>Here is a part of a review of the Vixen... it doesn't appear to do a very >good job. I can offer some comments based on personal experience with the VIXEN SkySensor 2000 PC: > When I tested this with several passes of the International Space >Station and Mir, SkySensor never placed the satellite in the main telescope >eyepiece. Close, within the finder, but not in the main optics. There are several possible reasons for this: 1. Inaccurate TLEs; those of ISS are ageing rather quickly. 2. The internal clock must be set to 1 second or better if possible. 3. The coordinates of the observer may be inaccurate or in the wrong geodetic system (i.e. not in WGS84). >One catch: if the mount slews up from the west, when it reaches the meridian >it stops and waits for you to command it to flip itself to the other half of >the sky, where it will resume tracking the satellite to the east. This is indeed a very annoying feature. I have eliminated it by operating the SkySensor in altazimuth mode. This avoids the reversal when the meridian is crossed. >Also, it was under high-speed tracking that I did notice some image jitter, >making it that much harder to make out the shape of an orbiting object such >as Mir. To see a shape is fairly hopeless anyway unless one uses very high magnification uner perfect seeing conditions. I have noticed the jitter as well. It can be much reduced by carefully balancing the telescope mount. However, with only one counterweight not all the torques can be compensated. In summary, I have seen many objects (satellites and rockets) with the Skysensor which I would never have found without it. It probably isn't perfect (which instrument is ?), but it does a decent job for its price. Bruno Tilgner ----------------------------------------------------------------- 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 Aug 08 2000 - 14:15:57 PDT