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.

Guide star catalog generation for short-wave infrared (SWIR) All-Time star sensor

2018 ◽  
Vol 89 (7) ◽  
pp. 075003 ◽  
Author(s):  
Wenjie Wang ◽  
Xinguo Wei ◽  
Jian Li ◽  
Guangjun Zhang
Keyword(s):  
Short Wave ◽  
Star Sensor ◽  
Star Catalog ◽  
Short Wave Infrared ◽  
Guide 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.

Optimization of guide star catalog for daytime star sensors

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040065
Author(s):  
Feng Wu ◽  
Xifang Zhu ◽  
Qingquan Xu ◽  
Ruxi Xiang ◽  
Qiuyang Yu ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Simple Calculation ◽  
High Signal ◽  
Star Sensor ◽  
Infrared Band ◽  
Star Catalog ◽  
Celestial Sphere ◽  
Guide Star ◽  
Star Pattern Identification ◽  
Navigation Information

Daytime star sensor provides accuracy navigation information to air vehicles near the ground in the daytime by observing stars. It has been an important development of modern star sensors. In order to achieve a high signal-to-noise ratio, daytime star sensors work in the infrared band to avoid interferences from sky background. Daytime star sensors output accurate attitudes by identifying the observed stars in the field of view (FOV) according to the loaded guide star catalog. Guide stars are usually required to be distributed uniformly on the celestial sphere to improve the performance of star pattern identification. The parameters including limiting magnitude and FOV are determined by processing the 2MASS star catalog as the original star data and performing star distribution statistics. After constellation features are discussed, the idea of distributing stars in the local FOV to constellations is put forward by using the star pair angular separations. An optimization algorithm to build the guide star catalog for daytime stars is proposed to achieve evenly distributed guide stars. The guide star catalog is established and analyzed, proving that the proposed algorithm has simple calculation and easy realization. The Boltzmann entropy of obtained guide star catalog drops two orders of magnitude. Guide stars are distributed more uniformly.

scholarly journals U.S. Naval Observatory Double Star CD 2006.5

2006 ◽  
Vol 2 (S240) ◽  
pp. 575-580 ◽  
Author(s):  
Brian D. Mason ◽  
William I. Hartkopf
Keyword(s):  
Binary Stars ◽  
Double Star ◽  
List Type ◽  
Star Catalog ◽  
Naval Observatory ◽  
Scale Calibration ◽  
Linear Elements ◽  
Visual Binary Stars ◽  
Star Catalogs ◽  
Magnitude Difference

AbstractThe U.S. Naval Observatory has produced its second CDROM of double star catalogs. This successor to the 2001.0 CDROM includes the latest versions (June 30 2006) of four major double star catalogs maintained at the USNO: •Washington Double Star Catalog (WDS),•Second Photometric Magnitude Difference Catalog,•Fourth Catalog of Interferometric Measurements of Binary Stars, and•Sixth Catalog of Orbits of Visual Binary Stars.Each of these catalogs had seen significant changes during the past six years; for example, the WDS has grown by over 150,000 measures and the number of systems in the Interferometric Catalog has nearly doubled. Other improvements include precise coordinates for the vast majority of systems, as well as new observing lists for tens of thousands of “neglected” doubles.Also included on this CDROM is a Catalog of Linear Elements for several hundred optical pairs. These elements should prove useful for improving the components' proper motions, as well as providing scale calibration out to several tens of arcseconds.As was done with its predecessor, the new CDROM is automatically distributed free of charge to members of the double star community and to astronomy libraries. Others may receive a complementary copy upon request.

The Guide Star Catalog, Version 1.2: An Astrometric Recalibration and Other Refinements

2001 ◽  
Vol 121 (3) ◽  
pp. 1752-1763 ◽  
Author(s):  
J. E. Morrison ◽  
S. Röser ◽  
B. McLean ◽  
B. Bucciarelli ◽  
B. Lasker
Keyword(s):  
Star Catalog ◽  
Guide Star

The Guide Star Catalog. II. Astrometric and Photometric Algorithms and Precision

1988 ◽  
pp. 235-237 ◽  
Author(s):  
Jane L. Russell ◽  
Barry M. Lasker ◽  
Helmut Jenkner
Keyword(s):  
Star Catalog ◽  
Guide Star

