Data sheet modifications for the NAD 83 (NSRS2007) coordinates

Monday, October 1st, 2007

Data sheet modifications for the NAD 83 (NSRS2007) coordinates

This announcement has been superceded. Please click here for the latest information.
The following modifications to the data sheets have been implemented:

• The format of the records for the NAD 83 latitude and longitude and the NAVD 88 Helmert orthometric height have been temporarily changed to keep the same spacing as the previous data sheet. The inclusion of 'NSRS' in the datum tag had moved both fields to the right five places and caused applications which take data sheets as input to fail. The new (temporary) datum tag will now read NAD 83 (2007) and an explanatory note will be added to the data sheet to explain that the datum tag '2007' means 'NSRS2007'.

   Please let NGS know of major impacts to software applications by emailing ngs.readjust@noaa.gov by October 31. The 'NSRS2007' datum tag and subsequent shift in the NAD 83 latitude and longitude and the NAVD 88 Helmert orthometric height fields are scheduled to be implemented on the data sheets on November 1.

• For survey control stations determined 'NO CHECK' by the national readjustment, the published NAD83 coordinate line has been designated 'NO CHECK' (replacing 'ADJUSTED') and the ELLIP HEIGHT line has been designated 'NO CHECK' (replacing 'GPS OBS').
  
  
• The ellipsoid height line has been designated 'ADJUSTED' rather than 'GPS OBS' (except for NO CHECK stations; see above).
  
  
• After further review and analysis NGS decided to leave the Network Accuracies on the data sheet. The Local Accuracies will not be published on the data sheets at this time. NGS is working to update the output format of the Local Accuracies. In the interim, the Local Accuracies are available in Re-adjustment Distribution Format (or “RDF”).
  

	Web site owner: National Geodetic Survey Last updated by ngs.webmaster on Thursday, 20-Dec-2007 17:15:04 EST