DaveD

If you use DSWorld you can enter your coordinates to one decimal place. If the mark in question already has an HH2 value then any new positions will be ignored. If you have the right equipment and can provide HH1 quality then that would update an HH2 position, but not an existing HH1. I'm going to assume that at this time you have not used DSWorld. Once you've downloaded the software and brought up the interface on the tool bar along the top you will see "Submit." If you select that you will get a drop-down menu where you can submit photos, recovery info, state/county corrections and hand-held positions. If you select hand-held positions you will be prompted for the station PID and the program will retrieve the existing info so you will see if it already has an HH2 position. If it only has a scaled value then all you need to do is enter the new coordinates and hit submit. The programer, Malcholm Archer-Shee is planning on doing a webinar on how to use this tool for sometime in February. I will be sure to post the info once it's available.

DSWorld is a very powerful tool and even though it's easy to use there are so many tools imbedded in the program it can be a little daunting. I will be working with Malcolm Archer-Shee to have him host a brief webinar on this this program, hopefully sometime during the first part of the 2012. Once we have that scheduled I will post a note here.

I hope that more bench mark hunters will add the coordinates where they found marks that currently have scaled positions. I have read many posts where the mark was found and they comment that the position was "way off" and then never provide the coordinates where they found the mark. Even if the bench mark hunter does not directly submit their values to NGS, I often review the posts and will harvest these data to update the NGS database. Over the past two years I have collected in excess of 25,000 positions from this site to update the database. Even though resource grade GPS is not at the few cm level, the values posted here can provide a significant improvement and be very helpful to aiding NGS improve the quality of data in the National Spatial Reference System. On some occasions I have found where a mark has been found on multiple occasions and coordinates provided by the finder. When there are two or more sets of values that agree with each to a couple of meters this is even more valuable data to update the NGS database.

Thanks for posting these errors. I've send a change directive to the NGS database team. The county corrections should show up within a month.

This mark isn't in the NGS database because like so many of the USGS marks the U.S. Army Corps of Engineers seldom submitted their work for publication by the USC&GS/NGS. In many cases the survey work was not done to meet national geodetic standards and was often defined as local projects that were not even tied to the national reference datums. This has changed since Katrina. Today USACE submits a considerable amount of data to NGS through the On Line Processing User Service (OPUS). You may be able to find some information on this mark by contacting the Corps of Engineers, Jacksonville District, survey office -- Mr. Jeff Navaille -- Jeffrey.L.Navaille@saj02.usace.army.mil

I'm really happy to see that this functionality has been restored. I can continue my efforts to utilize these data to improve the quality and integrity of passive control in the National Spatial Reference System.

I know that station TR2743 looks strange because it has a computed NAD 27 position but only a scaled NAD 83 coordinate. The reason is that the original observations that were used to determine the NAD 27 position were not found when we automated all the triangulation data for the NAD 83 back in the late 70s, early 80s. NGS has a strict policy that we won't publish adjusted coordinates and/or heights unless we have the supporting observations and they meet the required order of accuracy. There were several thousand stations that failed to meet these requirements at the time of the adjustment. Each of these occurances was reviewed by the well named Control Requirements Analysis Profile (CRAP) team. The only reason this station is in the NGS database is that we have accurate leveling so we can publish the height. I've updated the scaled position to an HH1 using the NAD 27 coordinates and a datum transformation program. This is somewhat similar to the missile site survey marks that others posted. The big difference there is that all of the original triangulation observations were turned over to the Army Map Service/Defense Mapping Agency and they remain classified to this day - even though all the missile sites are gone and we can easily reposition them more accurately with GPS.

Thanks to Harry Dolphin for pointing out the incorrectly scaled position of KV0043. Even though the mark appears to be gone, it's been rescaled and the NGS database corrected.

I will try tomorrow.

No disrespect to anyone who posts here, but not all of the images are of the quality and orientation NGS wants in the database. Regrettably there are too many misidentified stations for NGS to just accept all the images and coordinates that everyone holds. Many posts are for intersection stations which (with some modest exceptions) are not a significantly useful part of the National Spatial Reference System anymore, and I hesitate to load pictures for these stations unless there is a historical or cultural significance to the station. The ability to look at the entire station log gives me a way to evaluate the images, ensure they are linked to the correct mark and where provided ensure that the hand-held position is generally correct. I believe the data we have captured in the past will prove to be a valuable resource for anyone looking for these stations in the future. I am sorry that the system adminstrators have made this change.

I have a staff of one (me) that works on this and I just don't have the time to track them down. When the site was easy to use I could spend the time capturing this valuable info, but I have too many things on my plate to do much else.

I am sorry to see that a change has been made to accessing the images from the Gallery by allowing just an enlarged version of the picture. Losing the link to the full station report basically makes this format useless to NGS. By linking to the full station report, in the past NGS has been able to easily and quickly harvest different images and especially updated hand-held positions to add to the NGS database. Over the past couple of years we have added digital images and updated positions to more than 30,000 marks in the National Spatial Reference System. This new realization makes that effort far more time consuming if not impossible and we won't have the resources to work with this potentially valuable information. I am sad to see us lose this resource.

