A MINIATURE, LOW-POWER STAR TRACKER FOR PRECISION POINTING NANOSATELLITES

被引：0

作者：

Rowen, Darren W. ^{[1
]}

Utter, Alexander C. ^{[2
]}

Dolphus, Richard M. ^{[3
]}

Alcid, Eddson M. ^{[3
]}

机构：

[1] Aerosp Corp, Microsatellite Syst Dept, El Segundo, CA 90245 USA

[2] Aerosp Corp, Digital Commun Implementat Dept, El Segundo, CA 90245 USA

[3] Aerosp Corp, Control Anal Deportment, El Segundo, CA 90245 USA

来源：

GUIDANCE, NAVIGATION, AND CONTROL 2015 | 2015年 / 154卷

关键词：

D O I：

暂无

中图分类号：

TP [自动化技术、计算机技术];

学科分类号：

0812 ;

摘要：

The design of a compact, low-power star-tracker system is presented for attitude determination in nanosatellites where size, weight, and power are at an extreme premium. The system contains up to five CMOS camera modules linked to a shared image-processing board. Frame capture is handled by a Field-Programmable Gate Array (FPGA), which applies a series of filters to mitigate image-sensor artifacts and automatically adjust luminance thresholds. Filtered pixel data is transferred to a low-power PIC microprocessor, which matches the image against a catalog of stars to solve for attitude. This division of processing minimizes the required memory footprint and maximizes the idle time of power-intensive circuits for improved energy efficiency. PIC memory usage is kept within limits by using only a subset of the star catalog based on partitioning of the full catalog into regions that are loaded into memory as needed. The attitude determination algorithm finds the solution that maximizes the number of pixel cluster locations matched to star catalog locations, with the secondary objective of minimizing line of sight residuals; this approach is tolerant to the presence of hot pixels and non-star objects in the image. An attitude quaternion (as well as the measurement geometry matrix) is provided for use in a recursive attitude determination filter (e.g., to blend with gyro data). Test results are presented showing sensitivity as a function of exposure time.

引用

页码：145 / 156

页数：12