Ludwig Hempel - Academia.edu (original) (raw)
Papers by Ludwig Hempel
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Annals of Glaciology, 1999
Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system... more Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system for remote-sensing studies of the polar ice caps in Antarctica and in Greenland. It is used to map ice thicknesses and internal layernigs of glaciers, ice sheets and ice shelves, and is capable of penetrating ice thicknesses of up to 4 km. The system was designed and built by AWI in cooperation with Aerodata Flugmeßtechnik GmbH, Technische Umversitat Hamburg-Harburg and the Deutsches Zentrum fur Luft- und Raumfahrt e.V. The system uses state-of-the-art techniques, and results in high vertical (5 m) as well as along-track (3.25 m) resolution. The radar signal is a 150 MHz burst with a duration of 60 or 600 ns. The peak power is 1.6 kW, and the system sensitivity is 190 dB. The short backfire principle has been adopted and optimized for antennae used on Polar2, a Dormer 228-100 aircraft, resulting in an antenna gain of 14 dB each. Digital data recording allows further processing. The qual...
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Hibernate ist der Defacto-Standard, wenn es darum geht, Daten aus einer relationalen Datenbank mi... more Hibernate ist der Defacto-Standard, wenn es darum geht, Daten aus einer relationalen Datenbank mit der objektorientierten Java-Welt zu verbinden. Dabei kann Hibernate seine volle Kraft entfalten, wenn neue Anwendungen von Grund auf zu entwickeln sind. Aber eine Neuentwicklung setzt nicht immer auf der grünen Wiese auf. Oft müssen bestehende Anwendungen integriert oder nachgebildet werden. Hier hilft das Reverse Engineering.
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Summary: During austral summer 1994/95, an extensive program of glaciological, geophysical and ge... more Summary: During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic measurements along a flow line of the Foundation lce Stream was carried out. The collected data are the basis for mass flux determinations in the entrainment area of the ice stream into the Ronne !ce Shelf. In this paper, the collected data and first results will be
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Polarforschung
During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic me... more During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic measurements along a flow line of the Foundation lce Stream was carried out. The collected data are the basis for mass flux determinations in the entrainment area of the ice stream into the Ronne !ce Shelf. In this paper, the collected data and first results will be presented. Dur ing the expedition, 106 seismic soundings were performed to obtain informa tion about ice thickness, water column thickness and the uppermost layered sea bed in the grounding line area of the Foundation !ce Stream. In addition, air borne radio echo soundings (RES) took place over the southeastern part of the Ronne !ce Shelf gaining more widespread information about the icc thickness. The ice thickness data derived from these different methods agree weIl. At the base camp at 83°10.0' S, 59°34.45' W, the supposed position ofthe grounding line, a gravity meter measured the tide induced vertical movement o...
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Journal of Glaciology, 2000
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Journal of Geophysical Research, 2002
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Annals of Glaciology, 1999
ABSTRACT Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo soundi... more ABSTRACT Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system for remote-sensing studies of the polar ice caps in Antarctica and in Greenland. It is used to map ice thicknesses and internal layerings of glaciers, ice sheets and ice shelves, and is capable of penetrating ice thicknesses of up to 4 km. The system was designed and built by AWI in cooperation with Aerodata Flugmeß-technik GmbH, Technische Universität Hamburg-Harburg and the Deutsches Zentrum fuür Luft- und Raumfahrt e.V. The system uses state-of-the-art techniques, and results in high vertical (5 m) as well as along-track (3.25 m) resolution. The radar signal is a 150 MHz burst with a duration of 60 or 600 ns. The peak power is 1.6 kW, and the system sensitivity is 190 dB. The short backfire principle has been adopted and optimized for antennae used on Polar2, a Dornier 228-100 aircraft, resulting in an antenna gain of 14 dB each. Digital data recording allows further processing. The quality of the recorded data can be monitored on screen and as online analogue plots during the flight.
