Spheric/LX

HPLX Palmtop and DOS version

Spheric does spherical geometry calculations on the Earth's surface.

Enter two points (or a whole series of them) and have the distance (or the cumulative distance) computed and expressed in units of your liking: miles, nautical miles, or kilometers. Define a great arc (the shortest line between two points) and a point, then have the distance between them computed. Or find an intersection of two great arcs.

Of course, azimuth calculations are also included: find an azimuth from one point to another, or, less trivially, find a point at a given distance and azimuth (range and bearing) from a given one.

In particular, two functions are quite difficult to find in any piece of software:
  • Geodesic distance and azimuth (geodesic line is the shortest path between two points on the Earth ellipsoid).
  • Elliptic great arc distance, measured along a line drawn on an ellipsoid so that its projection on a sphere is a great circle arc.
The program stores a number of points on Earth and then allows you to refer to them by names. It will also accept data from an ASCII file (or write to one).

Various display and input formats are supported: deg/min/sec, decimal degrees, deg/min/fraction. (And yes, conversion from geographic to geocentric latitude, strangely omitted in quite a few programs of this kind, has not been forgotten about.)

This DOS version has been designed to behave well on the HP Palmtop machines (95, 100 or 200 LX). The program file size is just 64k what makes is especially suitable for use on that platform.


[Download] sph-lx.zip Spheric/LX for DOS and HP 95/100/200LX Palmtops (not the Windows CE models!) (1.42A, 2003/07/31)

In this version the Spheric/LX executable has been patched to make the Turbo Pascal code compatible with Windows XP on faster computers. The patch does not affect how the program runs on HPLX palmtops. The documentation also has been updated.

Click here to find Spheric for Windows


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Posted 1995/11/05; last updated 2003/07/31 Copyright © 1995-2003 by J. Andrzej Wrotniak