| タイトル | Fast Switching and Precision Relative Astrometry at the DSN |
| 著者（英） | Bagri, Durgadas; Majid, Walid |
| 著者所属（英） | Jet Propulsion Lab., California Inst. of Tech. |
| 発行日 | 2008-01-28 |
| 言語 | eng |
| 内容記述 | A) We are developing new techniques to improve astrometric accuracy: 1) Reducing switching time (approx. 60s) and angular separation (approx.1deg) between quasars; 2) Use of phase delay & bandpass calibration; 3) Techniques also applicable with future DSN Array. B) Initial set of observations carried out at the DSN show great promise. C) Continue DSN observations using fainter calibrators to study robustness and to verify and validate error estimates. (Eventually demo technique with spacecraft measurements). D) Viability of technique depends on existence of sufficient number of calibrators. (Determining what fraction of radio sources are compact at the VLBA) E) May be able to use calibrators with flux density approx. 50 mJy with calibrator <distance> 1deg. G) Relative precision of approx.0.5 nrad may be achievable. E) Absolute measurement always depends on knowledge of calibrator position. (Catalog maintained and improved). |
| NASA分類 | Astronomy |
| 権利 | Copyright |
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