# Questions tagged [projection-mathematics]

The tag has no usage guidance.

12 questions
Filter by
Sorted by
Tagged with
31 views

### Web Mercator square and not 1x2?

I can not understand why Web Mercator projection is strictly square. In my mention: We have a planet as a sphere. We have 360 degrees of longitude and only 180 degrees of latitude. That means if we ...
26 views

### How to check for PostGIS Function Support Matrix for new custom EPSG imported from EPSG site

I need a support for CRS that was not available in PostGIS 2.5 so I looked up into the EPSG site they had simple easy straight forward insert query to add EPSG so I did that now how do I check or know ...
334 views

### Whats the name of this projection?

a) Whats the name of this projection? Source:http://www.viewsoftheworld.net/?p=5737 b) Is it possible tu use this projection in qgis?
39 views

### Calculate Coordinates on the Beeline between two Coordinates on a Spheroid/Ellipsoid (Earth)

I have two coordinates of locations on the earth and want to calculate points in between these two coordinates on the Beeline, for example the coordinate in the middle or at 10%. I am able to do this ...
41 views

### Is there a difference in using Haversine distance vs re-projecting coordinate frame?

I have a GeoTIFF raster file in the EPSG 4326 (WGS 84) geographic coordinate system. I want to crop a 20 km x 20 km square around a particular (lat, long) coordinate, and save that as a new raster. ...
88 views

### Procedure of transforming coordinates?

I'm trying to understand the math behind this transformation. I should note that I've been able to perform the transformation using GeoPandas, but I'd like to understand what is going on under the ...
16 views

### Transformation from Sphere_Natural_Earth to WGS1984

I have a set of files that are stored in Tom Patterson's Natural Earth Projection, and I would like to convert them to WGS1984. This will require a transformation, but I can't locate one and don't ...
23 views

### Correlation between varying bearings

Problem: The Bearing of point B from point A on one datum and projection varies from that on another datum and projection. Can a consistent correlation be established for the variation in the Bearings?...
244 views

### Projecting points on line and calculating distance from line start

I have a vector layer with a number of points which correspond to magnetic targets axis retrieved from AutoCAD The task is to project the points on the axis and then calculate the distance of each ...
67 views

### What parameters do azimuthal and transverse cylindrical projection in secant case have as proj4 string

conical equal-area projection, secant case has e.g. +proj=aea +lat_1=... +lat_2=... +lon_0=... +lat_0=... +x_0=... +y_0=... etc... I would ask if there is such thing, for transverse cylindrical ...