HR: 1340h
AN: C23A-0929    [Abstracts]
TI: Ground-Based Radar Measurements of the Northern Colorado Snowpack at CLPX- II
AU: * Deeb, E J
EM: elias.deeb@geog.utah.edu
AF: University of Utah, Department of Geography, University of Utah 260 S. Central Campus Dr., Room 270, Salt Lake City, UT 84112-9155,
AU: Forster, R R
EM: rick.forster@geog.utah.edu
AF: University of Utah, Department of Geography, University of Utah 260 S. Central Campus Dr., Room 270, Salt Lake City, UT 84112-9155,
AU: Marshall, H
EM: marshalh@colorado.edu
AF: University of Colorado, Institute of Arctic and Alpine Research, University of Colorado Campus Box 450, Boulder, CO 80309-0450,
AU: Rutter, N
EM: n.rutter@sheffield.ac.uk
AF: University of Sheffield, Department of Geography, The University of Sheffield, SHEFFIELD, S10 2TN, United Kingdom
AB: A stationary, laboratory-grade network analyzer (NA)-based (stepped frequency) radar system and a mobile FMCW (frequency-modulated continuous wave) radar instrument both acquired measurements of the Northern Colorado snowpack during NASA's Cold Land Processes Experiment (CLPX-II, February 2007). These ground- based radar measurements were complimented by manual snow samples and detailed scientific snow pit data. This study concentrates on the preliminary comparison of the two ground-based radar systems while incorporating the associated manual measurements (e.g. stratigraphy, temperature/density profile, grain size estimation, etc.) into the interpretation, on three separate days during Intensive Observation Period 3 of CLPX-II. The stationary radar is based on an AgilentŪ PNA series vector network analyzer (N5230A) with a 10 MHz to 20 GHz frequency range. A configurable test set was used which allowed for dual linear polarization combinations (HH, VV, HV and VH) to be acquired with the same antenna configuration. Dual-polarized 2-18 GHz horns were connected directly to the NA test set with high phase stability cables at a height of approximately 2 meters, within the far field and with the ability to adjust the incidence angle from nadir to horizontal. Measurements were made from a tripod, with a boom sweeping over an arc of approximately 3 meters. During the same field campaign, a mobile FMCW radar acquired measurements from 4-18 GHz, at HH/HV and VV/VH polarizations, at incidence angles of 30 and 45 degrees, and at a height of 2.3 meters (far-field). An additional portable radar was mounted at a height of 50 cm and 0 degrees incidence, and can be used to estimate snow depth, stratigraphy, and SWE. UNAVCO provided precision differential GPS equipment (Trimble 5700/R7, base station and rover) for the mobile FMCW radar, and the radar measurement and control software was adapted to sync with the cm-level positions, which were recorded every second. These measurements cover a wide range of sensor parameters; and in addition, the variation of in-situ snowpack properties within these radar footprints are less complicated to characterize, in contrast with air- and space-borne radar footprints. Manual measurements of snow depth, stratigraphy, and snow water equivalent (SWE) were made frequently throughout radar surveys and are also available for comparison. Future research will incorporate LiDAR and Jet Propulsion Laboratories' PolSCAT airborne scatterometer surveys that were flown during CLPX-II. These ground based measurements may be used to simulate the PolSCAT/QuickSCAT equivalent backscatter at 13-14 GHz, in addition to other frequency ranges not currently flown by airborne or satellite-based systems.
DE: 0736 Snow (1827, 1863)
DE: 0758 Remote sensing
DE: 1855 Remote sensing (1640)
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 1895 Instruments and techniques: monitoring
SC: Cryosphere [C]
MN: 2007 Fall Meeting