8

You could calculate the Geodesics. Saying you want to show the geodesic from A to B, you could first calculate the distance and azimuth from A to B (inverse Geodesic problem) and then calculate points from A to several points between A and B (direct Geodesic problem). I have added a simple script in Python using GeographicLib just outputting the stuff in ...


5

The principles in this blog post transfer over to general purpose PostGIS. http://blog.cartodb.com/jets-and-datelines/ Basically, use ST_Segmentize on geography, and a bit of magic to slice date-line crossing lines.


4

Local cartesian coordinate systems in CartConvert have their X axis towards the East, Y axis towards the North, and Z axis towards the "up" direction normal to the ellipsoid (this system is also called the ENU frame, for East North Up). Their orientation in space depends on the location of the chosen origin point. Therefore, the coordinates are not ...


3

Here's some example code using pyproj. Given a point in lat lon, it calculates new lat lon points given a distance in meters and an azimuth. The azimuth comes from the aspect ratio of the rectangle. from math import sqrt,atan,pi import pyproj geod = pyproj.Geod(ellps='WGS84') width = 10000. # m height = 20000. # m rect_diag = sqrt( width**2 + height**2 ) ...


3

To access a LAS file in C# it is best to use unsafe code, a dynamic cast as the same block of bytes (fixed to ensure the memory manager doesn't shift the bytes separate to the struct) to the struct means that changes can be made and the same block of memory written back to the file as bytes it can be done: [StructLayout(LayoutKind.Sequential, Pack = 1)] ...


2

Regarding azi1 vs azi2, azi1 is the direction measured at point 1 (your navigation aid) to point 2. azi2 is the direction measured at point 2 (your location) away from point 1. (If you want the direction to point 1, add ±180° to azi2.) Which azimuth you require will depend on what problem you're trying to solve. The direction is relative to ...


1

Gotcha !! The geographiclib-1.20.tar.gz package needs to be unzipped , so that there's a folder called geographiclib-1.20 is created with a file setup.py inside it. Run OsGeo4w Shell as administrator and use the cd to go the geographiclib-1.20 folder. Now type the command python setup.py install that's it. This will install the library in the correct folder ...


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