 2390 Xian_1980_3_Degree_GK_CM_135E 2401 Beijing_1954_3_Degree_GK_Zone_25 2402 Beijing_1954_3_Degree_GK_Zone_26 2403 Beijing_1954_3_Degree_GK_Zone_27 2404 Beijing_1954_3_Degree_GK_Zone_28 2405 Beijing_1954_3_Degree_GK_Zone_29 2406 Beijing_1954_3_Degree_GK_Zone_30 2407 Beijing_1954_3_Degree_GK_Zone_31 2408 Beijing_1954_3_Degree_GK_Zone_32 2409 Beijing_1954_3_Degree_GK_Zone_33 2410 Beijing_1954_3_Degree_GK_Zone_34 2411 Beijing_1954_3_Degree_GK_Zone_35 2412 Beijing_1954_3_Degree_GK_Zone_36 2413 Beijing_1954_3_Degree_GK_Zone_37 2414 Beijing_1954_3_Degree_GK_Zone_38 2415 Beijing_1954_3_Degree_GK_Zone_39 2416 Beijing_1954_3_Degree_GK_Zone_40 2417 Beijing_1954_3_Degree_GK_Zone_41 2418 Beijing_1954_3_Degree_GK_Zone_42 2419 Beijing_1954_3_Degree_GK_Zone_43 2420 Beijing_1954_3_Degree_GK_Zone_44 2421 Beijing_1954_3_Degree_GK_Zone_45 2422 Beijing_1954_3_Degree_GK_CM_75E 2423 Beijing_1954_3_Degree_GK_CM_78E 2424 Beijing_1954_3_Degree_GK_CM_81E 2425 Beijing_1954_3_Degree_GK_CM_84E 2426 Beijing_1954_3_Degree_GK_CM_87E 2427 Beijing_1954_3_Degree_GK_CM_90E 2428 Beijing_1954_3_Degree_GK_CM_93E 2429 Beijing_1954_3_Degree_GK_CM_96E 2430 Beijing_1954_3_Degree_GK_CM_99E 2431 Beijing_1954_3_Degree_GK_CM_102E 2432 Beijing_1954_3_Degree_GK_CM_105E 2433 Beijing_1954_3_Degree_GK_CM_108E 2434 Beijing_1954_3_Degree_GK_CM_111E 2435 Beijing_1954_3_Degree_GK_CM_114E 2436 Beijing_1954_3_Degree_GK_CM_117E 2437 Beijing_1954_3_Degree_GK_CM_120E 2438 Beijing_1954_3_Degree_GK_CM_123E 2439 Beijing_1954_3_Degree_GK_CM_126E 2440 Beijing_1954_3_Degree_GK_CM_129E 2441 Beijing_1954_3_Degree_GK_CM_132E 2442 Beijing_1954_3_Degree_GK_CM_135E 21413 Beijing_1954_GK_Zone_13 21414 Beijing_1954_GK_Zone_14 21415 Beijing_1954_GK_Zone_15 21416 Beijing_1954_GK_Zone_16 21417 Beijing_1954_GK_Zone_17 21418 Beijing_1954_GK_Zone_18 21419 Beijing_1954_GK_Zone_19 21420 Beijing_1954_GK_Zone_20 21421 Beijing_1954_GK_Zone_21 21422 Beijing_1954_GK_Zone_22 21423 Beijing_1954_GK_Zone_23 21473 Beijing_1954_GK_Zone_13N 21474 Beijing_1954_GK_Zone_14N 21475 Beijing_1954_GK_Zone_15N 21476 Beijing_1954_GK_Zone_16N 21477 Beijing_1954_GK_Zone_17N 21478 Beijing_1954_GK_Zone_18N 21479 Beijing_1954_GK_Zone_19N 21480 Beijing_1954_GK_Zone_20N 21481 Beijing_1954_GK_Zone_21N 21482 Beijing_1954_GK_Zone_22N 21483 Beijing_1954_GK_Zone_23N 3395 WGS_1984_World_Mercator参考
- Projected Coordinate Systems
- Geographic Coordinate Systems
- SRS SRID等介绍
