a proper datasheet?

[StripeMark]

I recovered JE1891, RM 1, RM 2, and the azimuth marker.

 

Reference Mark 2 is also a USGS disc with the NGS PID of JE1892.

 

But look at the datasheet you get for JE1892:

http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=JE1892

 

Can/Should this mark be logged at the NGS site with the standard recovery form?

 

I figured that I would copy over the text paragraph from JE1891 regarding RM 2 and add my own comments.

 

Any thoughts on this?

 

Thanks! -StripeMark

[Bill93]

I think there may be several reasons a PID may not have a published data sheet. The most common seems to be that there is a problem with the data that was submitted for it, and only NGS has access to that information. Although it says at the bottom Hv = DD meaning no descriptive text available, I doubt that it is unpublished merely for the lack of a to-reach description.

 

I think I'd try submitting it on the web entry form along with your other recoveries to see what happens. Shouldn't be any harm in that.

[Papa-Bear-NYC]

There is another possible explanation.

 

I have occasionally noticed that in the "Box Score" a reference mark will be assigned what looks like a PID. When you try to look them up, you get just what you got for this particular reference mark - No Text. My assumption is that these numbers are not really PIDs, but they are entries to a non-public database which allows the NGS to keep track of these marks. But since they are not part of the network of adjusted horizontal control marks, they are not available to the public. In other words since they are just measured from the station mark (distance and direction) and are not part of a closed polygon, they do not qualify as control marks.

 

So far, so good, we've all probably noticed such numbers in Box Scores from time to time.

 

Now my second assumption is that when the laid out this mark and set up reference marks, they found an old USGS mark sitting there and decided to use it as a reference mark. It was never in the NGS database so it just got this "pseudo-PID".

 

I've submitted a few recoveries for non-published marks and guess what - they're still non-published. I think my effort just clogs up their bandwidth and I won't bother trying it again.

 

What you could do is ask Deb or one of the NGS folks who log on here (daveD are you there?) and see if they might offer an explanation.

[StripeMark]

I've seen that also in the "box scores", and noticed that many of the PID's do not match the normal coding for the area, and they bring up no datasheet.

 

But what got me wondering is that the datasheet does recognize this as being "TT 47 B".

[Z15]

When I pulled up the DS this is what I get

 

Pid Name Lat Lon Elev O o Hv

------ ------------------------------ ---------- ----------- -------- - - --

>JE1892 TT 47 B 38 23 32.5/094 14 06.1 275.86 2 3 DD<--no descriptive data

>JE1892 TT 47 B 38 23 32.5/094 14 06.1 275.86 2 3 NN<--no geodetic data

 

 

N No geodetic control at this mark

[Papa-Bear-NYC]

This is interesting and something I have not noticed before. When you bring up the sheet using the URL that stripemark used "http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=JE1892" you just get the one line with the "no Text" code.

 

if you feed the PID into the retreival page as Z15 did "http://www.ngs.noaa.gov/cgi-bin/datasheet.prl?Type=DATASHEETS", you get both lines.

 

And clealy the "No Geodetic Control" is the more significant problem with this mark.

 

I guess the quicky URL (which I generally use) with the "PIDBOX=" just brings up the first line.

 

But back to the question, "No Geodetic Control" may mean what I was getting at - that the position of Reference Mark was just established by a single measurement from the station mark. This is called a "traverse" I think.

[Z15]

They would have measured it more than once but its opened ended. The RM was never occupied and other stations then observed from it, which would be necessary to establish Geodetic Control. The purpose for the Azi and RM's were local and seemed good for the day but technology has advanced so far that today these marks have little use for any high accuracy survey work. They merely serve as a check on the station now. I know of a few stations, in all that remains of any evidence is one remaining RM. All the rest of the station marks were excavated and can never be re-established.

 

A lat and lon on it does not constitute geodetic control. The mark was never run thru any adjustment program.

 

Very often these marks do not check with each other and you will see recovery notes that mention that fact.

Edited August 9, 2006 by Z15

[StripeMark]

This is interesting and something I have not noticed before. When you bring up the sheet using the URL that stripemark used "http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=JE1892" you just get the one line with the "no Text" code.

if you feed the PID into the retreival page as Z15 did "http://www.ngs.noaa.gov/cgi-bin/datasheet.prl?Type=DATASHEETS", you get both lines.

 

I never realized this either. I always use the "quickline" URL. I was wondering how Z15 got that info!

 

Thanks everyone!