Thanks to 2oldfarts and Harry Dolphin for posting these errors. Corrections have been sent to the NGS database team. Hopefully they will be processed shortly after the end of the month.

Bill93 is correct. While the relationship varies a bit across the country, the difference between NAD 83 and WGS 84 is approximately 1 m each in the horizontal (latitude and longitude) and ellipsoid height components. People often mistake the difference in the reference ellipsoids, Geodetic Reference System 1980 (GRS80) for NAD 83 and WGS 84 for WGS 84 (a little confusing I know) which are sub mm across the North American continent, as the difference in a position realized in the respective reference frames.

Bill93, you are correct that the typical process was to determine an astronomic azimuth (either Solar or Polaris) and then observe the magnetic bearing of the line. In quite a number of cases the local county courthouse had a record book where the surveyors could log in their results each time they did a comparison.

In cases where magnetic stations were set as pairs they provided both the determination of magnetic declination and the difference with a geodetic azimuth (bearing) that surveyors could use to compare their instruments. Where they were set as a single station then their primary purpose was to determine declination.

The "Blue-Booking" process is very rigorous and that is not exactly what I do with all the old USGS data. As some on this board are aware, the USGS information is still in paper format. For many years when they ran horizontal control traverses to support their mapping efforts they would often tie some of our (USC&GS/NGS) bench mark disks so they would have our vertical control and their horizontal information on the same point. When we created the database that supports NSRS these bench marks were given scaled positions because we did not have the USGS observations "Blue Booked." When we created the HH1 & HH2 position categories several years ago the intention was to have a way that we could improve the recovery information for bench marks from the many users of hand-held devices, and this has been a success. A couple of years ago I looked at all the historic USGS data we had in our archives and figured that their old NAD 27 third-order data was certainly equal to if not better than the intention of HH1. Since that time I have collecting their data by region and transforming their NAD 27 values to NAD 83 using the CORPSCON transformation utility and then our program DSWORLD to submit those updated values to the NGS database. These updates are typically updated within a week of the first of each month. Between positions that I harvest from this site, the USGS data and computing values for RMs I typically update about 1,500 scaled positions each month. Hopefully I will be able to complete the transformations of the USGS data during the next two years before my currently planned retirement date. As I mentioned previously there is almost no one at NGS who even knows this data exists or how to read it anymore.

The HH1 positions for both RL0211 and RK0248 were harvested by me from the historic records of the U.S. Geological Survey (USGS). While USGS never officially submitted their data for inclusion in the NSRS, NGS does maintain a nearly complete collection of their old horizontal and vertical control data. The positions that they determined for mapping purposes are of at least third-order accuracy and certainly better than the scaled values. Along with positions provided from this site (as foxtrot xray noted) over the past two years I have been capturing these data so it can be perpetuated before I retire. I regret that when I go no one at NGS will even know we have this data and how valuable it can be. I have also been computing HH1 positions for Reference Marks (RMs) as LSUFan noted. Since the datasheets for most triangulation stations provide both the azimuth and distance to RMs it is a rather simple process to compute the position using the FORWARD utility we have in the NGS geodetic tool kit. Like the USGS data these values are legitimate and superior to scaled positions. Since no one is actually visiting these stations there are no corresponding recovery notes to post. The HH1 post currently leads one to believe that someone actually made some sort of GPS observation at the station and therefore there should be a recovery. We will be changing the designation of HH1 to read something like "The horizontal coordinates have an estimated accuracy of +/- 1 to 3 meters and were established by differentially corrected hand held GPS observations or other positioning techniques of comparable accuracy."

You guys are too kind. This site is a wealth of up-to-date information about many of the marks in the National Spatial Reference System. I do what I can to harvest information (hand-held positions, digital photos etc.) that will be helpful to the various professionals who rely on this marks to support their surveying and mapping efforts. Regrettably identifying marks as destroyed is one of those tasks.

Without other evidence, my best guess is that it's probably a METRO (Washington Metropolitan Area Transit Authority - WMATA) disk. They've set a considerable amount of control to support the rail system and only a portion of it is in the NGS database.

This is the new PID configuration that is being used for marks that are submitted for publication to the OPUS-Database (OPUS-DB). If you go to the NGS OPUS page -http://www.ngs.noaa.gov/OPUS/and select "Published Solutions" you can access the data that is being submitted by surveyors around the country.

The 2010 Center of Population marker was dedicated yesterday -- http://www.commerce.gov/ and OPUS_DB datasheet

These values may be referenced to the Indian Coordinate system which has several zones and I believe is also called the Lambert Conical Orthomorphic Zones. Before they can be converted to latitude and longitude it would be important to know what horizontal datum (e.g. Indian 1960) they are referenced to and what is the unit of measure (e.g. yards, feet, meters etc.)

I will be there along with the NGS Director, Juliana Blackwell as well as the director of the Census.

The U.S. Census Bureau and the National Geodetic Survey will officially dedicate the 2010 national Center of Population commemorative marker in the town of Plato, Missouri at 1 p.m. on Monday, May 9. Anyone who is in the area is very welcome to attend.