Hi, We are a group of Mechanical Engineering students from Imperial College, London, UK working on a Alt-Az telescope that is designed to automatically track satellites and are facing a few little difficulties that hopefully you guys can help us with. Our main problems are aligning the primary and secondary mirrors and the tracking system, specifically the encoders. The telescope is about 2m high with a 50cm diameter primary mirror and a secondary of about 15cm. The secondary mirror is on a inverted optical table mount and so its plane can be adjusted. There is a small tertiary mirror that is angled at 45 degrees that reflects the light into a camera attached directly to a monitor. The control system is based around a 386 computer, a program has been written that uses TLE files and then controls two friction drives to find and then track satellites. Feedback is by means of two optical encoders (one per axis). The big thing that we need to sort out is aligning the primary and secondary mirrors and any help on this would be appreciated (due to constraints beyond our control we can not drill holes and preferably not mark the main mirror). The encoders each consist of two optical discs (one containing the most significant bits) the current problem is that the input into the computer reads 1,2,3,4,5,98,99,100,137 etc. We believe this may be caused by misalignment of the discs but are unsure how to overcome this problem (aligning two discs to a hundredth of a degree doesn't sound too easy) and we do not have a sufficient budget to buy encoders. If any one out there has any good ideas we would love to hear from you, or any good websites, textbooks etc. We are very new to all this stuff so any help no matter how obvious it seems would be great. Regards Jon and group ----------------------------------------------------------------- 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 : Thu May 17 2001 - 07:36:46 PDT