Z15

All I see is a broken link, no image.

What state is the mark located in????? Also what is the agency name cast (not stamped) onto the disk? 1999 might be to current to show up in a database yet. It may be a project still in progress. meaning not finalized to the point of having the data processed etc.(?)

NGS Bench Marks (elevation points primarily) are coded with a Letter then a series of numbers, usually 1, 2 or 3 digits. NGS Triangulations stations (horizontal control primarily) were named for the land owner if permitted by them or used a local well known name for the area, e.g. Pikes Peak, Flat Top etc. Otherwise the re-con team came up with the name based on guidelines given them by manuals and supervisors. So, if you see a mark that is designated A 34 you can assumed is was Bench Mark set long ago, probably in the 30's. If you find one A 138, it was set years later. The most recent marks set around here were in 1996 in support of USCG & NGS CORS sites and are number in the 300's. USGS marks are somewhat different. The BM's are usually code with a number then the crew chiefs initials, e.g. 36 RTB or named like "TT 31 C" TT stands for Transcontinental Traverse. If you would like to learn more, there are numerous links in the Bench Mark page that will provide much info, this info and more is buried in the many publications that are available on-line. [This message was edited by elcamino on April 27, 2003 at 05:41 AM.]

I agree. Although the disk is gone, you can still get a approx. elevation from the setting and most likely be within a CM + or -. While is may not be good enough for precise leveling work it still has value for some applications especially if not other bench mark is nearby. I found one that was set in a RR culvert and the disk was missing, all that was left was a 1" hole in the concrete abutment and the outline of the disk like in the photo above. No other vertical control was close. Since we were doing a hydraulic survey and 1-2 CM accuracy was satisfactory to the hydraulic engineer, we used it (the headwall as the elevation) for the project. btw-Nothing was being built, just mapping all structures up stream/down stream of a new highway bridge.

The basic difference is what they do. DGPS broadcasts GPS corrections to GPS user (Marine mainly) because is a fixed location where high accuracy is not required. You have a GPS receiver with a DGSP radio receiver. You GPS tracks your position, you also receive the broadcast from the DGPS and it adds the correction to your receiver and more accurate locates your position. In the surveying field we call this RTK (real time kinematic). Most DGPS receivers need only accurate to 5 meters or so although there are highly accurate DGPS receivers but very costly. Also there needs to be a DGPS signal for you to use it, you can go out of radio range. CORS on the other hand collects high accuracy GPS data 24/7, downloads it to a computer which them makes it available for downloading. The equipment you would need to use CORS is very costly ($1000's) related to what you would need ($100's) to use DGPS. CORS is used in the Surveying and other technical profession. A CORS can also be a DGPS if configured to be(although not many are) but it requires more equipment but a DGPS will not be a CORS mainly due to cost. FYI-To set up a CORS station would cost about $35,000 +/-. + a dedicate T-1 phone line, servers and software and the position has to be surveyed for 15 hrs, either continously of in 5.5 hr segments. It has to be precisely positioned to sub-centimeter accuracy and it constantly monitored by computer software to any positional movement. CORS = Very high accuracy surveying DGSP = Marine Navigation mainly [This message was edited by elcamino on April 26, 2003 at 05:30 AM.]