The Guide Star Catalog. I. Overview, History, and Prospective

1988 ◽  
pp. 229-233 ◽  
Author(s):  
Barry M. Lasker ◽  
Helmut Jenkner ◽  
Jane L. Russell
Keyword(s):  
Star Catalog ◽  
Guide Star

scholarly journals Precision vs. Accuracy in Star Catalogs

1995 ◽  
Vol 166 ◽  
pp. 372-372
Author(s):  
L. G. Taff ◽  
J. E. Morrison ◽  
R. L. Smart
Keyword(s):  
Random Error ◽  
A Priori ◽  
Systematic Errors ◽  
A Posteriori ◽  
New Techniques ◽  
Star Catalog ◽  
True Value ◽  
Reduction Methods ◽  
Star Catalogs ◽  
Comparable Amplitude

As better precision is achieved and more sophisticated reduction methods are created previously invisible biases surface. This has been especially true in astrometric Schmidt plate work. The problem of their amelioration is not fully solved and precision per se is meaningless in the presence of poor accuracy of comparable amplitude. Continuing to benignly neglect this issue puts us in the position of standing on only one statistical leg. New techniques have been designed to further minimize systematic errors. Of especial interest to star catalog analysis is the method of infinitely overlapping circles (Taff, Bucciarelli & Lattanzi, ApJ 361, 667, 1990; Taff, Bucciarelli & Lattanzi, ApJ 392, 746 1992; Bucciarelli, Taff & Lattanzi, J. Stat. Comp. and Sim. 48, 29 1993). With it almost complete success has occurred with regard to the removal of systematic errors which creep into compilation catalogs as a result of inadequate treatment of catalog-to-catalog systematic errors; they can essentially be eliminated a priori or a posteriori (Bucciarelli, Lattanzi & Taff, in press in ApJ 1994; Taff & Bucciarelli, in press in ApJ 1994). What infinitely overlapping circles does can be briefly described as follows: Let X (x) be the measured (true) value of a standard coordinate, S(x,y) (ε) be the systematic (random) error in x at this point, let w∞ be the infinitely overlapping circle weight, a be the standard deviation of the random error in x, N be the total number of stars in this circle which has radius R, and x0,y0 be the coordinates of the center of this circle.

Gspc-II: A Catalog of Photometric Calibrators for the Second Generation Guide Star Catalog

1998 ◽  
Vol 179 ◽  
pp. 379-380
Author(s):  
M. Postman ◽  
B. Bucciarelli ◽  
C. Sturch ◽  
T. Borgman ◽  
R. Casalegno ◽  
...  
Keyword(s):  
Second Generation ◽  
Sky Surveys ◽  
Star Catalog ◽  
Sky Survey ◽  
Guide Star

The Guide Star photometric Catalog (GSPC-I; Lasker et al. 1988) is an all-sky set of photoelectrically determined BV sequences created to provide photometric calibrators for the Guide Star Catalog (Paper-I: Lasker et al. 1990, Paper-II: Russell et al. 1990, Paper-III: Jenkner et al. 1990). Although the GSPC-I has been the basis of preliminary photometric calibrations for the Digitized Sky Survey (DSS; Doggett et al. 1995), its relatively bright cutoff at about 15th magnitude limits its capability to support calibration of sky surveys, e.g., the new GSC-II (McLean et al. 1996, this volume, p. 431).

scholarly journals The Environments of Markarian Galaxies

1990 ◽  
Vol 124 ◽  
pp. 165-167
Author(s):  
John W. MacKenty ◽  
Brian McLean ◽  
Caroline Simpson
Keyword(s):  
Hubble Space Telescope ◽  
Ultraviolet Excess ◽  
Nuclear Activity ◽  
Space Telescope ◽  
Star Catalog ◽  
Guide Star ◽  
The Relationship ◽  
Peculiar Galaxies

The extensively studied Markarian sample of 1500 ultraviolet excess galaxies contains many Seyfert, starburst, and peculiar galaxies. Using the 20 minute V plates obtained for the construction of the Hubble Space Telescope Guide Star Catalog, we have investigated the morphologies of the Markarian galaxies and the environments in which they are located. This paper reports on the relationship between the types of nuclear activity and the morphologies and environments of the Markarian galaxies.

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