PE&RS March 1996

Cover Image

Eastern Washington State is an area known for its circular irrigation farming. The cover image is a 15” multispectral SPOT image. The depth of information found within multispectral imagery is extracted with image processing techniques. Insets from upper left: 1) subset of the standard SPOT multispectral imagery; 2) Principal Components Analysis produces images displaying the maximum spatial frequency which significantly improves the analyst’s ability to define boundaries and subtle variations in texture and tone; 3) ISODATA unsupervised classification clusters data with similar spectral signatures. The ISODATA classification helps the analyst categorize the fields by crop type, vitality, etc.; 4) the nonlinear edge enhance-ment highlights field boundaries and natural bound-aries normally difficult to automatically identify. Image processing by Joe Messina, Design by Paul Reid.

Peer-Reviewed Articles

275 Commercial High-Altitude Unpiloted Aerial Remote Sensing: Some Legal Considerations
Joanne Irene Gabrynowicz

Some general legal issues raised by using this particular technology in a commercial remote sensing business that collects, processes, and sells data and imagery are addressed.  

279 The Open Skies Treaty: Qualitative Utility Evaluations of Aircraft Reconnaissance and Commercial Satellite Imagery
Matthew Heric, Carroll Lucas, and Christopher Devine

A qualitative analysis of simulated aircraft imagery, at progressively improved resolutions, revealed an exponential increase in Treaty-Specific information content starting with 10-rn resolution.  

285 Film Cameras or Digital Sensors? The Challenge Ahead for Aerial Imaging
Donald L. Light

Area arrays need to be much larger than currently avail-able to image scenes competitive in size with film cameras.  

293 The Evaluation of MEOSS Airborne Three-Line Scanner Imagery: Processing Chain and Results
C. Heipke, W Korn us, and A. Pfannestein

Digital imagery from MEOSS has been successfully used for photogrammetric point determination and automatic object surface generation with standard de-viations of 0.5 pixel in X and Y and 1 pixel in height.  

301 Methods for Computing Photogrammetric Refraction Corrections for Vertical and Oblique Photographs
Maurice S. Gyer

The effects of different atmospheric models, geographic location, time of year, and large zenith angles are il-lustrated in the form of numerical tables and graphs.  

311 Floating Lines and Cones for Use as a GPS Mission Planning Aid
Michel Boulianne, Rock Santerre, Paul-André Gagnon, and Clement Nolette

A photogrammetric method for generating obstruction diagrams for GPS observation sites is presented.  

317 Forest Canopy, Terrain, and Distance Effects on Global Positioning System Point Accuracy
Christopher Deckert and Paul V Bolstad

The mean differentially corrected positional accuracy for all sites was 4.35 metres, with 95 percent of the mean positions estimated within 10.2 metres of the true value.

Software Review
269 ER Mapper 5.1

ASPRS 1996 Annual Meeting
240 Special Forums

Updates
239 GIS
243 Remote Sensing
247 GPS
255 Government
267 Society

Departments
237 Letter
252 ASPRS Board Report
257 Sustaining Members
259 New Members
260 Report: MARJSY 95
264 Board of Directors
268 Image Processing Marketplace
268 Index to Advertisers
292 Instructions to Authors
316 Forthcoming Articles
323 Calendar
325 Classifieds
327 Professional Directory
331 Bookstore
335 Membership Application

Announcements
256 ASPRS Workshops at A/E/C
254 Meeting at A/E/C Systems 96
300 Call for Papers: GIS/LIS 1996
322 Meeting: ASPRS 1996 Annual Meeting, Baltimore
326 Meeting: XVIII ISPRS Congress, Vienna