Star tracker
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An accuracy measurement method for star trackers based on direct astronomic observation Open
Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. T…
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CryoSat Ice Baseline-D validation and evolutions Open
The ESA Earth Explorer CryoSat-2 was launched on 8 April 2010 to monitor the precise changes in the thickness of terrestrial ice sheets and marine floating ice. To do that, CryoSat orbits the planet at an altitude of around 720 km with a r…
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Optical system design of star sensor and stray light analysis Open
Background: Star sensor is one of the precise attitude determination sensors. It is an electro-optical system that takes an image from a set of stars and by comparing it with the star catalogue determines angle deviation of the satellite a…
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Space Debris Detection and Positioning Technology Based on Multiple Star Trackers Open
This paper focuses on the opportunity to use multiple star trackers to help space situational awareness and space surveillance. Catalogs of space debris around Earth are usually based on ground-based measurements, which rely on data provid…
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Novel approach to improve the attitude update rate of a star tracker Open
The star tracker is widely used in attitude control systems of spacecraft for attitude measurement. The attitude update rate of a star tracker is important to guarantee the attitude control performance. In this paper, we propose a novel ap…
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A Hamming Distance and Spearman Correlation Based Star Identification Algorithm Open
This paper presents a novel star identification algorithm for a 'lost-in-space' mode star tracker. The Spearman-correlation approach provides reliable recognition even when the captured images are swayed and biased from the onboard star pa…
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A Comprehensive Calibration Method for a Star Tracker and Gyroscope Units Integrated System Open
The integration of a star tracker and gyroscope units (GUs) can take full advantage of the benefits of each, and provide continuous and accurate attitude information with a high update rate. The systematic error calibration of the integrat…
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Local Observability Analysis of Star Sensor Installation Errors in a SINS/CNS Integration System for Near-Earth Flight Vehicles Open
Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated navigation is a fully autonomous and high precision method, which has been widely used to improve the hitting accuracy and quick reaction capability of …
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Efficient Star Identification Using a Neural Network Open
The required precision for attitude determination in spacecraft is increasing, providing a need for more accurate attitude determination sensors. The star sensor or star tracker provides unmatched arc-second precision and with the rise of …
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An Extended Kalman Filter-Based Attitude Tracking Algorithm for Star Sensors Open
Efficiency and reliability are key issues when a star sensor operates in tracking mode. In the case of high attitude dynamics, the performance of existing attitude tracking algorithms degenerates rapidly. In this paper an extended Kalman f…
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Motion Blurred Star Image Restoration Based on MEMS Gyroscope Aid and Blur Kernel Correction Open
Under dynamic conditions, motion blur is introduced to star images obtained by a star sensor. Motion blur affects the accuracy of the star centroid extraction and the identification of stars, further reducing the performance of the star se…
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Autonomous Recalibration of Star Trackers Open
Star trackers must be calibrated prior to flight so that they can make accurate measurements of star positions within the instrument field of view. This calibration is usually performed in atmosphere and after the sensor is launched; it is…
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Star Identification and Attitude Determination With Projective Cameras Open
Images of starfields collected by a projective camera are useful for a variety of scientific and engineering purposes. This utility is exemplified by star trackers, which are amongst the most commonly used sensors for determining the attit…
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Modeling of intensified high dynamic star tracker Open
An intensified high dynamic star tracker (IHDST) is a photoelectric instrument and stably outputs three-axis attitude for a spacecraft at very high angular velocity. The IHDST uses an image intensifier to multiply the incident starlight. T…
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Autonomous star sensor ASTRO APS: flight experience on Alphasat Open
Jena-Optronik GmbH, located in Jena/Germany, has profound experience in designing and manufacturing star trackers since the early 80s. Today the company has a worldwide leading position in supplying geo-stationary and Earth observation sat…
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Introducing SOST: An Ultra-Low-Cost Star Tracker Concept Based on a Raspberry Pi and Open-Source Astronomy Software Open
