Yesterday we ran a level run through an NGS monument. Does anyone say we ran levels to describe the same thing? I remember reading that phrase somewhere many years ago. What looks like the original witness post is now mostly obscured by a chain link fence and vegetation. I think it should have a nice orange fiberglass witness post showing it's there. I emailed NGS. Their response appears below.
Re: NGS Monument Preservation
Good Afternoon Mr. ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ,
Thank you for contacting the National Geodetic Survey, (NGS), about this survey mark. I am notifying NGS' Regional Advisor, Denis Riordan, who can provide assistance on the process in its preservation.
He can be reached at: (240) 678-2107 or Denis.Riordan@noaa.gov.
Deborah Brooks
Infocenter
Communications and Outreach Branch
National Geodetic Survey
301-713-3242
ngs.infocenter@noaa.gov
I think that was a very nice response! A picture of the monument appears below.
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That mark AK6895 has a VERTCON vertical value, meaning that it had an NGVD29 elevation that was shifted by an interpolated amount to get a NAVD88 elevation, and was not part of the NAVD88 network adjustment.?ÿ?ÿ So I wouldn't put a lot of reliance on it if you can find a real NAVD88 value instead.
If you can find these nearby disks they would give you 1st order class II NAVD88 values
AK1794, TAFT AZ MARK
AK1796 TAFT RM2
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edit to add data sheet links
Did you file a mark recovery noting the current condition?
https://www.ngs.noaa.gov/surveys/mark-recovery/index.shtml
As Bill said, the vertical on this mark is modeled to NAVD88. Either of the marks he suggested would be much better for accessing the NAVD88 datum. The NGS Regional Geodetic Advisors are quite knowledgeable and responsive. You might want to reach out to Denis. They are great resources.
I must've missed where he mentioned using this as his basis for elevation for his project?
True, he could be on a local or assumed datum and just using this as a turning point or project bench mark with whatever elevation it has in his own datum.?ÿ
That is the only NGS mark he mentioned leaves the possibility that it was the elevation reference. Maybe we will get clarification.
yes we use the phrase "run levels" all the time or better yet "hey you two, go run levels between control and the benchmark." Unless it is near a beach or college campus then the phrase is "Who wants to go run levels with me?"
I don't know if the office filed a mark recovery. It sounds like a great idea because we need to preserve the NGS monument network.
We are verifying and supplementing our vertical control network. We are county surveyors and are using our own network. There's an upcoming road-widening project within an old leg, so we set two new BMs for construction. We did set them outside the construction limits, just in case you were wondering. The NGS monument we ran through was just for a check. I will discuss what you wrote concerning the monument's vertical value with my supervisor.
We should start a thread called "Old Survey Phraseology." A college campus is definitely a fun place for any survey activity; if you can keep the instrument from drifting! A notable experience of mine was a tree survey at a south Florida campus. The horticulture professor wanted us to locate all of her trees, some exotic, for her curriculum. It was just me and my party chief. The professor gave us a tour and identified the less well-known trees. There was this really cool tree from Indonesia called a dynamite tree (informal); it was covered with large thorns. The informal name came from the fact, that when the large seed pods fall and hit the ground, they make a loud popping sound. Another tree, I don't remember the name, had what the professor described as the world's largest hanging fruit. The fruit can weigh as much as sixty to seventy pounds! The inside of the fruit has the consistency of a banana.
It??s probably a Jackfruit. Some South Floridians grow them as ornamentals. ?????ÿ
https://www.sun-sentinel.com/features/fl-fairchild-garden-column-091414-20140922-story.html
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That tree you don't remember the name of, are you sure it wasn't a "Lurker Tree"?
Quite possibly. I forgot to mention the Ylang Ylang tree. Its flowers really do smell like Chanel No. 5.
Please visit https://www.south-florida-plant-guide.com/ylang-ylang-tree.html.
Be careful how you make comments to NGS. the last time I made a similar comment, Ronnie Taylor send me a case of fiberglass witness post and and flapper-sleeve thing you use to drive them with.?ÿ?ÿ
Is the flapper-sleeve thing a fence post driver?
I expect he's talking about a Carsonite post driver.?ÿ It's similar to a fence post driver, but has a narrow rectangular cross-section that fits the fiberglass Carsonite post.
I stopped using the big Carsonites and switched to the Berntsen Thin Line posts.?ÿ Similar to Carsonite but much narrower, so less expensive, easier to store and carry.?ÿ?ÿ
