Paper 13094-15
Paper 13094-15
Advanced metrology sensor applications for improved pointing performance of the Greenland Telescope
16 June 2024 • 16:40 - 17:00 Japan Standard Time | Room G403/404, North - 4F
Abstract
The Greenland Telescope (GLT) currently achieves a blind pointing
accuracy of 2 arcseconds rms, sufficient for 230 GHz VLBI operations
at Pituffik Space Base. Plans to relocate the antenna to Summit
Station are underway to enable observations at >=690 GHz, which
requires improving pointing accuracy due to smaller beam sizes at
higher frequencies. Since achieving the ALMA-standard referenced
pointing accuracy of less than 1 arcsecond for single-dish operations
is impractical due to limited sensitivity, GLT's strategy involves
real-time adjustments using data from metrology sensors, following
the Systematic Pointing Error Model (SPEM) by the antenna manufacturer
(Vertex Antennas). This paper highlights our metrology system's
role in predicting pointing corrections through real-time monitoring
of inclinometers, linear, and temperature sensors. Additionally,
we introduce a night-viable optical guidescope system for astrometric
referencing of star-fields, aiming to enhance pointing precision
for high-frequency VLBI with the GLT.
Presenter
Ctr. for Astrophysics | Harvard & Smithsonian (United States)
Dr. Nimesh Patel is an astrophysicist and systems engineer working
at the Center for Astrophysics since 1994. He is working on the
Submillimeter Array since 1996, the Greenland Telescope since 2012,
and the Next Generation Event Horizon Telescope since 2020. He is
a member of the Event Horizon Telescope collaboration. Dr. Patel
obtained his PhD from the Indian Institute of Science, in 1990. He
was a postdoctoral research fellow at the Five College Radio Astronomy
Observatory, University of Massachusetts, from 1991 to 1994, before
joining the Harvard-Smithsonian Center for Astrophysics. His
research interests include molecular astrophysics, evolved stars,
interstellar medium, star-formation and astrophysical masers, radio
interferometry, high-speed analog to digital conversion, antenna
pointing and metrology. Dr. Patel is also very involved on various
projects related to education and outreach.