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Annals of Glaciology, 1999
Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system... more Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system for remote-sensing studies of the polar ice caps in Antarctica and in Greenland. It is used to map ice thicknesses and internal layernigs of glaciers, ice sheets and ice shelves, and is capable of penetrating ice thicknesses of up to 4 km. The system was designed and built by AWI in cooperation with Aerodata Flugmeßtechnik GmbH, Technische Umversitat Hamburg-Harburg and the Deutsches Zentrum fur Luft- und Raumfahrt e.V. The system uses state-of-the-art techniques, and results in high vertical (5 m) as well as along-track (3.25 m) resolution. The radar signal is a 150 MHz burst with a duration of 60 or 600 ns. The peak power is 1.6 kW, and the system sensitivity is 190 dB. The short backfire principle has been adopted and optimized for antennae used on Polar2, a Dormer 228-100 aircraft, resulting in an antenna gain of 14 dB each. Digital data recording allows further processing. The qual...
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Hibernate ist der Defacto-Standard, wenn es darum geht, Daten aus einer relationalen Datenbank mi... more Hibernate ist der Defacto-Standard, wenn es darum geht, Daten aus einer relationalen Datenbank mit der objektorientierten Java-Welt zu verbinden. Dabei kann Hibernate seine volle Kraft entfalten, wenn neue Anwendungen von Grund auf zu entwickeln sind. Aber eine Neuentwicklung setzt nicht immer auf der grünen Wiese auf. Oft müssen bestehende Anwendungen integriert oder nachgebildet werden. Hier hilft das Reverse Engineering.
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Summary: During austral summer 1994/95, an extensive program of glaciological, geophysical and ge... more Summary: During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic measurements along a flow line of the Foundation lce Stream was carried out. The collected data are the basis for mass flux determinations in the entrainment area of the ice stream into the Ronne !ce Shelf. In this paper, the collected data and first results will be
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Polarforschung
During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic me... more During austral summer 1994/95, an extensive program of glaciological, geophysical and geodetic measurements along a flow line of the Foundation lce Stream was carried out. The collected data are the basis for mass flux determinations in the entrainment area of the ice stream into the Ronne !ce Shelf. In this paper, the collected data and first results will be presented. Dur ing the expedition, 106 seismic soundings were performed to obtain informa tion about ice thickness, water column thickness and the uppermost layered sea bed in the grounding line area of the Foundation !ce Stream. In addition, air borne radio echo soundings (RES) took place over the southeastern part of the Ronne !ce Shelf gaining more widespread information about the icc thickness. The ice thickness data derived from these different methods agree weIl. At the base camp at 83°10.0' S, 59°34.45' W, the supposed position ofthe grounding line, a gravity meter measured the tide induced vertical movement o...
Bookmarks Related papers MentionsView impact
Journal of Glaciology, 2000
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Journal of Geophysical Research, 2002
Bookmarks Related papers MentionsView impact
Annals of Glaciology, 1999
ABSTRACT Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo soundi... more ABSTRACT Since 1994 the Alfred Wegener Institute (AWI) has operated an airborne radio-echo sounding system for remote-sensing studies of the polar ice caps in Antarctica and in Greenland. It is used to map ice thicknesses and internal layerings of glaciers, ice sheets and ice shelves, and is capable of penetrating ice thicknesses of up to 4 km. The system was designed and built by AWI in cooperation with Aerodata Flugmeß-technik GmbH, Technische Universität Hamburg-Harburg and the Deutsches Zentrum fuür Luft- und Raumfahrt e.V. The system uses state-of-the-art techniques, and results in high vertical (5 m) as well as along-track (3.25 m) resolution. The radar signal is a 150 MHz burst with a duration of 60 or 600 ns. The peak power is 1.6 kW, and the system sensitivity is 190 dB. The short backfire principle has been adopted and optimized for antennae used on Polar2, a Dornier 228-100 aircraft, resulting in an antenna gain of 14 dB each. Digital data recording allows further processing. The quality of the recorded data can be monitored on screen and as online analogue plots during the flight.
Bookmarks Related papers MentionsView impact