Louisiana Height Modernization 2006
From LSPS
[edit] UPDATE TO NGS Louisiana Height Modernization - 2006
The final published positions for the NGS / FEMA 2006 South Louisiana Height Modernization Project (2006.81) have now been loaded into the NGS database. Positional information is available via the datasheet retrieval function from our website (http://www.ngs.noaa.gov/ then click on "datasheets" link). Users will note that the elevations on the datasheets for these updated marks are the same as what was released in the Adobe "pdf" file from June 21, 2007 (LA 2006-81 Positions - 062107.pdf). This was the file with the "DRAFT" watermarked across the page.
Attached is a FILE containing all of the 2006 project marks broken out by Parish. The file lists the mark designations and PID's to aide users in being able to more easily retrieve the desired marks from the NGS website. One method of retrieving a list of desired marks from the NGS website can be accomplished by copying the desired mark PID's from the file and pasting them into the "PID" box (on datasheet retrieval page), then clicking on the submit button. (By the way, there are a number of free text editors available from the internet that will allow you to select items by column.) Another means to retrieve the 2006 marks within a given Parish would be to use the retrieve by county option. Attached also is a MAP showing the 2006 project area and general location of the control marks.
Users should note that a number of changes have been made in how the datasheets show positional information for marks in southern Louisiana. One of the changes is in dealing with published elevations. If a previously published vertical control mark has not been recently observed, then the previously published orthometric height (elevation) will be superseded. Datasheets for marks not recently updated in southern Louisiana are still available, but are not recommended for use as a vertical control mark without further investigation / observations by the user. The reason for this change is due to subsidence and other factors. Subsidence is known to be occurring at least in a major portion of southern Louisiana, which includes the 2006 project area.
There are two notes on the NGS website pertaining to the publishing of this data and they will provide additional information as to what has been done. Please see our website for notes:
11/06/2008 - Release of new version of database retrieval program
11/06/2008 - Publication of Southern Louisiana Post Katrina Height Modernization Project
Also, be looking for the release of the next geoid model, Geoid09, within the next few weeks on the NGS website. If you have any questions about this project or other topics, please contact me by phone or email. Additional information can also be obtained by calling the NGS headquarters.
Denis Riordan
NGS State Advisor to Louisiana
(225) 578 - 5260 (Office)
(240) 678 - 2107 (Cell.)