Here is one in a manhole. Although the recovery does not note it, I am aware this was recovered by MDOT within last 5 yrs. DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 6.75 1 National Geodetic Survey, Retrieval Date = APRIL 23, 2003 QK0249 *********************************************************************** QK0249 DESIGNATION - A 2 QK0249 PID - QK0249 QK0249 STATE/COUNTY- MI/MACKINAC QK0249 USGS QUAD - ST IGNACE (1976) QK0249 QK0249 *CURRENT SURVEY CONTROL QK0249 ___________________________________________________________________ QK0249* NAD 83(1994)- 45 50 50.27400(N) 084 43 23.98667(W) ADJUSTED QK0249* NAVD 88 - 177.331 (meters) 581.79 (feet) ADJUSTED QK0249 ___________________________________________________________________ QK0249 LAPLACE CORR- -3.94 (seconds) DEFLEC99 QK0249 GEOID HEIGHT- -35.39 (meters) GEOID99 QK0249 DYNAMIC HT - 177.337 (meters) 581.81 (feet) COMP QK0249 MODELED GRAV- 980,647.2 (mgal) NAVD 88 QK0249 QK0249 HORZ ORDER - FIRST QK0249 VERT ORDER - FIRST CLASS II QK0249 QK0249.The horizontal coordinates were established by classical geodetic methods QK0249.and adjusted by the National Geodetic Survey in February 1997. QK0249 QK0249.The orthometric height was determined by differential leveling QK0249.and adjusted by the National Geodetic Survey in June 1991. QK0249 QK0249.The Laplace correction was computed from DEFLEC99 derived deflections. QK0249 QK0249.The geoid height was determined by GEOID99. QK0249 QK0249.The dynamic height is computed by dividing the NAVD 88 QK0249.geopotential number by the normal gravity value computed on the QK0249.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 QK0249.degrees latitude (g = 980.6199 gals.). QK0249 QK0249.The modeled gravity was interpolated from observed gravity values. QK0249 QK0249; North East Units Scale Converg. QK0249;SPC MI N - 120,792.991 8,176,806.554 MT 0.99993188 +1 38 44.0 QK0249;UTM 16 - 5,079,602.006 676,770.859 MT 0.99998417 +1 38 02.0 QK0249 QK0249: Primary Azimuth Mark Grid Az QK0249:SPC MI N - MACKINAW CITY MUNICIPAL TANK 178 31 46.6 QK0249:UTM 16 - MACKINAW CITY MUNICIPAL TANK 178 32 28.6 QK0249 QK0249|---------------------------------------------------------------------| QK0249| PID Reference Object Distance Geod. Az | QK0249| dddmmss.s | QK0249| QK0736 MACKINAC IS GRAND HOTEL TANK APPROX. 7.5 KM 0862642.3 | QK0249| QK0726 ROUND ISLAND LIGHT APPROX. 8.4 KM 0931116.9 | QK0249| QK0734 MACKINAW CITY MUNICIPAL TANK APPROX. 7.1 KM 1801030.6 | QK0249|---------------------------------------------------------------------| QK0249 QK0249 SUPERSEDED SURVEY CONTROL QK0249 QK0249 NAD 83(1986)- 45 50 50.26683(N) 084 43 23.98582(W) AD( ) 1 QK0249 NAD 27 - 45 50 50.22400(N) 084 43 23.80900(W) AD( ) 1 QK0249 NGVD 29 - 177.373 (m) 581.93 (f) ADJ UNCH 1 2 QK0249 QK0249.Superseded values are not recommended for survey control. QK0249.