GRAV-D News Archive
NOAA Collaborates With Other Federal Agencies on Airborne Gravity Survey in Western Alaska
August 2009- NOAA's National Geodetic Survey completed a Gravity for the Redefinition of the American Vertical Datum (GRAV-D) airborne survey in western interior Alaska on August 11th, with portions of western interior Alaska area flown. This survey represents a landmark in the GRAV-D initiative, due to the collaboration with two other federal agencies.the Naval Research Lab (NRL) and the US Geological Survey (USGS). The most recent survey work was flown aboard an NRL King Air C-12 aircraft and was the first GRAV-D airborne survey flown on aircraft not belonging to NOAA. NRL proved to be an able partner, and the survey went well. USGS participated in the survey by providing a magnetometer, as well as additional funding to support flights for calibrating the instrument. More collaborative partnering efforts are expected with both agencies in the future.
This collaboration with the US Navy represents another example of how NOAA and other federal agencies are working together to meet common goals, as outlined in Dr. Lubchenco's announcement of July 24, 2009.
See Dr. Lubchenco's NOAA World story.
Socio-Economic Benefits of GRAV-D estimated at $522 Million Annually
June 2009- Leveson Consulting has evaluated the benefits to the US economy provided by NOAA-NGS' National Spatial Reference System, including CORS and GRAV-D. The report was unveiled at a briefing on Capitol Hill and is available online: one-pager and full report. The expected value of GRAV-D (half of which is due to projected improvements in flood plain mapping) is $522 Million dollars annually. The total value of the National Spatial Reference system, without the improvement of the vertical datum through GRAV-D, already exceeds $2.4 Billion annually. Additional information is available from the National Ocean Service and a podcast.
Western and Northern Gulf Coast Survey Completed
May 2009- A massive GRAV-D effort to survey the Gulf coast from the Texas/Mexico border to the Alabama/Mississippi border, partially funded by the Army Corps of Engineers, was completed in mid-May 2009. The multi-part survey was started in October 2008 in response to the need of the Army Corps for future storm preparedness and, thus, a better vertical datum in the Gulf.
University of Texas at Austin Students Experience GRAV-D Operations
March 2009- The GRAV-D team hosted a group of undergraduate students from a geophysics class at the University of Texas (UT) at Austin on the 10th. The students learned about gravity fundamentals and were able to examine the actual GRAV-D instrumentation, while the team and plane were in Austin for the western Gulf of Mexico survey. The students were first given a short informational talk by GRAV-D scientist Dr. Diehl about airborne gravity fundamentals, herself a graduate of the UT geophysics Ph.D. program. GRAV-D Project Manager Dr. Childers then led the students out onto the airport tarmac to examine the GPS stations used in survey operations and Dr. Diehl led them through a tour of the Cessna Citation to examine and discuss the operation of the airborne instrumentation. The experience was enjoyed by all!
GRAV-D Completes Survey of Puerto Rico and the Virgin Islands
January 2009- Flying ~100 hours over the course of nearly 4 weeks, the GRAV-D team has completed both a high-altitude survey (measuring 400 km x 500 km) at 35,000 ft over Puerto Rico and the Virgin Islands, as well a small low-altitude survey nominally at 5,000 ft over the Virgin Islands. The survey was a huge success.
Two New Hires for GRAV-D
January 2009- The program acquired two new team members this month. Dr. Theresa Diehl joined the Silver Spring, MD office as a specialist in airborne gravity data collection and processing. Dr. Diehl completed her Ph.D. at the University of Texas at Austin in August in geophysics, focusing on airborne gravity studies of Antarctic sub-ice geology and tectonics. David Schmerge joined the Table Mountain Gravity Observatory in Boulder, CO with a background in absolute gravimeter operations and water resource monitoring. Schmerge has previously worked for the U.S. Geological Survey and the Arizona Department of Water Resources.
GRAV-D Scientists Attend Annual Geophysics Meeting
December 2008- NGS geodesists put in a strong showing at the American Geophysical Union Annual Fall Meeting in San Francisco, CA. They chaired a session on improving vertical datums through the use of gravity data and made six scientific presentations.
