Undocumented Benchmarks

[BeachBum22]

I think we need a new forum here, called ASK DAVE!

 

Dave, why would organizations (like the U.S. Army Corps of Engineers) set benchmarks and then not list them in the NGS database?

 

In order for them to be useful to local surveyors, don't they have to be documented some place?

 

Can't find any USACE database on the internet, and they don't answer email relating to benchmarks.

 

PIER-3 PIER-2 PIER-1

 

BeachBum22

http://www.benchmarkhunting.com

Just because I can't find it doesn't mean it's not really there.

[Z15]

Many Corps of Engineers marks are not really Bench Marks. Just because they look the same does not make it so nor does that fact that some can be found in the NGS database. Also with many agency's, the survey data is held in the district and not sent on to a central office. You need to find out where the district headquarters is for the area and contact them. Emails often go to the dead zone, so written requests and or personal visits are most productive. I have had to contact the CE hear in Michigan, there are 3 office that have data, Detroit, Duluth and SOO Locks. Then you have to find the right people to ask.

 

All CE property's have these control marks on them and they are referenced to build plans for the Breakwater, seawall etc. They may or may not have elevations on them.

 

Many state and federal agency's never had the time and the forethought to organize their survey data. They were mainly interested in the results of the survey work (mapping etc) and concentrated on that. The survey data was filed and forgot about till another survey was needed and the records were retrieved from archives. For them to computerize all this data today would cost millions if not billions of $$ and man-hours, not to mention that the survey data may not always be consistent with other data of other agency's like NGS or USGS.

 

People today can't always understand why something is not in a database but that takes time and money, the CE was charged with building the pier, seawalls etc and not making computer databases.

 

We were seeking some data in US Forest Service marks several years back. We spent the whole day finding the right office, then had to search thru about 10 file cabinets to find the data. Then is was in a format no one could discern, even the USFS surveyor said it was unreliable and recommended against using it.

 

Mike

Survey Tech (Retired)

 

[This message was edited by elcamino on September 13, 2003 at 09:27 AM.]

[DaveD]

Elcamino is right on with this one. While most posters on this site generically refer to all marks as benchmarks, in fact there are tens of thousands of marks set by numerous Federal, State, local agencies and private companies for many different purposes. The primary purpose of the data maintained by NGS is to form the national framework to which many other survey applications can be related. While we have encouraged these agencies/companies to provide us these data, many do not for a variety of reasons. For example, the Corps of Engineers monitors the movements of large structures such as levees and dams and is responsible for the dredging of navigation channels in major ports and rivers. Surveys such as these often only require what may be called "project coordinates" and do not necessarily need to be even connected to a national system. COE surveyors periodically to monitor the structures or redredge the channel in the same location would use the marks.

 

In addition, many of these marks were established long before the use of GPS at a time when performing survey measurements to the level of accuracy required by NGS would have been beyond the capabilities, needs and requirements of these agencies. Today, with GPS these same surveys can be conducted too much higher level of integrity, and slowly agencies like COE are trying to have their data included in the NGS Data Base. The process of submitting this data is unfortunately, not very user friendly. It is very much more than just send us a listing of stations and their coordinates. To submit even one survey mark requires that the survey have been conducted to a very high level of integrity (1st-Order) and the original data submitted in NGS defined specific computer formats, call "The Blue Book." This process can often add 10-15% of the cost of the original survey; so unfortunately, many groups choose not to send us their data.

[Z15]

Here's a photo I took on one of the USFS marks I mentioned.

You will never find any data for this mark in a database. USFS used it for Nat'l Forest land boundry work and we used it for control for road construction.

 

This project had NGS approval and was done in 1999. The Land Surveyor aka GPS party chief got transferred to another job, the NGS advisor and the region surveyor retired and the project ended up in a dead end file. Present people in charge have no interest in completing the blue booking.

 

 

Mike

Survey Tech (Retired)

 

[This message was edited by elcamino on September 16, 2003 at 05:25 AM.]

[ArtMan]

quote:

---

Here's a photo I took on one of the USFS marks I mentioned.

---

 

Many of us still use slow dial-up connections. I hope I am not out of line in suggesting that when contributors post photos, they please consider bandwidth issues and limit the number of photos posted and also reduce them in size as a courtesy to Luddites like me with 56K (or slower) access. Thanks.

 

Respectfully,

ArtMan

[+Kewaneh & Shark]

As has already been said (here and in previous threads) the NGS is not the only surveying agency in the nation, and the NGS does not have an exclusive on survey data, benchmarks, or benchmark systems. There are many agencies that set marks and most have their own database and system of documentation. Much of that documentation, which usually began before computers or the internet, is still recorded in a paper format.

 

When local surveyors do local work, we generally tie into a local datum using locally accepted and documented benchmarks; city or county benchmarks, not USGS or NGS, etc., unless that type of mark is nearby. Most of the other types of permanent survey marks that benchmark hunters may find in their hunts are documented somewhere, usually on a local level. If benchmark hunters are interested in finding information about local marks, it can be obtained from the County Surveyor or City Construction Services and/or Public Works Departments. Information about other marks can be found with the respective agency identified on the mark itself.

