rdelta            160 core/gps.c     static t_rectangular rdelta;                           // distance to destination (metric N/E)
rdelta            288 core/gps.c         geo2rect                (&delta, &rdelta, ist.lat_w);                   // Distance in m (je N/E)
rdelta            289 core/gps.c         rect2polar              (&rdelta, &pdelta);                             // Distance in degrees m and grad