The mathematics for equatorial mount pointing are this simple that not even a piece of paper is needed: To provide a minimal rotation about the declination axis the RA axis (normally pointing towards the Polar Star) has to stand perpendicular to the approximated plane described by the point of the satellite rising, the maximum elevation point, the point the satellite touches the horizon again and the observer in the center. Then mainly this RA axis has to be used to track the satellite, with little movement of the Declination axis. In practical speaking, the RA axis has to point into the opposite azimuth where the maximum elevation occurs, and it has to be elevated against the horizon to 90° minus the maximum elevation of the satellite pass. An example: A satellite has its maximum elevation at 72° and the corresponding azimuth is 227° (SW). Then the RA axis has to point towards an azimuth of 47° (NE) and an elevation of (90° - 72°) = 18°. A drive rate can't be given as the satellite's apparent velocity changes over the pass. This method is practiced by myself using a 70mm refractor telescope without any electronics (ISS and STS give some illusion of a not pointlike appearance). Moritz Heger Germany 48.7080°N 11.3994°E 370m WGS84 ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Tue Apr 03 2001 - 13:44:57 PDT