The PoGOLite Star Tracker System
2009 (English)In: 2008 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (2008 NSS/MIC), 2009, 765-767 p.Conference paper (Refereed)
PoGOLite is a balloon-borne experiment which will study polarised soft gamma-ray emission from astrophysical targets in the 25keV - 80keV energy range by applying well-type phoswich detector technology . Polarised gamma-rays are expected from a wide variety of sources including rotation-powered pulsars, accreting black holes and neutron stars, and jet-dominated active galaxies. Polarization measurements provide a powerful probe of the gamma-ray emission mechanism and the distribution of magnetic and radiation fields around the source. The polarization is determined using Compton scattering and photoelectric absorption in an array of 217 plastic scintillators. The PoGOLite polarimeter has a field of view of 2.4 degrees x 2.4 degrees and must be kept aligned to objects of interest on the sky within 5% of the FOV to secure a minimum detectable polarization MDP=10% for a 200 mCrab source. This alignment can be obtained by mean of different attitude sensors: a DGPS (Differential Global Positioning System), two star trackers and gyroscopes. The most accurate sensor is the star tracker which is the focus of this paper. Preliminary studies  and calibration have been made which pave the way to an autonomous star tracking device which together with the other attitude control devices will reconstruct the pointing solution.
Place, publisher, year, edition, pages
2009. 765-767 p.
, IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, ISSN 1082-3654
Active - galaxies, Attitude sensors, Balloon-borne experiment, Black holes, Energy ranges, Field of views, Gamma-ray emission, Neutron stars, Phoswich detector, Photoelectric absorption, Plastic scintillator, Polarization measurements, Positioning system, Radiation field, Star tracker, Star tracking, Compton scattering, Flight dynamics, Galaxies, Polarization, Scintillation counters, Sensors, Stars
IdentifiersURN: urn:nbn:se:kth:diva-30733DOI: 10.1109/NSSMIC.2008.4774604ISI: 000268656000009ScopusID: 2-s2.0-67649222534ISBN: 978-1-4244-2714-7OAI: oai:DiVA.org:kth-30733DiVA: diva2:401987
IEEE Nuclear Science Symposium/Medical Imaging Conference, Dresden, GERMANY, OCT 19-25, 2008
QC 201103042011-03-042011-03-042011-03-04Bibliographically approved