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8

Using QGIS, you can use the SwapXY plugin. You can also do this with GDAL/OGR: https://trac.osgeo.org/gdal/wiki/FAQVector#HowdoIflipcoordinateswhentheyarenotintheexpectedorder


4

If it originally shows as "unknown" for CS how is it/how would I know that it is a PCS? Decimal degrees range from -180 to +180 west/east and 90 to -90 north/south, so the values you're seeing are definitely not decimal degrees. If there was no metadata provided with the contour data (and the agency isn't able to provide any information), you may ...


3

I am afraid that the answer is no: what you mean to do is correct but it will not work like this in ArcGIS with Near. From the help, you can read that : The distances calculated by this tool are in the unit of the coordinate system of the input features. If your input is in a geographic coordinate system and you want output distances to be ...


3

I have edited this answer to reflect the new information in the question. I am leaving the old solutions for anyone who might find the question in future searches but actually have those issues. As dklassen pointed out they may have been created in 21S even though they don't 'belong' there, in which case bringing them in/defining them as what they should ...


3

Below is a ToolValidator class (in its entirety so it will make sense) where I needed not only for input datasets to have a spatial reference defined, BUT the datum could only be either WGS84 or NAD83. If validation failed, they got little messages informing them of the issues. class ToolValidator: """Class for validating a tool's parameter values and ...


3

EPSG:24378 Kalianpur 1975 / India I should be the local CRS in the region you mentioned. The extent seems to fit to that: To get this picture using QGIS, create these text files: E N 73.4775 34.3629 and Easting Northing 3250193.00 1115573.00 3249214.00 1111220.00 Load each into QGIS as Delimited Text File, with blank as delimiter and setting CRS to ...


3

You are absolutely correct. From wikipedia's Mercator projection: scale factor = secant (latitude) = 1 / cosine (latitude) Generally, divide map distance by the scale factor to get globe distance. But what about "long" lines, at different latitudes, what scale factor to use? According to EF Burkholder, for short lines, just calculate one scale factor ...


1

Part of your error is in the tool you used. You may want to convert them (depends on what you're doing - it's more likely you'll want to go the other way and have your GPS points projected to your contour CS), but that's not what the Define Projection tool does. That tool is intended to be used when you know the projection the data is in, but it doesn't (no ...


1

In 2008, I usually do select SHAPE.STSrid from dbo.STATES (where SHAPE is the geometry column and dbo.states is the table name). It will give you SRID. Now you can run select * from sys.spatial_reference_systems where spatial_reference_id = 4326 However, as @Jay Cummins mentioned, it seems to have only geographic coordinate systems. Link to the ...


1

It seems you're overcomplicating the use of SRS flags. If you have source data from two spatial reference systems (SRSs): EPSG:4269 (Census data) and EPSG:3081 (Texas data), and your desired SRS (in PostGIS) is EPSG:4269 (same as Census data), then you'd use two variations of the ogr2ogr command. For the Texas data, specify source and target SRSs, so data ...


1

If you have Qgis, you can ask gdalsrsinfo in the OSGeo4w shell: gdalsrsinfo "+proj=tmerc +lat_0=0 +lon_0=-114 +k=0.9999 +x_0=0 +y _0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs" PROJ.4 : '+proj=tmerc +lat_0=0 +lon_0=-114 +k=0.9999 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs ' OGC WKT : PROJCS["unnamed", GEOGCS["GRS ...


1

I think the data is rather in meters in a projected local CRS. It might be necessary to add a high number constant to get the full coordinates needed for reprojection to WGS84. For India, a set of local coordinate systems has been established, see http://kanchu_deep.tripod.com/igintro.htm You have to know in which zone your data is collected. It might ...


1

There are some methods to calculate geodesic distances such as the haversine formula and Vincenty's formulae. These formulae are commonly used. The inverse Vincenty distance formula is the more accurate method to calculate the geodesic distance and is used in Google Maps, but it is slow.


1

No, if using the ArcGIS "Near" tool because, even if the coordinate system is geographic/geodetic, it does not calculate geodesic distances; it merely treats those geographic coordinates as though they were projected and thus gives results that cannot be compared across the US. Yes, if you correctly calculate geodesic distances using geographic ...


1

ok so COSINE is simply the ratio used to calculate the distance from 0° Longitude (i.e. the center of the shpere) to the tangent of the sphere at a given latitude. This site helped me understand the concept. http://www.mathsisfun.com/sine-cosine-tangent.html



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