Fast star identification of super large infrared star catalog

2021 ◽  
Author(s):  
Chunxiao Zhang ◽  
Shixiang Cao ◽  
Hongyan He
Keyword(s):  
Star Catalog ◽  
Star Identification ◽  
Infrared Star

scholarly journals Lost-in-Space Star Identification Using Planar Triangle Principal Component Analysis Algorithm

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Fuqiang Zhou ◽  
Tao Ye
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Identification Algorithm ◽  
Star Sensor ◽  
Star Catalog ◽  
Star Identification ◽  
Triangle Method ◽  
Space Star ◽  
Guide Star

It is a challenging task for a star sensor to implement star identification and determine the attitude of a spacecraft in the lost-in-space mode. Several algorithms based on triangle method are proposed for star identification in this mode. However, these methods hold great time consumption and large guide star catalog memory size. The star identification performance of these methods requires improvements. To address these problems, a star identification algorithm using planar triangle principal component analysis is presented here. A star pattern is generated based on the planar triangle created by stars within the field of view of a star sensor and the projection of the triangle. Since a projection can determine an index for a unique triangle in the catalog, the adoption of thek-vector range search technique makes this algorithm very fast. In addition, a sharing star validation method is constructed to verify the identification results. Simulation results show that the proposed algorithm is more robust than the planar triangle andP-vector algorithms under the same conditions.

scholarly journals Guide Star Selection for the Three-FOV Daytime Star Sensor

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1457 ◽  
Author(s):  
Liang Wu ◽  
Qian Xu ◽  
Haojing Wang ◽  
Hongwu Lyu ◽  
Kaipeng Li
Keyword(s):  
Short Wave ◽  
Optimal Number ◽  
Reference Points ◽  
Filter Method ◽  
Star Sensor ◽  
Star Catalog ◽  
Swir Band ◽  
Star Identification ◽  
Guide Star ◽  
Star Catalogs

To realize the application of the star sensor in the all-day carrier platform, a three-field-of-view (three-FOV) star sensor in short-wave infrared (SWIR) band is considered. This new prototype employs new techniques that can improve the detection capability of the star sensor, when the huge size of star identification feature database becomes a big obstacle. Hence, a way to thin the guide star catalog for three-FOV daytime star sensor is studied. Firstly, an introduction of three-FOV star sensor and an example of three-FOV daytime star sensor with narrow FOV are presented. According to this model and the requirement of triangular star identification method, two constraints based on the number and the brightness of the stars in FOV are put forward for guide star selection. Then on the basis of these constraints, the improved spherical spiral method (ISSM) is proposed and the optimal number of reference points of ISSM is discussed. Finally, to demonstrate the performance of the ISSM, guide star catalogs are generated by ISSM, magnitude filter method (MFM), 1st order self-organizing guide star selection method (1st-SOPM) and the spherical spiral method (SSM), respectively. The results show that the guide star catalog generated by ISSM has the smallest size and the number and brightness characteristics of its guide stars are better than the other methods. ISSM is effective for the guide star selection in the three-FOV daytime star sensor.

scholarly journals Fast Access for Star Catalog Based on Locality-Sensitive Hashing

2018 ◽  
Vol 36 (5) ◽  
pp. 988-994
Author(s):  
Hailong Zhu ◽  
Bin Liang ◽  
Tao Zhang
Keyword(s):  
Central Star ◽  
Locality Sensitive Hashing ◽  
Practical Application ◽  
Error Limit ◽  
Star Catalog ◽  
Distance Error ◽  
Star Identification ◽  
Point Set ◽  
Fast Access ◽  
Better Than

In order to improve the access speed and robustness of star catalog database during star identification, an algorithm based on locality-sensitive hashing is proposed. First, according to principle of star identification, the angle distances are quantified on the basis of angle distance error limit, and the order star set pattern is transformed into an array of integers, which has locally sensitive hash characteristics. Then key of hash obtain by hashing the array of integers with Stlport, and the value of hashing is a set of central star number in the ordered star point set pattern. Numerical simulation results indicate that the time complexity of proposed algorithm is O(1), which is much better than direct search, binary search and k-vector search technology. In addition, the proposed algorithm is robustness due to the affect is not significant as the performance influenced by angle distance error limit. Considering practical application, the error limit of angle distance could be chose as 1 pixel, the number of quantified angle distances could be chosen as 3. Under this condition, the collision rate in hashing table is 0.74%, the average searching time is 1.007 4 and the average consuming time is 22 μs during star identification.

scholarly journals CPC2 Reduction with Hipparcos and Proper Motions in The Southern Hemisphere

