| pe_great_elliptic_distance | |
Finds the distance and forward and inverse azimuths between two points along a great elliptic
void pe_great_elliptic_distance (double a, double e2, double lam1, double phi1, double lam2, double phi2, double *distance, double *az12, double *az21);
| a | Semimajor axis of the spheroid |
| e2 | Eccentricity squared of the spheroid |
| lam1 | Longitude value of the first point |
| phi1 | Latitude value of the first point |
| lam2 | Longitude value of the second point |
| phi2 | Latitude value of the second point |
| distance | Distance |
| az12 | Azimuth from the first to the second point |
| az21 | Azimuth from the second to the first point |
The pe_great_elliptic_distance function takes a spheroid and two geographic points and calculates the distance and azimuths along the great elliptic. A great elliptic is the line formed by intersecting a plane with the surface of a spheroid. The plane is defined by the center of the spheroid and two points on its surface. Set e2 to zero to calculate distances on a sphere. The geographic coordinates and the azimuths are in radians. The azimuth value range is -π ≤ azimuth ≤ +π. An azimuth is measured positive clockwise with North equal to a zero azimuth. The semimajor axis (a) is usually given in meters, which means that the distance is in meters. To return the distance in another linear unit of measure, specify the semimajor axis in that unit of measure. As an example, if the semimajor axis is in US survey feet, the returned distance is in US survey feet.
Distance and forward and inverse azimuths (in radians)