Geoid-12A-accuracy_web Market News

How You Can Make a Difference During National Surveyors Week


This year National Surveyors Week will be celebrated March 16-22. Events are being planned by the National Society of Professional Surveyors as well as by state societies, local surveying chapters and individual surveyors. Some of the celebrations under discussion include publicity events, educational events and support of the National Geodetic Survey’s (NGS) Height Modernization Program.

Each of us has an opportunity to participate in National Surveyors Week to whatever level we are able. Surveyors who live in or nearby capital cities or county seats are discussing setting GPS marks, perhaps with the state society logo embossed on the mark, and occupying these marks so that the public and politicians can meet us and learn about what surveyors do. Other surveyors I know have contacted the press, local schools and scout groups to use National Surveyors Week as an educational opportunity to inform the public about what we do and why it is important. They will set up in school yards or other predetermined locations with GPS receivers, total stations and levels to share their love of our profession.

RELATED: Listen to Frank’s interview with NSPS Executive Director Curt Sumner on the NSPS Radio Hour in the 02/24/14 Archive

Finally, but no less important is the occupation of NAVD88 bench marks to help the NGS improve the vertical component of the National Spatial Reference System.

We all use GPS in our daily lives with cell phones and vehicle navigation, in our hobbies and our work. We as a profession, and the public as our clients, depend upon the correct use of GPS for positioning and heights on their projects. The NGS is currently working on a nationwide height modernization program. This program includes many facets including airborne gravity surveys and new geoid models.  But what is needed most for the development of a new height model is actual GPS measurements on NAVD88 bench marks.

Data submitted to the NGS through the On Line Positioning Service (OPUS) shared solutions option will be available for inclusion in the next geoid model (possibly in 2015 or 2016). It will contribute to the accuracy of a new transformation tool that NGS will develop which will relate NAVD 88 to the new vertical datum scheduled for release in 2022.

The NGS like most government agencies has been gutted by recent budget cuts and attrition. They have few field surveyors and through cooperative programs with the various states only 14 state advisors, nine state coordinators and one regional advisor to cover the 50 states and all of the territories. Your participation is vital to this program and will be much appreciated in the future.

For more information on how to help or how to perform OPUS observations, contact your regional geodetic advisor.

How will you be celebrating National Surveyors Week? Share your comments below.

Above: GEOID12A accuracy estimate (95% confidence) in New Mexico, with green representing +/- 3.9 cm and orange +/- 8.8 cm. GEOID12A is the hybrid geoid model used for determining orthometric heights (NAVD 88) with GPS. The accuracy suffers in areas lacking GPS survey data from bench marks. Image courtesy National Geodetic Survey

 

You can help improve everyone’s GPS heights by sharing new GPS survey data acquired on published bench marks. Most valuable are stable 1st- or 2nd-order NAVD 88, located farthest from the green areas, near populated areas, or wherever you suspect the model’s validity. Image courtesy National Geodetic Survey


Leave a Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Current ye@r *