LSPE-STRIP: Requirements for the STR

Abstract

This document describes the requirements to optimize the Star Tracker (STR) design for LSPE-STRIP. A Star Tracker (STR) is a device used to determine the instantaneous pointing direction of the telescope, by looking at stars observed in the sky. Pointing direction is the direction at which the telescope optical centre is aimed. The STR is made of three components: 1. optics, aligned with the telescope optical centre (or off-setted of a known amount); 2). imager, able to collect an image of the stars observed on the sky; 3). processor, able to process the images, store them and communicate with the telescope control system. The work presented here is aimed at the optimization of optics and camera parameters. In particular, the relevant optics and camera parameters must be optimized looking at the number of stars observed per frame by the STR.