Absolute attitude estimation sensors provide high accuracy pointing capabilities to spacecraft, but as developed thus far, they constitute a large fraction of CubeSat mission's budget. We introduce SPE Lab Open Star Tracker (SOST), an ultr…
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Centroid error compensation method for a star tracker under complex dynamic conditions Open
The traditional approach of a star tracker for reducing the dynamic error concentrates on a single frame of star images. Through correlating adjacent star images together with their angular relations sensed by a gyroscope unit (GU), the at…
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Robust and accurate star segmentation algorithm based on morphology Open
Star tracker is an important instrument of measuring a spacecraft's attitude; it measures a spacecraft's attitude by matching the stars captured by a camera and those stored in a star database, the directions of which are known. Attitude a…
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Attitude-correlated frames adding approach to improve signal-to-noise ratio of star image for star tracker Open
When applied inside Earth's atmosphere, the star tracker is sensitive to sky background produced by atmospheric scattering and stray light. The shot noise induced by the strong background reduces star detection capability and even makes it…
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Autonomous optical navigation using nanosatellite-class instruments: a Mars approach case study Open
This paper examines the effectiveness of small star trackers for orbital estimation. Autonomous optical navigation has been used for some time to provide local estimates of orbital parameters during close approach to celestial bodies. Thes…
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HIGH-PRECISION ATTITUDE ESTIMATION METHOD OF STAR SENSORS AND GYRO BASED ON COMPLEMENTARY FILTER AND UNSCENTED KALMAN FILTER Open
Determining the attitude of satellite at the time of imaging then establishing the mathematical relationship between image points and ground points is essential in high-resolution remote sensing image mapping. Star tracker is insensitive t…
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False Star Filtering for Star Sensor Based on Angular Distance Tracking Open
The reliability of star sensor in a harsh environment has recently become a research hotspot. In some harsh environment such as plume interference, a large number of false stars can be observed, leading to failure in star identification. I…
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An Evaluation of Low-Cost Vision Processors for Efficient Star Identification Open
Star trackers are navigation sensors that are used for attitude determination of a satellite relative to certain stars. A star tracker is required to be accurate and also consume as little power as possible in order to be used in small sat…
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A Compressed and High-Accuracy Star Tracker with On-Orbit Deployable Baffle for Remote Sensing CubeSats Open
CubeSats have been widely used in remote sensing applications such as global coverage, hotspots revisited, etc. However, due to the strict size limitation, the high-accuracy measuring instruments such as star tracker are too large to be ap…
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Star Tracker Geometric Calibration Through Full-State Estimation Including Attitude Open
A star tracker calibration method using star images is presented in this paper. Unlike previous works, the proposed method estimates all parameters and the attitudes at once in a single least-squares formulation for the optimal calibration…
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Orbit-Attitude Predictive Control in the Vicinity of Asteroids with In Situ Gravity Estimation Open
This paper presents an integrated model-learning predictive control scheme for spacecraft orbit-attitude station-keeping in the vicinity of asteroids. The orbiting probe relies on optical and laser navigation while attitude measurements ar…
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Universal Verification Platform and Star Simulator for Fast Star Tracker Design Open
Developing star trackers quickly is non-trivial. Achieving reproducible results and comparing different algorithms are also open problems. In this sense, this work proposes the use of synthetic star images (a simulated sky), allied with th…
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High-Accuracy Real-Time Attitude Determination and Imagery Positioning System for Satellite-Based Remote Sensing Open
The precise attitude determination and imagery positioning is crucial for remote sensing satellites to accomplish diverse observation missions. However, the complex fluctuations of environmental conditions result in severe and time-variant…
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Observation angular distance error modeling and matching threshold optimization for terrestrial star tracker Open
Observation angular distance error, as the difference between the actual observation angular distance and the reference angular distance, is an important parameter that affects the identification success rate, attitude measurement accuracy…
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Algorithm with Patterned Singular Value Approach for Highly Reliable Autonomous Star Identification Open
In the work reported in this paper, a lost-in-space star pattern identification algorithm for agile spacecraft was studied. Generally, the operation of a star tracker is known to exhibit serious degradation or even failure during fast atti…