Session
Technical Session VIII: Frank J. Redd Student Competition
Abstract
Small satellite-enabled terrestrial target tracking applications from low-Earth orbit are demanding stringent pointing performance, prompting the need for developing high-precision attitude estimation and control systems that adhere to cost and mass constraints. The attitude determination and control system onboard the Space Flight Laboratory’s NEMO-class satellite platforms uses an extended Kalman filter and low-cadence (1Hz) star-tracker measurements to constrain the attitude and rate estimation errors to within 0.05° and 0.04°/s (2-σ), respectively. In addition, the pointing error of this satellite platform is constrained to below 0.3° (2-σ) for ground target tracking applications. However, in order to meet the stability requirements of future missions that require precise target-tracking capabilities, a combination of star tracker and high frequency gyro-measurements is preferred. Leveraging high-grade miniaturized and commercially-accessible fiber optic gyroscopes (FOGs) with sampling frequencies of ≥ 2Hz, a high-performance attitude determination and control system suitable for target tracking micro- and nano-satellites is under development at the Space Flight Laboratory of Toronto, Canada. This paper discusses the design of an attitude estimation filter tailored to constrain the ground target pointing error of NEMO-class satellites to well below 0.3° (3-σ). To evaluate the performance of this filter, precision target tracking simulations were conducted, and the results demonstrated significant improvement in some state estimates when a combination of three-orthogonally mounted FOGs operating at high cadence (5Hz) and a single star tracker operating at 1Hz were implemented.
Fiber Optic Gyro-Based Attitude Determination for High-Performance Target Tracking
Small satellite-enabled terrestrial target tracking applications from low-Earth orbit are demanding stringent pointing performance, prompting the need for developing high-precision attitude estimation and control systems that adhere to cost and mass constraints. The attitude determination and control system onboard the Space Flight Laboratory’s NEMO-class satellite platforms uses an extended Kalman filter and low-cadence (1Hz) star-tracker measurements to constrain the attitude and rate estimation errors to within 0.05° and 0.04°/s (2-σ), respectively. In addition, the pointing error of this satellite platform is constrained to below 0.3° (2-σ) for ground target tracking applications. However, in order to meet the stability requirements of future missions that require precise target-tracking capabilities, a combination of star tracker and high frequency gyro-measurements is preferred. Leveraging high-grade miniaturized and commercially-accessible fiber optic gyroscopes (FOGs) with sampling frequencies of ≥ 2Hz, a high-performance attitude determination and control system suitable for target tracking micro- and nano-satellites is under development at the Space Flight Laboratory of Toronto, Canada. This paper discusses the design of an attitude estimation filter tailored to constrain the ground target pointing error of NEMO-class satellites to well below 0.3° (3-σ). To evaluate the performance of this filter, precision target tracking simulations were conducted, and the results demonstrated significant improvement in some state estimates when a combination of three-orthogonally mounted FOGs operating at high cadence (5Hz) and a single star tracker operating at 1Hz were implemented.
