GRACE: from measurement to gravity
Explore the source record for details and available documents.
GRACE↗
Engineering topics
Watkins, Michael
Publications and source records attributed to Watkins, Michael.
Rate Change Observed at JPLM after the Northridge Earthquake
Geodetic time series detemined with the Global Positioning System indicate that the geodetic rate of a permanent site in Pasadena, Califonia (JPLM) changed significantly after the 17 January 1994 Northridge California earthquake.
Northridge↗
The International GPS Service (IGS) as a Continuous Reference System for Precise GPS Positioning
The International GPS Service for Geodynamics (IGS) is an organization which operates under the auspices of the International Association of Geodesy (IAG) and has been operational since January 1994. The primary objective of the IGS is to provide precise GPS data and data products to support geodetic and geophysical research activities.
GPS data geodetic geophysical research↗
Observations of Seasonal Translations Between the Earth's Mass Center and Lithosphere
See document.
Earth's Mass Center↗
High Precision and Real Time Tracking of Low Earth Orbiters With GPS: Case Studies With TOPEX/POSEIDON and EUVE
TOPEX/POSEIDON carries a dual-frequency 6 channel GPS receiver while EUVE has a 12 channel single frequency receiver. Flying at an altitude of 1334 km, TOPEX/POSEIDON performs precise ocean altimetry, which demands the highest possible accuracy in determining the radial orbit component in post-processing. Radial RMS accuracies of about 2 cm were realized using reduced dynamic tracking techniques. In this approach, orbit errors due to force are substantially reduced by exploiting the geometric strength of GPS to solve for a set of stochastic forces. On EUVE, the emphasis was on evaluating real time positioning techniques with a single frequency receiver. The capability for real time 3D accuracies of 15 m in the presence of Selective Availability was shown. This was validated by comparing to a post-processed differential GPS truth orbit believed accurate to about 1 m.!.
Tracking low-Earth orbiters↗