Generation and Validation of On-Board Star Catalog for RESOURCESAT-I Star Tracker

2004 ◽  
Author(s):  
Vandana Singh ◽  
D. Pullaiah ◽  
J. Sreenivasa Rao ◽  
T. Shashikala ◽  
G. Nagendra Rao ◽  
...  
Keyword(s):  
Star Tracker ◽  
Star Catalog

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.

Star tracker for remote sensing satellites

1994 ◽  
Author(s):  
Philip C. Thomas ◽  
Gangan Prathap ◽  
V. Koteswara Rao ◽  
Yashwant K. Jain
Keyword(s):  
Remote Sensing ◽  
Star Tracker

Stray-light reduction in a WFOV star tracker lens

1991 ◽  
Author(s):  
Isabella T. Lewis ◽  
Arno G. Ledebuhr ◽  
Timothy S. Axelrod ◽  
Scott A. Ruddell
Keyword(s):  
Stray Light ◽  
Star Tracker ◽  
Light Reduction

Wide-field-of-view star tracker camera

1991 ◽  
Author(s):  
Isabella T. Lewis ◽  
Arno G. Ledebuhr ◽  
Timothy S. Axelrod ◽  
Joseph F. Kordas ◽  
Robert Hills
Keyword(s):  
Field Of View ◽  
Star Tracker ◽  
Wide Field ◽  
Wide Field Of View

Algorithm Design and Implementation of Dynamic Star Simulator

2013 ◽  
Vol 722 ◽  
pp. 187-193
Author(s):  
Xiao Fang Zhao ◽  
Guang Bin Liu ◽  
Chao Shan Liu
Keyword(s):  
Traditional Method ◽  
Algorithm Design ◽  
Star Tracker ◽  
Simulation Algorithm ◽  
Arc Length ◽  
Visual Axis ◽  
Star Image ◽  
Design And Implementation ◽  
Simulation Testing ◽  
Celestial Sphere

In order to realize the simulation testing and calibration of star tracker in the lab, a simulation algorithm for dynamic and celestial sphere star image was proposed. This algorithm could complete simulation of star image at any time and any visual axis point, also could realize in-orbit simulation according to a given track. A new method of space district dividing was also presented in order to improve the traditional method of space district dividing by ascension and declination, fully considered declination arc length gradually shortened with latitude increasing. It can remarkably enhance the updating frequency simulation star image.

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