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums. QK0249.See file dsdata.txt to determine how the superseded data were derived. QK0249 QK0249_U.S. NATIONAL GRID SPATIAL ADDRESS: 16TFR7677179602(NAD 83) QK0249_MARKER: P = PIPE CAP QK0249_SETTING: 17 = SET INTO TOP OF METAL PIPE DRIVEN INTO GROUND QK0249_STABILITY: D = MARK OF QUESTIONABLE OR UNKNOWN STABILITY QK0249 QK0249 HISTORY - Date Condition Report By QK0249 HISTORY - 1954 MONUMENTED MIDH QK0249 HISTORY - 1934 GOOD NGS QK0249 HISTORY - 1956 SEE DESCRIPTION CGS QK0249 QK0249 STATION DESCRIPTION QK0249 QK0249'DESCRIBED BY MI DEPT OF HIGHWAYS 1954 (CTH) QK0249'STATION IS SITUATED 1.5 MILES WEST OF ST. IGNACE AT THE NORTHERN END QK0249'OF THE MOLE QK0249'SECTION COMPRISING THE NORTHERN APPROACH TO THE PROPOSED QK0249'STRAITS OF MACKINAC BRIDGE. QK0249'THIS POINT IS THE ORIGINAL NORTHERN POINT QK0249'DESIGNATING THE CENTERLINE OF THE BRIDGE AND QK0249'WAS ESTABLISHED BY THE MICHIGAN QK0249'STATE HIGHWAY DEPARTMENT. THE MARK IS A 2-BY 48-INCH IRON PIPE QK0249'WITH CAP, QK0249'WITH TRIANGLE AND PUNCHMARK INSCRIBED ON TOP. THIS MARK IS 8 QK0249'FEET BELOW THE PRESENT QK0249'GROUND LEVEL, ACCESS TO SAME BY BRICK-SIDED CIRCULAR QK0249'MANHOLE WITH STANDARD SEWER MANHOLE QK0249'COLLAR AND LID. THE PIPE QK0249'MARKER IS SET IN CONCRETE, WITH JUST THE CAP QK0249'PROTRUDING FROM THE CONCRETE. QK0249'UNLESS TRANSFERRED TO THE BRIDGE LEVEL LATER THIS MARKER WILL QK0249'BE QK0249'INACCESSIBLE AFTER THE BRIDGE IS COMPLETED. QK0249 QK0249 STATION RECOVERY (1934) QK0249 QK0249'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1934 QK0249'1.5 MI W FROM ST IGNACE. QK0249'1.5 MILES WEST OF ST. IGNACE, MACKINAC COUNTY, AT THE NORTHERN QK0249'END OF THE MOLE SECTION COMPRISING THE NORTHERN APPROACH TO THE QK0249'PROPOSED STRAITS OF MACKINAC BRIDGE, THE NORTHERN POINT QK0249'DESIGNATING THE CENTERLINE OF THE BRIDGE, 8 FEET BELOW THE QK0249'PRESENT GROUND LEVEL, ACCESS TO SAME BY BRICK-SIDED CIRCULAR QK0249'MANHOLE WITH STANDARD SEWER MANHOLE COLLAR AND LID. A 2- BY QK0249'48-INCH IRON PIPE WITH CAP, WITH TRIANGLE AND PUNCHMARK INSCRIBED QK0249'ON TOP, SET IN CONCRETE WITH JUST THE CAP PROTRUDING. QK0249'NOTE-- UNLESS THIS MARK IS TRANSFERRED TO THE BRIDGE LEVEL QK0249'LATER, THIS MARKER WILL BE INACCESSABLE AFTER THE BRIDGE IS QK0249'COMPLETED. QK0249 QK0249 STATION RECOVERY (1956) QK0249 QK0249'RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1956 (WNM) QK0249'THE STATION MARK WAS RECOVERED AS DESCRIBED AND FOUND IN GOOD QK0249'CONDITION. THE AREA IS QK0249'STILL UNDER CONSTRUCTION AND THE DESCRIPTION IS ADEQUATE AT THE QK0249'PRESENT TIME. QK0249' QK0249'MR. JACK KENNY, BRIDGE ENGINEER, STATES THAT THE CIRCULAR MANHOLE QK0249'THAT IS BUILT AROUND THE QK0249'STATION MARK WILL BE EXTENDED UP TO THE BRIDGE APPROACH AND THE QK0249'STATION MARK WILL BE PRESERVED. *** retrieval complete. Elapsed Time = 00:00:03

