AMICA, an astro-mapper for AMS     

Alessandro Monfardini  Paolo Trampus  Roberto Battiston  Corrado Gargiulo 《Astroparticle Physics》2006,25(6):355-360

The alpha magnetic spectrograph (AMS) is a composite particle detector to be accommodated on the International Space Station (ISS). AMS is mainly devoted to galactic, charged cosmic rays studies, antimatter and dark matter searches. Besides the main, classical physics goals, capabilities in the field of GeV and multi-GeV gamma astrophysics have been established and are under investigation by a number of groups. Due to the unsteadiness of the ISS platform, a star-mapper device is required in order to fully exploit the intrinsic arc-min angular resolution provided by the silicon tracker. A star-mapper is conceptually an imaging, optical instrument able to autonomously recognize a stellar field and to calculate its own orientation with respect to an inertial reference frame. AMICA (Astro Mapper for Instruments Check of Attitude) on AMS is responsible for providing real-time information that is going to be used off-line for compensating the large uncertainties in the ISS flight attitude and the structural degrees of freedom. In this paper, we describe in detail the AMICA sub-system, the accommodation/integration issues and the in-flight alignment procedure adopting identified galactic (Pulsars) and extra-galactic (AGNs) sources.  相似文献   

Exploring the possibilities for star-tracker assisted calibration of the six individual GOCE accelerometers   总被引：1，自引：0，他引：1  

P. N. A. M. Visser 《Journal of Geodesy》2008,82(10):591-600

A method has been developed and tested for estimating calibration parameters for the six accelerometers on board the Gravity field and steady-state Ocean Circulation Explorer (GOCE) from star tracker observations. These six accelerometers are part of the gradiometer, which is the prime instrument on board GOCE. It will be shown that by taking appropriate combinations of observations collected by the accelerometers, by modeling acceleration terms caused by gravity gradients from an a priori low-degree spherical harmonic expansion, and by modeling rotational acceleration terms derived from star-tracker observations, scale factors of each of the accelerometers can be estimated for each axis. Simulated observations from a so-called end-to-end simulator were used to test the method. This end-to-end simulator includes a detailed model of the GOCE satellite, its instruments and instrument errors, and its environment. Results of the tests indicate that scale factors of all six accelerometers can be determined with an accuracy of around 0.01 for all components on a daily basis.  相似文献