Requirements for CubeSat on-board sensors for identification of design and inertial characteristics

Abstract

In this paper, we discuss requirements formulation for CubeSat on-board sensors characteristics for solving identification problem. The problem is to estimate design and inertial parameters of CubeSat-format nanosatellite using on-board sensor measurements. Identification problem for CubeSats becomes more and more actual every year because CubeSat design becomes more complicated due to complex missions requirements. Modern CubeSats can be equipped with deployable solar panels, propulsion units and different types of transformable structures. This fact makes it necessary to study CubeSats as bodies with variable inertial and design characteristics. In this article the design parameter is fuel level in the CubeSat propulsion system and inertial parameters are inertial coefficients (inertia moments analog). We study requirements formulation for magnetometer and angular rate sensor, as this combination of sensors is the most popular in CubeSat development. The main idea of this paper is to study the sensitivity of measurements to estimated parameters. This sensitivity depends on time and measurement noise, large sensitivity leads to low estimation error. We conducted a numerical study and provide an algorithm which allows to define sensitivity-time-noise dependence for each type of sensors and formulate the requirements for their characteristics.