Raymond and Ivins 1
Remote GPS Networks:Rationale
Carol A. Raymond, Erik R. Ivins
JPL/Caltech
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Rationale for Antarctic Continuous GPS stations and Constraints on Station Architecture
Rationale for Continuous Measurements: Vertical rates are low (typically few cm?) and need for accuracy is
high to resolve gentle gradients Incomplete noise characterization (phase center drifts, biases,
seasonal tropospheric variations, ionosphere, reference frame issues)for data lengths of < 30 days?
Constraints: If rheology is stiff, and loads are ancient, uplift gradients are small If loads are young, uplift gradients might be large. Likely there will be a spectrum of uplift scales that must be
deconvolved to understand their origin in lateral heterogeneity of earth rheology, and/or glacial loading histories of individual drainage basins
Continuous GPS measurements contribute to understanding the Continuous GPS measurements contribute to understanding the interaction between ice sheet history and dynamics, and earth rheology. interaction between ice sheet history and dynamics, and earth rheology. Support time-varying gravity measurements of ice mass change. Support time-varying gravity measurements of ice mass change.
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High precision vertical components are critical for distinguishing competing models
Current results favor recent ice mass change - indicating smaller scale gradients are expected
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Network proposed in 2004 (Raymond et al.) is designed to measure glacioisostatic deformation in region most sensitive to testing models
Donnellan and Luyendyk (1997-2001)
Air Force Seismic Stations (new)
Raymond et al. (1996-2001)
Proposed TAM CGPS Network
continues decadal-length
times series at 4 sites
W12
W1
WAGN occupations
W13
TA
MD
EF
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Proposed Next-Generation Station Architecture
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• Magnetometer package is undergoing lab thermal testing (30 C to -60C)
• Stratospheric balloon tests in October 2004
• Components, software and architecture can be reused for GPS stations
Picosat and UAV System Engineering (PAUSE)
single board computer
Freewave modem
Li-SoCl2 batteries
magnetometer
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Tumbleweed Polar Rover