Engineering topics
Cunningham, G.
Publications and source records attributed to Cunningham, G..
Determination of Ice Age: A Proposed scheme for a RADARSAT Sea Ice Geopohysical Processor System
We propose a Lagrangian ice motion tracker to follow the trajectory of ice particles at initially fixed grid points in the winter Arctic.
Use of Time Series SAR Data to Resolve Ice Type Ambiguities in Newly-Opened Leads
The backscatter signature of sea ice in newly-opened leads frequently overlaps with that of older and thicker ice types.
Ice Lead Orientation Characteristics in the Winter Beaufort Sea
The directional orientations of leads in the winter ice pack of the Beaufort Sea are studied both spatially and temporally. Data from the European Earth Resources Satellite-1 (ERS-1) Synthetic Aperture Radar (SAR) was used. The SAR data was produced in image form at the Alaska SAR Facility (ASF) with 100 x 100 m pixel resolution. The lead ice pixels, which included all non-multiyear ice, were defined using a simple thresholding of the radar backscatter values. The orientations of the leads covering the Beaufort Sea during the period of January through March of 1992 were derived using a lead skeletonization technique. Results show a strong temporal persistence in the distribution and orientation of the leads during this period.
Determination of the Age Distribution of Sea Ice from Lagrangian Observations of Ice Motion
A procedure for monitoring the local age distribution of the Arctic sea ice cover is presented.
Preliminary results from the ASF/GPS ice classification algorithm
The European Space Agency Remote Sensing Satellite (ERS-1) satellite carried a C-band synthetic aperture radar (SAR) to study the earth's polar regions. The radar returns from sea ice can be used to infer properties of ice, including ice type. An algorithm has been developed for the Alaska SAR facility (ASF)/Geophysical Processor System (GPS) to infer ice type from the SAR observations over sea ice and open water. The algorithm utilizes look-up tables containing expected backscatter values from various ice types. An analysis has been made of two overlapping strips with 14 SAR images. The backscatter values of specific ice regions were sampled to study the backscatter characteristics of the ice in time and space. Results show both stability of the backscatter values in time and a good separation of multiyear and first-year ice signals, verifying the approach used in the classification algorithm.
The primary cosmic ray spectrum above 10 to the 19th power eV
Progress on a re-evaluation of the spectrum of cosmic rays determined with the Haverah Park shower array is described. Particular attention is paid to the reality of some giant showers.
The Outer Planet Mariner Spacecraft
The Mariner Jupiter/Saturn 1977 Spacecraft is designed to conduct a broad range of intensive investigations of the Jupiter and Saturn planetary systems, and of the interplanetary medium from earth to beyond Saturn. The spacecraft design has evolved from earlier Mariners, the Viking Orbiter, and the technology available for implementing long-life, reliable spacecraft designs. A description of the design is presented, and adaptations of that design for Jupiter/Uranus, Jupiter Orbiter, probe carrying, and mini-satellite carrying missions are discussed.