 

Keep on Caching! (and Benchmarking!)

- Kewaneh

[DaveD]

Unfortunately the case cited by Elcamino is all too often the case. I have seen hundreds of high accuracy surveys that were well performed, well monumented and even well documented, only to be trashed when part of all of the local survey or engineering staff leave or offices are reorganized. I wish it were the norm that most Federal, state and local agencies that perform these observations had their own quality databases. Some very notable exceptions notwithstanding, the sad truth is that most organizations concept of a data base is a file drawer filled with paper or a index card file and a much abused map showing the locations of marks, and unless you know how to find that specific office, you would have a difficult time finding information on these marks.

[+unimoggers]

I found a BM off Cricket Hill Raod (aka Rocky Run Road) in Hawley, PA, zip code 18428. But I can't find it on geocaching.com. My coords were 41* 31.996 and 74* 10.342. 1302 feet and 1965 are stamped on the BM. Any suggestions on where to find its name?

[DaveD]

unimogged, I think you have a typo in the longitude of your position. There is no mark at 74*10.342, however, at 75*10.342 you will find U.S. Geological Survey (USGS) benchmark 218 LRP 1965 1302. As with many other USGS marks, this one was never submitted to NGS for inclusion in the National Spatial Reference System. The "218 LRP" should also have been stamped on the mark. The initials LRP are for the survey chief of party in charge of the work, L. R. Pipher.

[+Colorado Papa]

quote:

---

Originally posted by DaveD:

As with many other USGS marks, this one was never submitted to NGS for inclusion in the National Spatial Reference System.

---

Dave, why is it that I find quite a few descriptions with the north/south and/or east/west reversed in the decriptions from the actual loction of the BM? Example:JK0172where description said

quote:

---

IN TOP OF AND 0.3 METER (1.0 FT) WEST OF THE EAST END

---

and it was actually east of the west end.

 

Also, in my area, the Denver-Rio Grande Railroad had north-south tracks through the entire county and the Santa Fe ran had another route east of them. In many descriptions, one or the other railroad is specified, but the coordinates are given for the other line. Example:JK0193

 

1950 Surveyor

[+Colorado Papa]

quote:

---

Originally posted by ArtMan:

suggesting that when contributors post photos, they please consider bandwidth issues and limit the number of photos posted and also reduce them in size

---

ESPECIALLY THE SIZE!! Think that would take care of the bandwidth problem.

 

1950 Surveyor

[DaveD]

Generally, the mark setting/observer would determine these directions with a compass. Like all of us, from time to time they Oops!

[+ScottJ]

I recently found a mark very near a geocache, completely by accident. The marker has been scraped up badly and is completely unreadable except for parts of the USGS name around the outer rim.

 

No benchmark near that location shows up in the database, but this one is shown on the USGS topo (labeled only "BM 999", its elevation.)

 

I assume that this, like the other one you mentioned, was not reported by USGS to NGS for inclusion. Is there any way to find out more about this one, i.e. does the USGS maintain a database anywhere, or is this one pretty much an orphan now?

 

--

Scott Johnson (ScottJ)

[DaveD]

The USGS "data base" is a file drawer with paper data at their office in Rolla, Missouri. Call 573-308-3500 for info on their marks.

[+rogbarn]

quote:

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Originally posted by DaveD:

The USGS "data base" is a file drawer with paper data at their office in Rolla, Missouri. Call 573-308-3500 for info on their marks.

---

 

ummm... Is the file open to the public or only available to USGS personnel? I might make a short road trip if I can get access.

[+GEO*Trailblazer 1]

I talked to The State Surveyor,Rolla Mo., as well as the One for the Federal Lands,Rolla Mo.

They told me that we could get a CD-ROM of all their marks for around $50.00.

I posted this a long while back and it was in those that we can't go back to.I will try and find the #'s again...........somewhere in all this.........

 

I also got the data for the secondary control marks on my Quadrangle,from the BLM in Reston Virginia, which is Missouri's Sister State.

 

Sister State:All States have copies of all their records in another State for protection.

 

WHEN ALL ELSE FAILS

*GEOTRYAGAIN*

TAKE PRIDE IN AMERICA

http://www.doi.gov/news/front_current.html

1803-2003

"LOUSIANA PURCHASE"

http://www.lapurchase.org

"LEWIS AND CLARK EXPADITION"

http://lewisclark.geog.missouri.edu/index

 

Arkansas Missouri Geocachers Association

www.ARK-MOGeocachers@yahoogroups.com

[Wild T2]

I was at the USGS Mapping Center in Rolla in September 2000. There was very little security at that time. I bet things are different now.

 

Here is a link to their web site.

http://mcmcweb.er.usgs.gov/

[+Thack Pack]

I guess it's my turn to ask about a possible undocumented benchmark. In this case it's a reference mark to FZ1958. I posted a photo and the coords on the page for FZ1958. There are enough pictures here that I didn't think I needed to add my own as well.