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CONVERSION
TECHNIQUES
The use of GPS data and a high-resolution geoid model (Geoid99) to estimate accurate GPS-derived orthometric heights will be directly associated with the
implementation of NAVD
88. It
is important that users initiate a program to convert their products to NAVD 88. The conversion process is not a difficult one, but will
require time and
resources. There will be several
different conversion techniques
available. The technique used will depend on the accuracy requirement of the user, I.e.,
procedures developed
for conversion of less accurate GIS/LIS
products will be different than procedures developed for conversion of USGS NGVD 29 published height values.