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1d
comment Obtaining Cartesian X & Y values from Lat/Long
You could create a custom azimuthal equidistant projection with the center at the runway endpoint. Project all obstacles and the runway endpoint into it. Now you can calculate the distances between them.
1d
comment Openlayers Reprojection from 4326 to 3395 is wrong?
-90 (or +90) goes to infinity in a Mercator projection. In Esri projection engine, the first two values you got are what I get for (-180, -79) so it could be the extent is getting wildly distorted. The last value is PI/2 in radians and value 3 is darn close to 2*PI.
1d
comment Which PCS to use with WGS 1984 datum?
Even "equidistant" projections only maintain distances in certain directions, otherwise there's some distortion. Your choice may depend on what accuracy you expect. A UTM zone, for instance has distortion no worse than 1 part in 2500 (aka 1 m in 2.5 km).
2d
comment Change the actual coordinates in a shapefile (QGIS)
What might have happened is that it was in a Texas state plane zone, but someone unprojected to lat-lon but using the wrong zone. Except that should have offset the data east-west too. What county?
2d
comment Find distance from points along lines
@giscard78 I thought of that. Any road that turns will hit 1 mile in distance before a radial road will, so you will only have "false positives" if you just buffer 1 mile.
2d
reviewed Close how to fill missing data in topographic wetness index map
2d
comment Find distance from points along lines
Buffer the schools by 1 mile. Use those buffers to select the roads/lines within the buffers (might have to extract the data). Now buffer the lines by 20 ft.
Apr
27
reviewed Close ArcGIS 10.3 modelbuilder works in edit mode but not in “casual mode”?
Apr
27
reviewed Leave Closed Clip rasters to matching polygons
Apr
27
reviewed Leave Closed Why does QGIS spontaneously corrupt shapefile data?
Apr
27
reviewed Reopen Select by frequency
Apr
27
comment Coordinate points not lining up with a preexisting map on QGIS
If the CSV data is lat/lon (aka around x~ -82 and y ~ 26), set the coordinate reference system to 4269 (NAD83), not 2237. You have to get the data added in its "native" coordinate reference system before you can change it.
Apr
26
comment How to get WKT for various Spatial Reference Systems?
These are also "Esri" WKT versions. We have some quirky names and parameters that may not be understood by other software packages. Note: I work at Esri on coordinate systems, etc.
Apr
26
answered Default transformation for a EPSG CRS
Apr
26
revised NTv2 inverse transformation calculation process
wrote a little bit about ntv2 method
Apr
26
comment NTv2 inverse transformation calculation process
You have to use an iterative process (that uses the forward transformation as well) to find the values. You might look at the PROJ.4 source code as I believe it supports NTv2 files (or other datum transformation files).
Apr
22
reviewed Reject what can I use to export my maps to .gws format
Apr
22
comment GCS_Clarke_1880 transformation to GCS_WGS_1984 in ArcGIS 10.3.1
No, there aren't any Clarke 1880 transformations. There are heaps of GeoCRS (datum) transformations for GeoCRS that are based on Clarke 1880. What's the actual GeoCRS or datum for your data? What location does it represent?
Apr
22
comment GCS_Clarke_1880 transformation to GCS_WGS_1984 in ArcGIS 10.3.1
OP please read. Related, if not a duplicate: gis.stackexchange.com/questions/88415/…
Apr
22
revised Are perpendicular lines still perpendicular after converting from UTM zone 15 to 16 (or between two neighboring zones)?
added transverse