Using HIPPARCOS Transit Data for Aperture Synthesis Imaging

Details Using HIPPARCOS Transit Data for Aperture Synthesis Imaging Using HIPPARCOS Transit Data for Aperture Synthesis Imaging

Aug 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997esasp.402..257q&link_type=abstract

Proceedings of the ESA Symposium `Hipparcos - Venice '97', 13-16 May, Venice, Italy, ESA SP-402 (July 1997), p. 257-262

Statistics

Applications

3

Scientific paper

The ESA Hipparcos astrometry satellite did not contain an imaging detector (such as a CCD) but used a modulating grid of alternating transparent and opaque bands to modulate the light from a given object. The Fourier coefficients of the modulated detector signal were the basis for the astrometric and photometric processing leading to the Hipparcos Catalogue. These coefficients are included (for a subset of the stars) in the CD-ROM version of the Hipparcos Catalogue as the `Hipparcos Transit Data'. The modulation components are equivalent to the interference fringes from an interferometer with baselines of 0, ~=10 and ~=20 cm (at 550 nm wavelength) oriented along the scan direction of the satellite. Each scan, therefore, gives a few points on the complex uv plane, which is the Fourier transform of the image. All points collected through the mission lifetime fall onto two concentric circles corresponding to the two modulated components and a central point corresponding to the total flux of the scan. In a similar fashion to radio astronomy, it is possible to use these complex visibilities (including both amplitude and phase information) calculated from the Transit Data to create an aperture synthesis image of an object. Applications of the method are shown using a standard radio astronomy software package (Difmap, CLEAN) to deconvolve several images including: a new double star discovered by Hipparcos, a set of images showing annual parallax, and orbital motion in a binary.

Affiliated with

Also associated with

No associations

Rating

Using HIPPARCOS Transit Data for Aperture Synthesis Imaging 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 Using HIPPARCOS Transit Data for Aperture Synthesis Imaging, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Using HIPPARCOS Transit Data for Aperture Synthesis Imaging will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1879087