google-maps - 如何将 MTM(加拿大)坐标转换为纬度和经度

Question

我有一个 geojson 文件，指示蒙特利尔的一些兴趣点，但坐标不是纬度和经度，而是 MTM nad83，区域 8 中的 X、Y 坐标。

我想在谷歌地图中加载文件，但坐标需要转换..

我在互联网上搜索了很多，但我找到的只是一个能够转换它的网站:twcc.fr。在js源代码中，我没有找到任何东西，所以它可能是服务器端的。

有人知道坐标转换吗？

提前致谢

**编辑:** json 文件中的示例:

{"name":"json_sortie","type":"FeatureCollection"
,"features":[
{"type":"Feature","geometry":{"type":"Point","coordinates":[294079.844,5044618.5]},"properties":{"POTEAU_ID_POT":122476,"DATE_CONCEPTION_POT":20101216000000,"DESCRIPTION_REP":"Enlevé","DESCRIPTION_RTP":"2- Tige et manchon","X":294079.844,"Y":5044618.5,"ID_ARRONDISSEMENT":"25","TRC_ID":1110499}}
,{"type":"Feature","geometry":{"type":"Point","coordinates":[296910.375,5045914.5]},"properties":{"POTEAU_ID_POT":5766,"DATE_CONCEPTION_POT":20090707000000,"DESCRIPTION_REP":"Réel","DESCRIPTION_RTP":"3- Fût","X":296910.375,"Y":5045914.5,"ID_ARRONDISSEMENT":"25","TRC_ID":1090130}}
,{"type":"Feature","geometry":{"type":"Point","coordinates":[296908.938,5045915.5]},"properties":{"POTEAU_ID_POT":66342,"DATE_CONCEPTION_POT":20090707000000,"DESCRIPTION_REP":"Enlevé","DESCRIPTION_RTP":"1- Tige et base","X":296908.938,"Y":5045915.5,"ID_ARRONDISSEMENT":"25","TRC_ID":1090130}}
,{"type":"Feature","geometry":{"type":"Point","coordinates":[296481.188,5045804]},"properties":{"POTEAU_ID_POT":5030,"DATE_CONCEPTION_POT":20121108000000,"DESCRIPTION_REP":"Réel","DESCRIPTION_RTP":"1- Tige et base","X":296481.188,"Y":5045804,"ID_ARRONDISSEMENT":"25","TRC_ID":1100117}}

Answer 1

我找到了怎么做。如果您知道如何将 UTM 转换为 WGS84 纬度、经度，则可以转换 MTM。将 UTM 转换为 WGS84(纬度、经度)的方程为 here on Wikipedia .

MTM 类似于 UTM，但更精确。 UTM 的区域为 3°，而不是 6°。 scaleTM 是 0.9999，而不是 0.9996。东移误差为 304.8 公里(UTM 为 500 公里)。

要在 UTM 中获得引用子午线，您需要执行 refMeridian = Zone * 6° - 183°，但对于 MTM，我使用了与其引用子午线相对应的区域数组(我在互联网):

var zone_to_refmeridian =  // MTM zone to reference meridian
  [0, 53, 56, 58.5, 61.5, 64.5, 67.5, 70.5, 73.5,
   76.5, 79.5, 82.5, 81, 84, 87, 90, 93, 96, 99,
   102, 105, 108, 111, 114, 117, 120, 123, 126,
   129, 132, 135, 138, 141];

// For instance for Montreal city which is in zone 8:
zone_to_refmeridian[8] // for zone 8