Abstract submission form (e-mail):
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 Author(s):	Daniel R. Roman 
 	
 Institution(s):The U.S. National Geodetic Survey
							
 Paper title:	Improved Modeling of Gravimetric, GPS, and
 		Leveling Data in High-Resolution Hybrid Geoids
							
 Abstract: 	Hybrid geoids are created from gravimetric geoids and 
 		GPS-derived ellipsoidal heights at spirit-leveled Bench	Marks 
 		(GPSBM's). Modeling of the residuals between the GPSBM's and 
 		gravimetric values has been previously accomplished nationally 
 (~ 100 words)	using single values for correlation length and signal amplitude 
 		in Least Squares Collocation (LSC). The most recent high 
 		resolution hybrid geoid (GEOID99) converts heights between the 
 		NAD 83 and NAVD 88 datums at about 2.5 cm accuracy. Results 
 		are discussed for modeling additional residual signal by 
 		iterating the LSC with progressively reduced correlation 
 		lengths and signal amplitudes and by combining multiple 
 		covariance matrices in a single pass. 

 Address of	National Geodetic Survey  N/NGS5
 responsible	Commerce/NOAA/NOS
 author:	
							
 E-Mail:	dan.roman@noaa.gov
							
 Preferences:	[x] oral   [] poster
 							
 Equipment:	[x] overhead  projector   [] slide projector  [] video-beam