GPS MATLAB Toolbox Review - Reprint of the Innovation column of GPS World, Oct. 1998

Avram K. Tetewksy and Arnold Soltz
Draper Laboratory

Article and Detailed Scoring Rules

The Innovation column of the October 1998 issue of GPS World magazine featured a review of four MATLAB-based GPS simulation packages. With GPS World's permission, we are now providing a PDF version of the article on line. Click on the link below to retrieve the article. Due to space constraints, the detailed scoring rules used to assess the packages could not be presented in the magazine. However, we present them here as a PDF file. We have also separately reproduced the tables from the article and they are available as PDF files too. Two corrections have been made to the on-line tables (the tables in the PDF version of the article have not been corrected):

Table 1
Both the Orion and Constell packages require MATLAB 5.x or higher. They won’t run using MATLAB 4.2c

Table 4.3
Point RAIM: Orion does not supply point RAIM, at least they did not at the end of May 1998. 
WADGPS Coverage: Orion does supply WADGPS with a Y-WD score.

Click on the underlined links to view the PDF files: 
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Article (PDF, 723kB)

• Detailed Scoring Rules (PDF, 72kB)
• Tables 1 - 3 (PDF, 61kB)
• Table 4.1 (PDF, 81kB)
• Tables 4.2 - 4.6 (PDF, 66kB)

For futher information about the scoring of the packages, you can consult the authors via e-mail: atetewsky@draper.com and soltz@draper.com.

This Web site is hosted by the Department of Geodesy and Geomatics Engineering of the University of New Brunswick.

This page was last updated on 24 April 1999.
Reprint of the Innovation column of GPS World, Oct. 1998

"Smart" Camera for Precise Mapping and Targeting - NASA Tech Briefs Online, Sept. 1998

Image data can readily be processed to extract coordinates of features.

NAVSYS Corporation, Colorado Springs, Colorado

A "smart" video camera, called the "GI-Eye," generates digital image data that are automatically tagged with georegistration meta-data to indicate the precise position and attitude of the camera when the image was taken. This automatic georegistration streamlines the processing of the digital image data; in particular, it reduces the time needed to correlate common features in different images and enables the derivation, from the image data, of the precise three-dimensional coordinates of features in images.

The GI-Eye includes a Global Positioning System (GPS) receiver, inertial sensors (an accelerometer and a fiber-optic gyroscope), and a digital video camera. The digital image data are recorded in bit-map file format and can be stored on a compact disk read-only memory (CD-ROM) or other personal-computer-compatible mass-data-storage medium for subsequent retrieval. The georegistration meta-data are saved in an Access data base, where they are cross-referenced to the image bit-map filenames to facilitate the retrieval and processing of the image data.

The GI-View software package is designed to facilitate processing of the GI-Eye digital image data and to generate three-dimensional coordinates of features of interest from the image data base (see figure). This software package runs under Windows on a desktop or laptop personal computer. GI-View provides a point-and-click user interface for selection of features from the digital images. When multiple views of the same feature are selected, GI-View automatically computes the three-dimensional coordinates of that feature. The feature coordinates are saved in an Access data base to facilitate the establishment of interfaces with other Windows application programs or with Geographic Information System (GIS) software.

The GI-Eye system has been demonstrated to provide three-dimensional coordinates from the image data to with 1- to 2-meter accuracy at distances of up to 1 km from the camera. For objects that are much closer, the positions of features relative to the location of the camera can be determined to an accuracy of a few centimeters.

The GI-Eye system has been selected by the U.S. Navy for use in an advanced technology demonstration to provide real-time target coordinates on the battlefield. The GI-Eye system is also available for generating GIS attribute databases and providing point coordinates for mapping and surveying.

{An Image (not displayed - in original article at http://www.techbriefs.com/Briefs/Sept98/SBIR0005.html) Containing a Target is overlaid with target information from an object data base in a typical GI-Eye display.} This work was done by Alison Brown and Randy Silva of NAVSYS Corporation for NASA Headquarters under an SBIR contract to develop a GPS/inertial mapping system and for the Defense Advanced Research Program Agency (DARPA) to develop a precise targeting system. For further information, please contact:

Alison Brown NAVSYS Corporation 14960 Woodcarver Road Colorado Springs, CO 80921 Tel.: (719) 481-4877 Fax: (719) 481-4908 E-mail: abrown@navsys.com or access www.navsys.com

Refer to SBIR-0005.