Design and Operation of a Portable, Digital Impulse Radar

Jones, Francis; Narod, B. Barry

doi:10.3189/002214389793701383

Cited by 18 publications

(11 citation statements)

References 17 publications

(29 reference statements)

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“…The 12 MHz system is similar to other non-commercial constructions based on digitizing oscilloscopes (Jacobel and others, 1988; Jones and others, 1989). The receiver is an eight-bit Tektronix model 524A digital oscilloscope.…”

Section: Radar Equipmentmentioning

confidence: 99%

Delineation of a complexly dipping temperate glacier bed using short-pulse radar arrays

et al. 2000

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We have defined the complex bed topography for a section of a small temperate glacier using 50 MHz monostatic short-pulse radar data and a synthetic-aperture array-processing method. The data were collected on a 100 m by 340 m array grid in the upper stem of Gulkana Glacier, central Alaska, U.S.A. The array processing was based on a modified three-dimensional (3-D) Kirchhoff migration integral and implemented with a synthetic-aperture approach that uses sequences of overlapping sub-arrays to generate depth images in vertical planes. Typical sub-array beam patterns are generally <5° at the −6 dB level, giving a flashlight-like searching capability without distorting the wavelet shape. The bed topography was constructed using normal reflections picked from 3-D array depth images. In some instances reflections were imaged outside the data-cover-age area. The bed surface dips steeply, both parallel and transverse to the direction of ice flow. The maximum observed depth is roughly 140 m. The 3-D method resolved bed dips up to 45°. In regions of steepest dip, it improved depth accuracy by 36% compared with raw data, and by 15% compared with standard two-dimensional (2-D) migration. Over 12 dB of signal-to-noise improvement and improved spatial resolution was achieved compared to raw data and 2-D migration. False bottom layering seen in the raw data and in 2-D migrations is not observed in the 3-D array results. Furthermore, loss of bottom reflections is shown by the 3-D migration to be attributable to the dip and curvature of the reflector, and not scattering losses or signal clutter from englacial inclusions.

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Section: Radar Equipmentmentioning

confidence: 99%

Delineation of a complexly dipping temperate glacier bed using short-pulse radar arrays

et al. 2000

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“…Furthermore, they were light enough to be back-portable, and the transmitters were cheap to build (Narod and Clarke, 1994). With the development of low-power microprocessors, it became attractive to design compact radars as if they were computing equipment (Jones et al, 1989).…”

Section: Development and Field Testing Of Improved Drilling Equipmentmentioning

confidence: 99%

A Short and Somewhat Personal History of Yukon Glacier Studies in the Twentieth Century

Clarke

2014

ARCTIC

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Lake in 1961. Virtually all subsequent field studies of Yukon glaciers were launched from this base. This short history attempts to document the trajectory of Yukon glacier studies from their beginnings in 1935 to the end of the 20th century. It describes glaciological programs conducted from AINA camps at the divide between Hubbard Glacier and the north arm of Kaskawulsh Glacier and at the confluence of the north and central arms of Kaskawulsh Glacier, as well as the galvanizing influence of the 1965-67 Steele Glacier surge and the inception and completion of the long-term Trapridge Glacier study. Excluded or minimized in this account are scientific studies that were conducted on or near glaciers, but did not have glaciers or glacier processes as their primary focus.

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“…Four additional profiles were measured in June 1994 where determination of the glacier bed was not possible with the measurements of the first campaign. We used radar devices, which were built following the designs of Jones and others (1989) and Wright and others (1990), i.e. with two output stages which generate inverse pulses.…”

Section: Radar Measurementsmentioning

confidence: 99%

Snow accumulation and ice flow at Dôme du Goûter (4300 m), Mont Blanc, French Alps

et al. 1997

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Glaciological experiments have been carried out at Dôme du Goûter (4300 m a.s.l.), Mont Blanc, in order to understand the flow of firn/ice in this high-altitude Alpine glacierized area. Accumulation measurements from stakes show a very strong spatial variability and an unusual feature of mass-balance fluctuations for the Alps, i.e. the snow accumulation does not show any seasonal patterns. Measured vertical velocities which should match with long-term mean mass balance are consistent with observed accumulations. Therefore, the measurement of vertical velocities seems a good way of quickly obtaining reliable mean accumulation values for several decades in such a region.A simple flow model can be used to determine the main flowlines of the glacier and to propose snow/ice age of core samples from the two boreholes drilled down tο the bedrock in June 1994. These results coincide with radioactivity measurements made to identify the well-known radioactive snow layers of 1963 and 1986. We can hope to obtain ice samples 55–60 years old about 20 or 30 m above the bedrock (110 m deep). Below, the deformation of the ice layers is loo great to be dated accurately.

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Design and Operation of a Portable, Digital Impulse Radar

Cited by 18 publications

References 17 publications

Delineation of a complexly dipping temperate glacier bed using short-pulse radar arrays

Delineation of a complexly dipping temperate glacier bed using short-pulse radar arrays

A Short and Somewhat Personal History of Yukon Glacier Studies in the Twentieth Century

Snow accumulation and ice flow at Dôme du Goûter (4300 m), Mont Blanc, French Alps

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