Radiotelescope low-rate tracking using dither.

Details Radiotelescope low-rate tracking using dither. Radiotelescope low-rate tracking using dither.

Apr 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998jgcd...21..349g&link_type=abstract

J. Guid. Control Dyn., Vol. 21, No. 2, p. 349 - 351

Computer Science

Performance

Radio Telescopes: Pointing Accuracy

Scientific paper

Many radiotelescopes cannot precisely point at a certain part (about 5%) of the sky that requires tracking with very low azimuth angular rates, because of dry rolling friction. The authors analyze the NRAO's Green Bank Telescope located in West Virginia. It has a unique configuration characterized by the offset reflector. Its size, weight, and especially configuration create difficulties in precision tracking. For rates lower than 0.3 mdeg/s a nonsmooth motion with breakaways may occur. The peak-to-peak pointing error due to friction is 1.4 mdeg. A high-frequency external signal injected into a system is called a dither. Injection of such signals into a nonlinear system eliminates limit cycles. The authors show that dither improves the telescope pointing at low tracking rates. They will show that the high-frequency dither signal excites local vibrations only (at the wheels) causing the breaking of the friction-stiction phenomena. The vibrations are not transmitted through the telescope structure, thus not impacting its pointing performance.

Affiliated with

Also associated with

No associations

Rating

Radiotelescope low-rate tracking using dither. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Radiotelescope low-rate tracking using dither., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiotelescope low-rate tracking using dither. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1604870