Refraction Correction for Radio Echo-Sounding of Ice Overlain by Firn

Radio Echo Sounding of the Greenland Inland Ice

Radio echo sounding has been used for a number of years in the exploration of polar ice such as the inland ice in Greenland and Antarc­ tica. By means of this technique a number of important glaciological and geophysical parameters may be deter­ mined. Examples are ice thickness, bedrock topography and structure, stratification patterns which are used for climate and flow patterns studies, and ...

Instruments and Methods Improved method to determine radio-echo sounding reflector depths from ice-core profiles of permittivity and conductivity

We present a technique that modifies and extends down-hole target methods to provide absolute measures of uncertainty in radar-reflector depth of origin. We use ice-core profiles to model wave propagation and reflection, and then cross-correlate the model results with radio-echo sounding (RES) data to identify the depth of reflector events. Stacked traces recorded with RES near the EPICA drill ...

Instrwnents and Methods Miniature high-power illlpulse transmitter for radio-echo sounding

We have developed a miniature high-power impulse transmitter for radio-echo sounding of glaciers. It features two synchronous second break-down pulse generators operating in a differential configuration. Specifications include bipolar 550 V pulses having rise times less than 2 ns, 512 Hz repetition rate, 180 mA at 10-14 V d.c. operating power, 5 mA standby current and maximum dimension of 12 cm...

comparison of subjective refraction, predicted phoropter refraction (ppr) by zywave aberrometer, and final surgical plan used for laser vision correction

purpose: to study the validity and reliability of subjective refraction, predicted phoropter refraction (ppr) measured by zywave aberrometer, and final surgical plan applied for laser vision correction. methods: this prospective study was conducted on 94 myopic or myopic astigmatic eyes (48 patients) who were candidates for refractive surgery in negah eye hospital from april 2012 to july 2012. ...

Mapping subglacial surfaces of temperate valley glaciers by two-pass migration of a radio-echo sounding survey