The National Geodetic Survey
(NGS) officially releases NOAA Technical Report 50:
Rates of Vertical Displacement at Benchmarks in the Lower
Mississippi Valley and the Northern Gulf Coast.
The report describes the methods and
results of research into recent rates and spatial distribution
of subsidence on benchmarks in the lower Mississippi Valley
and northern Gulf Coast region. The technical report underwent
extensive review by the academic and scientific communities.
Additional issues or questions regarding the report may
be sent to htmod@noaa.gov
and will be addressed by NGS. [Report]
First joint Continuously
Operating Reference Station (CORS) and Water Level Station
in the state of Mississippi -- NOAA
and the University of Southern Mississippi partner in Ocean
Springs. For more information, see [NOAA
Magazine article]
NGS DRAFT Guidelines
for Establishing GPS-Derived Orthometric Heights (Standards:
2 cm and 5 cm) are actively being reviewed.
GPS-derived orthometric heights can
provide a viable alternative to classical geodetic leveling
techniques for many applications but additional requirements
apply and thorough analysis of existing local vertical control
(NAVD88) and local geoid are necessary. See
NOTE on GPS-Derived Orthometric Heights versus GPS-Derived
Ellipsoid Heights.