The position you get with a hand held GPS receiver is close but not exact. You can be as much as 100 meters off in position. NOTE-Some hand held have greater accuracy (WAAS compatible) the others and that is reflected by the higher cost Take a look at THIS PAGE , click on the first link in "How do I Start" paragraph and the requirements to do a high accuracy GPS survey. Also note the some positions (Latitude and Longitude) are scaled. That is because the primary purpose of the bench mark was elevation only. You can see from the link that a lot of time and expense is required to determine a precise position for Lat and Long and having precise elevation marks is critical.

There is one LADwho worked on my survey crew last couple of years. He gets into searching out old iron ore mines and survey makers etc. He is involved with a local historical society and that gets him access to all kinds of sites etc. They go out and map old mine sites etc. Whenever he contacts property owners they are willing to let him in. He stops by and BS's with them. He will make a good salesman but is graduating next year as a CE. [This message was edited by elcamino on April 17, 2003 at 05:56 PM.]

quote: STATION RECOVERY (1962)DH2455 DH2455''RECOVERY NOTE BY ALABAMA HIGHWAY DEPARTMENT 1962 DH2455''THE GENERAL LOCATION AS STATED BY O.H.T., 1887 IS GOOD BUT THE DH2455''FOLLOWING MAY AID IN THE FUTURE LOCATION OF THIS STATION. THE DH2455''STATION IS IN A DENSELY WOODED AREA AT THIS TIME, MOSTLY SMALL DH2455''PINE TREES. TRIANGULATION STATION COOSA IS 63.3 FEET NORTH, 40 DH2455''DEGREES EAST OF THIS STATION. THE CORNERS OF THE CONCRETE BLOCK DH2455''OR POST INTO WHICH THE BRONZE DISK WAS PLACED, HAVE BEEN CHIPPED DH2455''OFF BUT THE STATION APPEARS TO BE UNDISTURBED OTHERWISE AND IN DH2455''GOOD CONDITION. NO REFERENCE MARKS WERE FOUND. DH2455 DH2455 STATION RECOVERY (1969) DH2455 DH2455''RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1969 (LFS) DH2455''THE STATION WAS VISITED 2-12-69 AND THE STATION WAS FOUND IN GOOD DH2455''CONDITION. THE CORNERS OF THE 10 INCH CONCRETE POST HAD BEEN DH2455''CHIPPED OFF BUT WAS SETTING UPRIGHT AND SOLID IN THE GROUND. DH2455''NONE OF THE REFERENCE NAILS WERE FOUND. PREVIOUS DESCRIPTIONS DH2455''STATE THAT THE UNDERGROUND MARK IS A BEER BOTTLE MOUTH UPWARD AND DH2455''THE SURFACE MARK IS AN ALABAMA GEODETIC SURVEY DISK SET IN A DH2455''CONCRETE POST. A NEW DESCRIPTION FOLLOWS- 1962 said they found a disk and 1969 said the disk was ALABAMA GEODETIC SURVEY DISK. So it would appear it was set in 1939 since is was the agency disk that was found but that fact was omitted from the description for whatever reason. Thats my take anywho.

quote:DH2455 STATION RECOVERY (1939)DH2455 DH2455''RECOVERY NOTE BY ALABAMA GEODETIC SURVEY 1939 (APR) DH2455''R.E. BUTLER, DIVISION ENGINEER, ALABAMA GEODETIC SURVEY, DH2455''BIRINGHAM, ALA., RECOVERED THE STATION, AND PLACED A BLOCK OF DH2455''CONCRETE OVER THE BOTTLE LETTING IT PROJECT ABOUT 3 INCHES ABOVE DH2455''GROUND AS A MARKER. REFERENCE MARKS WERE NOT FOUND.

Per the recovery notes it was still there in 1993 as found by US Power Squadron. May be buried?

Yes, T is also used. We would use an X, a T or V. The X was the preferred, the T and V when we had little room.. Also not that we would paint them on hard surfaces (roads).

It probably was done because they dug down to set a concrete post but encountered bedrock and used that. I have in fact found some just like this over the years.

