Comparison of latitude and UT1-TAI observations derived from optical astrometry and the Doppler observation at Mizusawa
Abstract
The residuals of the latitude and UT1-TAI observations derived from optical astrometry by using various telescopes and the Doppler observation at Mizusawa are compared with the aid of the IRIS system's ERP. The residuals of the Danjon Astrolabe and the PZT are compared by using the ERP obtained from both the IRIS and the IPMS. The results show that the residuals due to differences in the ERP, IPMS - IRIS, were (4.1 + or - 0.2) marcsec in latitude and (-0.58 + or - 0.04) ms in UT1-TAI during October 1980 - December 1987. The residuals of the latitude and UT1-TAI at Mizusawa derived from the optical observations show changes since about 1984. Differences of the residuals of latitude observations at Mizusawa between the PZT and the Doppler shows variations and UT1-TAI since about 1984. This trend may be interpreted in terms of variations of local coordinates, catalog errors, or local geophysical variations.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- November 1990
- Bibcode:
- 1990A&AS...86...95K
- Keywords:
-
- Astrometry;
- Astronomical Photometry;
- Doppler-Fizeau Effect;
- Earth Rotation;
- Latitude Measurement;
- Periodic Variations;
- Telescopes;
- Astronomy