1998 ◽  
Vol 11 (1) ◽  
pp. 551-551
Author(s):  
N. Zacharias ◽  
M.I. Zacharias ◽  
C. de Vegt ◽  
C.A. Murray
Keyword(s):  
Southern Hemisphere ◽  
Systematic Errors ◽  
Reference Star ◽  
Proper Motions ◽  
Positional Accuracy ◽  
Star Catalog ◽  
Naval Observatory ◽  
Celestial Reference System ◽  
First Time ◽  
Better Than

The Second Cape Photographic Catalog (CPC2) contains 276,131 stars covering the entire Southern Hemisphere in a 4-fold overlap pattern. Its mean epoch is 1968, which makes it a key catalog for proper motions. A new reduction of the 5687 plates using on average 40 Hipparcos stars per plate has resulted in a vastly improved catalog with a positional accuracy of about 40 mas (median value) per coordinate, which comes very close to the measuring precision. In particular, for the first time systematic errors depending on magnitude and color can be solved unambiguously and have been removed from the catalog. In combination with the Tycho Catalogue (mean epoch 1991.25) and the upcoming U.S. Naval Observatory CCD Astrograph Catalog (UCAC) project proper motions better than 2 mas/yr can be obtained. This will lead to a vastly improved reference star catalog in the Southern Hemisphere for the final Astrographic Catalogue (AC) reductions, which will then provide propermotions for millions of stars when combined with new epoch data. These data then will allow an uncompromised reduction of the southern Schmidt surveys on the International Celestial Reference System (ICRS).

A Research on Navigation Star Catalog Selection Algorithm Based on SVM

2013 ◽  
Vol 706-708 ◽  
pp. 613-617
Author(s):  
Fu Cheng Liu ◽  
Zhao Hui Liu ◽  
Wen Liu ◽  
Dong Sheng Liang ◽  
Kai Cui ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Field Of View ◽  
Support Vector ◽  
Selection Algorithm ◽  
Boltzmann Entropy ◽  
Local Criterion ◽  
Star Catalog ◽  
Uniform Sampling ◽  
Global Criterion ◽  
Small Capacity

A navigation star catalog (NSC) selection algorithm via support vector machine (SVM) is proposed in this paper. The sphere spiral method is utilized to generate the sampling boresight directions by virtue of obtaining the uniform sampling data. Then the theory of regression analysis methods is adopted to extract the NSC, and an evenly distributed and small capacity NSC is obtained. Two criterions, namely a global criterion and a local criterion, are defined as the uniformity criteria to test the performance of the NSC generated. Simulations show that, compared with MFM, magnitude weighted method (MWM) and self-organizing algorithm(S-OA), the Boltzmann entropy (B.e) of SVM selection algorithm (SVM-SA) is the minimum, to 0.00207. Simultaneously, under the conditions such as the same field of view (FOV) and elimination of the hole, both the number of guide stars (NGS) and standard deviation (std) of SVM-SA is the least, respectively 7668 and 2.17. Consequently, the SVM-SA is optimal in terms of the NGS and the uniform distribution, and has also a strong adaptability.

Study on Dynamic IR Image Generation of Space Target

2014 ◽  
Vol 1044-1045 ◽  
pp. 1343-1348
Author(s):  
Wu Can He ◽  
Shou Yi Liao ◽  
Zuo Yu Zhang ◽  
He Xin Zhang
Keyword(s):  
Infrared Imaging ◽  
Three Dimensional ◽  
Orbit Space ◽  
Guidance System ◽  
Image Generation ◽  
Hardware In The Loop ◽  
Imaging Guidance ◽  
Infrared Star ◽  
Objective Basis ◽  
Space Target

Dynamic IR image generation of space target is one of the key technologies in hardware in the loop simulation for the infrared imaging guidance system. The three-dimensional entity model is created in the Creator, Sinda/Fluint is used to analyze each part of dynamic infrared radiation characteristics from on-orbit Space Target, on the basis of the LRS infrared star catalogues, celestial background modeling is built. In Vega, the dynamic IR image of space target is generated. The simulation results show that the dynamic IR image of Space Target provide the important objective basis for the hardware in the loop simulation for the infrared imaging guidance system.

STAR IDENTIFICATION ALGORITHM FOR UNCALIBRATED, WIDE FOV CAMERAS

2015 ◽  
Vol 149 (6) ◽  
pp. 182 ◽  
Author(s):  
Mohamad Javad Ajdadi ◽  
Mahdi Ghafarzadeh ◽  
Mojtaba Taheri ◽  
Ehsan Mosadeq ◽  
Mahdi Khakian Ghomi
Keyword(s):  
Identification Algorithm ◽  
Star Identification ◽  
Wide Fov
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