For those that are sending reports to NGS for inclusion into the data base. They want to know if a site is suitable for GPS or not. Just because a site is open to the sky, it may not be suitable for GPS. You have to take into consideration of the location. For instance a disk set into the aboutment of a bridge may be clear to the sky but it may be next to impossible to set a tripod on because of local obstructions. When you encounter these points that are not easy to setup on, it should be noted in the description. We searched the database for GPS usable marks and when we went to one we found out we could not use it withour special equipment. We had to get a bipod (did not have one with that team), 2-3 5 gallon pails of sand and sand bags to steady the GPS receiver from the strong winds coming off Lake Michigan. Also had to use 2 Theodilites (Survey Instrument) setup up at 90 deg to each other to monitor the plump of the bypod for the 5.5 observation time required by NGS. Took 2 men instead of normal one person. quote:QK0547 QK0547 STATION RECOVERY (2001) QK0547 QK0547'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 2001 (GEK) QK0547'STATION IS LOCATED ON THE PROPERTY OF MICHIGAN LIMESTONE OPERATIONS, QK0547'INC., PERSONAL PROTECTIVE EQUIPMENT, AND ENTRY PERMIT REQUIRED (NOT QK0547'SUPPLIED BY MLO, INC.). MARK IS DIFFICULT TO OCCUPY W/O SPECIAL QK0547'EQUIPMENT, DUE TO A 3.5 FT HIGH WELDED STEEL RAILING 0.5 FT N OF THE QK0547'STA., AND IS ON THE EDGE OF A BREAKWALL DROPPING OFF TO THE WATER. Another example quote:RL0728 RL0728 STATION RECOVERY (1994) RL0728 RL0728'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1994 (CFS) RL0728'NOTE--NOT SUITABLE FOR TRIPOD SETUP. BRIDGE TO BE REMOVED IN 5 YEARS. RL0728'STATION IS LOCATED IN QUAD 460891, IN ONTONAGON, ALONG STATE HIGHWAY RL0728'64, ON THE RIGHT-OF-WAY, IN THE TOP OF THE NORTH END OF THE SOUTHWEST RL0728'WINGWALL OF THE HIGHWAY BRIDGE OVER THE ONTONAGON RIVER, AND IN THE RL0728'SOUTHEAST 1/4 OF SECTION 25, T 52 N, R 40 W, ONTONAGON TOWNSHIP. RL0728'OWNERSHIP--STATE DEPARTMENT OF TRANSPORTATION. TO REACH FROM THE RL0728'JUNCTION OF STATE HIGHWAYS 64 AND 45 ON THE WEST SIDE OF ONTONAGON, GO RL0728'SOUTH ON HIGHWAY 64 FOR 0.2 KM (0.10 MI) TO THE FAR END OF THE HIGHWAY RL0728'BRIDGE AND THE STATION ON THE RIGHT. STATION IS 11.8 M (38.7 FT) EAST RL0728'OF THE NORTHEAST CORNER OF A CHAIN LINK FENCE, 7.0 M (23.0 FT) RL0728'SOUTHWEST OF CENTERLINE OF HIGHWAY 64, 5.1 M (16.7 FT) NORTH OF THE RL0728'SOUTH END OF WINGWALL OF BRIDGE, AND 0.5 M (1.6 FT) BELOW LEVEL OF THE RL0728'HIGHWAY. [This message was edited by elcamino on April 13, 2003 at 12:14 PM.]

Catcher24 Just a bit of constructive criticism if I may with reports to NGS. The terms " Recovered as described and Recovered in good condition are redundant. The fact that is was recovered and in what condition is already listed in the History. Adding it into the text you are taking up server space. I think they even ask yo not to do this on the web page. quote:NGS QUOTE Note: Text such as RECOVERED AS DESCRIBED, or MARK NOT FOUND, or DESCRIPTION IS ADEQUATE, etc. is not necessary It is not necessary to add this type of extraneous info, that paint will be long gone in a year or less. quote:NC0593'RECOVERED AS DESCRIBED. APPEARS TO HAVE BEEN USED FOR REFERENCE WITHINNC0593'LAST FEW MONTHS AS IT WAS ENCIRCLED BY RED PAINT AND HAD AN ARROW NC0593'POINTING AWAY FROM IT IN A NE DIRECTION. The info about the rails is pertinent info though and is good to note.

That's an aerial target for a mapping flight. That "X" will show up on the photo's and be used for control. There are more out there in the area depending on how large of an area tehy are to cover. That looks to be a pipeline or utility route, is it? Great Lakes Gas Transmission Co hs done work like that thru the UP of Michigan. They establishde GPS control along the pipelines. There was a survey crew from Texas doing the work, at least thier 4x4 subruban has Texas Plates on. I think the company was Wilbros. When I worked for the MDOT we put many of these out there. They were often in groups of of 5 for aerial triangulation. We would put 3 along the main flight route and 1 on each side of the route, called wing shots. We would then onserve these positions with GPS and run elevations to all points. The scope of the work didicated the amount of field survey needed. Many times they just panel exissting control and that it enough to satisfy the mapping. We would often have to set our own points as very few NGS control existed for our needs. Here's a photo of one of our surveys. [This message was edited by elcamino on April 13, 2003 at 08:24 AM.]

