EXPLORATION OF SOURCE FREQUENCY PHASE REFERENCING TECHNIQUES FOR ASTROMETRY AND OBSERVATIONS OF WEAK SOURCES WITH HIGH FREQUENCY SPACE VERY LONG BASELINE INTERFEROMETRY
- ICRAR, UWA, Perth (Australia)
- Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Chuou, Sagamihara, Kanagawa 252-5210 (Japan)
Space very long baseline interferometry (S-VLBI) observations at high frequencies hold the prospect of achieving the highest angular resolutions and astrometric accuracies, resulting from the long baselines between ground and satellite telescopes. Nevertheless, space-specific issues, such as limited accuracy in the satellite orbit reconstruction and constraints on the satellite antenna pointing operations, limit the application of conventional phase referencing. We investigate the feasibility of an alternative technique, source frequency phase referencing (SFPR), to the S-VLBI domain. With these investigations we aim to contribute to the design of the next generation of S-VLBI missions. We have used both analytical and simulation studies to characterize the performance of SFPR in S-VLBI observations, applied to astrometry and increased coherence time, and compared these to results obtained using conventional phase referencing. The observing configurations use the specifications of the ASTRO-G mission for their starting point. Our results show that the SFPR technique enables astrometry at 43 GHz, using alternating observations with 22 GHz, regardless of the orbit errors, for most weathers and under a wide variety of conditions. The same applies to the increased coherence time for the detection of weak sources. Our studies show that the capability to carry out simultaneous dual frequency observations enables application to higher frequencies, and a general improvement of the performance in all cases, hence we recommend its consideration for S-VLBI programs.
- OSTI ID:
- 21582795
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 142, Issue 5; Other Information: DOI: 10.1088/0004-6256/142/5/157; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
HIGH-PRECISION ASTROMETRIC MILLIMETER VERY LONG BASELINE INTERFEROMETRY USING A NEW METHOD FOR ATMOSPHERIC CALIBRATION
VLBI ASTROMETRY OF PSR J2222-0137: A PULSAR DISTANCE MEASURED TO 0.4% ACCURACY