dorsal/arxiv
View SchemaObervational Model for Microarcsecond Astrometry with the Space Interferometry Mission
| Authors | Mark H. Milman, Slava G. Turyshev |
|---|---|
| Categories | |
| ArXiv ID | physics/0301047 |
| URL | https://arxiv.org/abs/physics/0301047 |
| DOI | 10.1117/1.1576405 |
| Journal | Opt.Eng. 42 (2003) 1873-1883 |
Abstract
The Space Interferometry Mission (SIM) is a space-based long-baseline optical interferometer for precision astrometry. One of the primary objectives of the SIM instrument is to accurately determine the directions to a grid of stars, together with their proper motions and parallaxes, improving a priori knowledge by nearly three orders of magnitude. The basic astrometric observable of the instrument is the pathlength delay, a measurement made by a combination of internal metrology measurements that determine the distance the starlight travels through the two arms of the interferometer and a measurement of the white light stellar fringe to find the point of equal pathlength. Because this operation requires a non--negligible integration time to accurately measure the stellar fringe position, the interferometer baseline vector is not stationary over this time period, as its absolute length and orientation are time--varying. This conflicts with the consistency condition necessary for extracting the astrometric parameters which requires a stationary baseline vector. This paper addresses how the time-varying baseline is ``regularized'' so that it may act as a single baseline vector for multiple stars, and thereby establishing the fundamental operation of the instrument.
{
"annotation_id": "7f8863e9-95cf-42c5-bcde-bc1b2f7d0e8b",
"date_created": "2026-03-02T18:00:43.261000Z",
"date_modified": "2026-03-02T18:00:43.261000Z",
"file_hash": "2b545aaf45f822be6332458f7d12a10e3eff124b16dd5e702b5e885f2a4ff400",
"private": false,
"record": {
"abstract": "The Space Interferometry Mission (SIM) is a space-based long-baseline optical\ninterferometer for precision astrometry. One of the primary objectives of the\nSIM instrument is to accurately determine the directions to a grid of stars,\ntogether with their proper motions and parallaxes, improving a priori knowledge\nby nearly three orders of magnitude. The basic astrometric observable of the\ninstrument is the pathlength delay, a measurement made by a combination of\ninternal metrology measurements that determine the distance the starlight\ntravels through the two arms of the interferometer and a measurement of the\nwhite light stellar fringe to find the point of equal pathlength. Because this\noperation requires a non--negligible integration time to accurately measure the\nstellar fringe position, the interferometer baseline vector is not stationary\nover this time period, as its absolute length and orientation are\ntime--varying. This conflicts with the consistency condition necessary for\nextracting the astrometric parameters which requires a stationary baseline\nvector. This paper addresses how the time-varying baseline is ``regularized\u0027\u0027\nso that it may act as a single baseline vector for multiple stars, and thereby\nestablishing the fundamental operation of the instrument.",
"arxiv_id": "physics/0301047",
"authors": [
"Mark H. Milman",
"Slava G. Turyshev"
],
"categories": [
"physics.space-ph",
"astro-ph"
],
"doi": "10.1117/1.1576405",
"journal_ref": "Opt.Eng. 42 (2003) 1873-1883",
"title": "Obervational Model for Microarcsecond Astrometry with the Space Interferometry Mission",
"url": "https://arxiv.org/abs/physics/0301047"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "35ec9a42-d65c-4e3c-93ef-6984333bf65d",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}