Table Mountain Gravity Observatory Renovations Begin
September 2008- The NGS Observatory for absolute gravimetry at Table Mountain, CO (outside Boulder) has begun renovations of their facility.
GRAV-D Test Survey Completed Around Anchorage, Alaska
July 4-31- The month of July was a busy one for GRAV-D! In an effort to support "Hydropalooza" (the Integrated Ocean and Coastal Mapping (IOCM) initiative in the Kechamak Bay region of Alaska), the National Geodetic Survey took the airborne gravimeter to Anchorage Alaska and flew almost 100 hours, covering a region 400 by 500 km (see plot). This new gravity data will allow NGS to compute a more accurate gravimetric geoid for this region than has ever been done before. This geoid will support VDatum, IOCM and the GRAV-D project.
GRAV-D Project Manager Hired
May 27th- NGS has hired Dr. Vicki Childers as the GRAV-D Project Manager. Dr. Childers joins NOAA after 12 years at the Naval Research Laboratory where she worked as a geophysicist conducting airborne gravity surveys campaigns.
NGS Flies GRAV-D Test Flights in Northern Gulf of Mexico
January 19-Februrary 15- Members of the GRAV-D airborne and terrestrial teams worked together with scientists from Micro-G LaCoste to install and operate NGS' TAGS airborne gravimeter in the northern Gulf of Mexico.
NGS Trains Airborne Gravimeter Operators with Ground Tests
November 15-17- In planning for initial flights in 2008, NGS has trained three preliminary instrument operators, with the help of Micro-G, on the operation of the TAGS unit, and the intial field processing of data from it. In fashion similar to how it was first lab tested at Micro-G , the TAGS unit was mounted in a road vehicle, simulating airplane operation without the cost of actually flying a plane. The training was a success in both dissemintation of operational training as well as highlighting technical difficulties and arriving at solutions to them.
NGS Approves Final Version of GRAV-D Plan
November 14- At a meeting of the NGS Executive Steering Committee, the GRAV-D plan was approved for public release. A final, edited version was made available in PDF form on December 7, 2007. The plan is available for download as a (.pdf) here.
NGS Acquires Airborne Gravimeter
October 25- As part of its dedication to re-defining the vertical datum through a gravimetric geoid, NGS acquired a new Turnkey Airborne Gravity System (TAGS) from the Micro-G/LaCoste company. This new system combines the latest in airborne gravimeter technology with innovative user-friendly operational software and training in the use of both. On October 25th, the new gravimeter was delivered to NGS. Nigel Brady of Micro-G LaCoste came along to teach NGS personnel how to pack and unpack the meter from its delivery crates and give a quick demonstration of the basic operation of the meter (in static mode). Photos from the delivery will be available soon.
NGS Holds Gravity Seminar at Corbin
April 10-11- A small contingent of NGS personnel converged on the Corbin, Virginia facility to share information with one another on various aspects of NGS's involvement in gravity, geoid modeling, heights and vertical datums. Attendees included instrument operators, research scientists, policy experts, programmers and other personnel who all have some connection to gravity, geoid or height issues. Dan Winester began with a demonstration on the set-up and operation of the FG-5 Absolute Gravimeter (see slideshow to the right). Lectures were held over two days by Dan Winester, Dan Roman and Dru Smith, helping to disseminate a combination of field operational issues, gravity and geoid reserach and future plans to the attendees. Tim Niebauer, President of Micro-G/LaCoste attended to educate NGS as to the latest gravity equipment (terrestrial and airborne) and services his company offers. Photos from the seminar will be available soon.
NGS Releases Draft of 10 Year Plan
February 12- The NGS Executive Steering Committee approved the public release of the NGS 10 year plan. That document was the first official announcement by NGS of its intention to re-define the vertical datum of the United States through the combination of GNSS technology combined with a gravimetric geoid model. The 10 year plan can be downloaded in (.pdf) format here. Following that release, work was begun on an official gravity survey plan to support this decision. Eventually, that plan came to be known as "GRAV-D".
