GPS Manager User Manual -- Distances and bearings

|  |  | Distances and bearings

## Distances and bearings

There are two sets of formulas for computing distances and bearings that the user may choose

1. the so-called Law of Cosines for Spherical Trigonometry, that is not very accurate but is quite fast, and
2. the modified Rainsford's Method with Helmert's elliptical terms with a high degree of accuracy but slower; this method cannot be applied if one of the points is a geographical pole, in which case GPSMan applies the Law of Cosines.

In some situations, namely when computing the total distance along a track having very small distances between consecutive points, the Law of Cosines will yield results with large errors and therefore it should only be used on very slow computers.

Bearings in GPSMan are always geographic (True North).

|  |  | Distances and bearings