A tidal Bench Mark won't look at different that any othe mark. Its just a designation. Those marks are routinely observed for water level monitoring arnd related activities.

Well lets see if I can make it simple but it may not seem simple to those that are unfamilar with surveying operations. On this site and in this forum the term Bench Mark is used as a generic term for all control but the more precise meaning is; A bench mark is a point for which an elevation has been determined. When a Bench Mark is established usualy there is no precise determination of position, only a hand plotted position of a field map is done by the recon team that recovers the mark or establishs it and only if its not already a horizontal control mark. Reason: They are only determining elevation and position is not necessary. The level party does not make position determinations, that requires more precise and time consuming activites. No with that said, you will find marks that were established as Bench Marks that later were also used for horizontal control determinations and vice-versa. Some horizontal were used by the level party. It all boils down to what the scope of the survey was to start with. With modern day GPS things are starting to change rapidly. They are working on perfecting the use of GPS for determining elevlations with relative accuracy. This is a very complex topic (GPS elevations) and many papers have been written on it and available on the NGS website.

It would be a lot easir to just use the description to look for the Azi.

I have found BM's (working for DOT) along RR tracks buried as much as 2 feet. Can be extremely hard to find. RR's are always doing work and many time the grades are rebuilt and the terrain changes buring or destroying the marks. We had a sounding rod (used for soil studies) and drove that into the ground a t the suspect locations. Sometimes were were lucky and often we were not. On occasion GPS helped put us in the ballpark but it was of no use finding the mark, the decription was the only thing that could help. There are some out there I know probably exist but I was tiring of digging or the references no longer existed and where to dig was up in the air.

I agree that it would not be a good idea to do this but its your property so it up to you. Just be darn sure that it is your property. Many a property owner has had a incorrect assumption of where thier property line is. I know of one case where this person owned 80 acres of land in the boonies and it was surrounded by state land. The land had not been surveyed and the owner has an assumption of where his land was. Over a 5 yrs period he erected a very nice log cabin on what he assumed was his land. In the process of inventory of property that local tax agency had aerial photo's taken of the whole county. They noticed the new home that was not on the taz roles not were there any record of building permits. Since the land was bordered and the onwer had constructed a access road over the state land, the state began to investigate and had the section surveyed and sub-divided. Guess what? The land owner had been so arrogant that he figured there was not need for any survey (cost to much $). Well the state contacted (I know the surveyor and he told use this story) to have it surveyed and it was determined the log home was built about 500 ft onto the state land, which had the best view. The guy was screwed. I heard some time later it was resolved, they offered to let the guy keep the land his house was on, about 5 acres but in trade the state would take his other 75 acres. Either that or restore the state land to the way is was before he logged it etc. It went to court and it came out that the owner was negilent because he never got any permits, any survey and cut an road thru state land without any permits etc. Took about 3 yrs to settle... [This message was edited by elcamino on April 04, 2003 at 10:53 AM.]

RESET is supposed to be stamped on the disk per NGS guidelines. That is the only way to ID the new mark. Can it be possible that you find one that does not have it, sure. Since this work is often done by local officals and private sector personell, there can be anomalies.

fyi Railroads are bad area's to be without consent. Some areas they take a dim view of anyone on the RR right of way. There are several reasons they don't want you there, sabotage, liability and safety for you and the railroad. In this area many years back they had labor problems and someone sabotaged the rails (remove the spikes) and many train cars loaded with iron ore derailed. It took them many days and it cost them a lot of money to repair the damage. Securty/maintanence trucks now ride the rails in advance of the train.

US Army 1966-68 (Drafted) Ft Jackson, SC (Preventive Medicine)

A chisled square was made in concrete or rock by taking a chisel and hammer, scribing an outline square about 1". They often put these on bridge abutments, headwalls, ect. USGS was know to use the often and desingated many an UE 25 C for example, UE meaning "Usefull Elevation" [This message was edited by elcamino on April 02, 2003 at 11:09 AM.] [This message was edited by elcamino on April 02, 2003 at 11:12 AM.]