{"action":"created","issue":{"url":"https://api.github.com/repos/terraref/reference-data/issues/51","repository_url":"https://api.github.com/repos/terraref/reference-data","labels_url":"https://api.github.com/repos/terraref/reference-data/issues/51/labels{/name}","comments_url":"https://api.github.com/repos/terraref/reference-data/issues/51/comments","events_url":"https://api.github.com/repos/terraref/reference-data/issues/51/events","html_url":"https://github.com/terraref/reference-data/issues/51","id":175841509,"number":51,"title":"Create custom spatial reference systems for PostGIS","user":{"login":"max-zilla","id":14166971,"avatar_url":"https://avatars.githubusercontent.com/u/14166971?v=3","gravatar_id":"","url":"https://api.github.com/users/max-zilla","html_url":"https://github.com/max-zilla","followers_url":"https://api.github.com/users/max-zilla/followers","following_url":"https://api.github.com/users/max-zilla/following{/other_user}","gists_url":"https://api.github.com/users/max-zilla/gists{/gist_id}","starred_url":"https://api.github.com/users/max-zilla/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/max-zilla/subscriptions","organizations_url":"https://api.github.com/users/max-zilla/orgs","repos_url":"https://api.github.com/users/max-zilla/repos","events_url":"https://api.github.com/users/max-zilla/events{/privacy}","received_events_url":"https://api.github.com/users/max-zilla/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":4,"created_at":"2016-09-08T19:26:49Z","updated_at":"2016-09-08T20:00:12Z","closed_at":null,"body":"@yanliu-chn talked today about creating 3 custom SRS's for this project that I didn't capture very well in my notes:\r\n- Arizona MAC coordinate system\r\n- USDA coordinate system\r\n- (0,0) inversion\r\n\r\nCould you say a tiny bit about these? I wanted to create an issue to capture that. For my own understanding, I found this:\r\nhttp://geeohspatial.blogspot.com/2013/03/custom-srss-in-postgis-and-qgis.html\r\n\r\n...where ultimately we might simply need to define our custom SRID in PostGIS with something like:\r\n```\r\nINSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 96703, 'sr-org', 6703, '+proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs', 'PROJCS[\"USA_Contiguous_Albers_Equal_Area_Conic_USGS_version\",GEOGCS[\"GCS_North_American_1983\",DATUM[\"D_North_American_1983\",SPHEROID[\"GRS_1980\",6378137.0,298.257222101]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Albers\"],PARAMETER[\"False_Easting\",0.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",-96.0],PARAMETER[\"Standard_Parallel_1\",29.5],PARAMETER[\"Standard_Parallel_2\",45.5],PARAMETER[\"Latitude_Of_Origin\",23.0],UNIT[\"Meter\",1.0]]');\r\n```\r\n\r\n@robkooper \r\nWe could then define columns in Clowder PostGIS for each of the custom SRIDs - a setup script could check for some custom definitions file in Clowder, insert those into PostGIS if found, and change how the datapoints/etc. tables are defined accordingly. The geog column (which is currently the only one) could still be SRID 4326 and that can always be present, but then we could also have geog_96703 or other SRIDs for project-specific SRS's.\r\n\r\nSo for Terra we might end up with geog, geog_999001, geog_999002, geog_999003 where the 99900x are our 3 SRIDs. Then we require data to be submitted in one of the 4 reference systems. If a new sensor emerges with a new one, we add a column for it.\r\n\r\nThis is mostly thinking out loud... maybe I'm way off."},"comment":{"url":"https://api.github.com/repos/terraref/reference-data/issues/comments/245721286","html_url":"https://github.com/terraref/reference-data/issues/51#issuecomment-245721286","issue_url":"https://api.github.com/repos/terraref/reference-data/issues/51","id":245721286,"user":{"login":"JeffWhiteAZ","id":4009094,"avatar_url":"https://avatars.githubusercontent.com/u/4009094?v=3","gravatar_id":"","url":"https://api.github.com/users/JeffWhiteAZ","html_url":"https://github.com/JeffWhiteAZ","followers_url":"https://api.github.com/users/JeffWhiteAZ/followers","following_url":"https://api.github.com/users/JeffWhiteAZ/following{/other_user}","gists_url":"https://api.github.com/users/JeffWhiteAZ/gists{/gist_id}","starred_url":"https://api.github.com/users/JeffWhiteAZ/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/JeffWhiteAZ/subscriptions","organizations_url":"https://api.github.com/users/JeffWhiteAZ/orgs","repos_url":"https://api.github.com/users/JeffWhiteAZ/repos","events_url":"https://api.github.com/users/JeffWhiteAZ/events{/privacy}","received_events_url":"https://api.github.com/users/JeffWhiteAZ/received_events","type":"User","site_admin":false},"created_at":"2016-09-08T20:00:12Z","updated_at":"2016-09-08T20:00:12Z","body":"I'm sorry. I misread the previous messages. My understanding:\r\n- \"USDA\" is based on a correctly located base station and hence is the most accurate and useful for long-term use. What we are really saying is that we're using standard geocoordinates (UTM referenced to a specific datum?). USDA ALARC's base station + rover is simply the best available source of RTK-corrected data so that is what was used to establish locations of the scanner coordinates.\r\n- Arizona MAC coordinate system is valuable for interfacing with data from MAC field equipment\r\n- Raw gantry with x positive west is standard output from Lemnatec, so is needed\r\n- Inversion of gantry coordinate with 0,0 in SW corner is much easier for people to interpret if they are not familiar with UTM\r\nIs that correct?\r\n"}}
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