There has been tremendous interest nationwide in participating in National Surveyors Week, which runs from March 16-22, 2014. How can you get involved in a way that ensures your efforts will assist the NGS Height Modernization Program? Here’s a quick guide.
Although it would be great to coordinate your efforts with others, it is perfectly acceptable to perform these observations on your own at a time that is convenient for you.
What you will need to participate is a GPS receiver capable of tracking L1 and L2 signals from GPS satellites. This is a requirement of the National Geodetic Survey for submission to OPUS, the Online Positioning User Service. You will also need to locate an NAVD88 bench mark in your area, log four hours of GPS data, take some pictures, and then submit the data and images.
Here are some other tips to help you prepare for and participate in the Reaching New Heights program:
- Go to the OPUS website and read about how OPUS works.
- While at the OPUS website, download the Observer Field Log and see what data you will be expected to submit.
- Check out the NGS website notice regarding the 2014 GPS on Bench Marks Campaign.
- If you have Google Earth on your computer, download DSWorld. This is a free program from the NGS that links their monument data sheet information to make it interactive with Google Earth, allowing you to plot where the NAVD88 bench marks are.
- Download the GEOID12A accuracy estimate (95% confidence) from DSWorld; go to “Plot” then Geoid 12A Accuracy. This will download a .kmz file into Google Earth so you can see those areas that are most in need of observations. The orange areas are the most important, but any observations will help.
- Download the data sheets in your geographic area of interest from DSWorld by going to “Download,” “Data Sheets by,” County and State.” Select your state and county from the drop down menu; don’t type it in. Choose as the type “VERTICAL – NAVD88 ONLY” and “ANY STABILITY,” and select OKAY. DSWorld will report that you are “receiving data.” Once these are plotted in Google Earth they are interactive and you can click on the marks to get their data sheets and recovery information.
- Once you choose your mark, go out and recover it. Many of the marks shown in the database have been lost or destroyed. Some are located in vertical walls or under trees and not suitable for GPS observations. After recovering the mark, you can submit a recovery report through DSWorld by going to “Submit” and Recovery Report.”
- Once your data is accepted by OPUS DB you will get a report back from the NGS, and you will have helped to improve the geoid in your region.
Go out and have some fun by spending a day in the field for a good cause. If you want to help organize National Surveyors Week celebrations in your region, go to the National Society of Professional Surveyors website and check out the “2014 National Surveyors Week Volunteer Kit.”
For more information, contact your local NGS Geodetic Advisor. If your state does not have a geodetic advisor, locate the one that is closest to you.
Spread the word! Together, we can help the NGS improve the vertical component of the National Spatial Reference System.