No recovery since 1947 but HD_HELD1 coords?

[+HotRod205]

I must be confused on what "HD_HELD1" means, could someone explain this to a noob?

 

DH0947 *CURRENT SURVEY CONTROL

DH0947 ___________________________________________________________________

DH0947* NAD 83(1986)- 33 24 19.86 (N) 086 52 27.27 (W) HD_HELD1

DH0947* NAVD 88 - 207.619 (meters) 681.16 (feet) ADJUSTED

 

Yet the only reported recovery is 1947, and I doubt they had a GPS receiver then...

 

I was thinking HD_HELD1 & HD_HELD2 were actual readings taken at the mark, is that not correct? And if it was actual readings, why isn't there a recovery note?

[Difficult Run]

Looks like this mark has been given an adjusted horizontal position, but not accurate enough to be bluebooked by the NGS.

Its denoted as a triangle on the USGS map, which suggests its a traverse or triangulation station. Same for DH0946, which is 0.4 mile west.

The NGS probably came along in 1947 and ran a level line, using these existing marks.

 

~ Mitch ~

[2oldfarts (the rockhounders)]

I must be confused on what "HD_HELD1" means, could someone explain this to a noob?

 

DH0947 *CURRENT SURVEY CONTROL

DH0947 ___________________________________________________________________

DH0947* NAD 83(1986)- 33 24 19.86 (N) 086 52 27.27 (W) HD_HELD1

DH0947* NAVD 88 - 207.619 (meters) 681.16 (feet) ADJUSTED

 

Yet the only reported recovery is 1947, and I doubt they had a GPS receiver then...

 

I was thinking HD_HELD1 & HD_HELD2 were actual readings taken at the mark, is that not correct? And if it was actual readings, why isn't there a recovery note?

 

HD HELD1 means that the coordinates are from a Hand held GPSr. Even though there are no official NGS recoveries since 1947 the NGS acquired these coordinates (most likely from photographic sources and/or from someone relating them to the NGS) and updated the datasheet.

 

John

[DaveD]

The designation HH should not be taken literally to mean that someone went to the mark in question with a hand-held GPS receiver, but rather that some form of observation has been made to allow NGS to update a previously scaled value with something that should have more integrity. This could come from several sources:

 

1. Over the pass several years I have captured almost 10,000 hand-held positions from this site for bench marks with scaled values and had them updated in the NGS database - even though no recovery may have been submitted by the person who recovered the mark.

 

2. Reference Marks (RMs) for triangulation stations that are also vertical control points and previously had scaled positions usually have sufficient information to determine their coordinates from the data in the "box score" of the datasheet. As time as permitted, I have computed these values and updated the coordinates in the database. This does not require that the mark have been visited.

 

3. Finally, the U.S. Geological Survey (USGS) during the years that they were actively engaged in field surveys to support their national mapping efforts conducted horizontal surveys on thousands of points. In addition to their own marks they often performed observations to USC&GS/NGS bench marks. Again as time as permitted, I have reviewed the USGS data holdings in the NGS archives and captured their values and updated the NGS database.

 

Since the HH (1 & 2) are defined to assist in the recovery of these marks and not for survey control I have felt that making these data available can be of value to the surveyors and others who rely on the data in the National Spatial Reference System.

[Difficult Run]

Thanks Dave!

 

Sounds like my assumptions were correct, but you did a much better job of explaining it.

 

~ Mitch ~

[+HotRod205]

Thanks! Excellent info!

[+Black Dog Trackers]

DaveD - what about this case in which TillaMurphs' in-person hand held coordinates are better (as evidenced here) than what is on the datasheet as HD_HELD1?

[+LSUFan]

 

1. Over the pass several years I have captured almost 10,000 hand-held positions from this site for bench marks with scaled values and had them updated in the NGS database - even though no recovery may have been submitted by the person who recovered the mark.

 

Since the HH (1 & 2) are defined to assist in the recovery of these marks and not for survey control I have felt that making these data available can be of value to the surveyors and others who rely on the data in the National Spatial Reference System.

 

Thanks for taking the time to share the information with us, Dave. Knowing that now, I will be extra sure to include HandHeld 2 coordinates in all of my future geocaching logs (as well as NGS reports) on marks with scaled coordinates.

 

I've been kinda hit-and-miss on doing that.

[+HotRod205]

I will be extra sure to include HandHeld 2 coordinates in all of my future geocaching logs (as well as NGS reports) on marks with scaled coordinates.

 

How do we do that? Just put them in the description submitted or is there another way?

[+LSUFan]

I will be extra sure to include HandHeld 2 coordinates in all of my future geocaching logs (as well as NGS reports) on marks with scaled coordinates.

 

How do we do that? Just put them in the description submitted or is there another way?

 

Yes, just put them in the description. However, if it is a recovery report submitted to the NGS directly (not on gc.com), remember to convert to the HDDDmmss format.

 

Here is an example of how I do it, but the gurus here may have a lot better ways.

 

NGS log

 

Geocaching log

Edited July 20, 2010 by LSUFan

[wister6813]

Beginning a few years ago, I was listing the HH2 coordinates in the description. Then about 18 months ago I switched to a .gpx file submission with the coordinates. Initially the file was submitted to the NGS through MRAS via an e-mail (see this thread).

 

Now I use the DSWorld program from the NGS website. The submission can be a single location, or multiple locations. Generally I store locations in a file until I have 30-40 points, then submit the group. Garmin's MapSource program is used to store the points and to create the .gpx file. The process is painless.

 

Bob

[+billwallace]

A couple of weeks ago my daughter and I went on a speed run and found about 29/50 along Jolon Road in Monterey county, Ca - YEAY!!

 

I have been lazily logging them on GC.com (lazy is the operative word here) and included my found coordinates to 2 decimal places (seconds). I thought about it a bit and said 'well its only a GC log, I'll do it right when I log to the NGS'. I finished up my GC logs and started in on the NGS logs. I typically look to see if there is a recent recovery first and much to my surprise the PIDs I logged a week ago all have HH1 coordinates that match my GC logs. I don't think my Colorado has suddenly become that accurate. Anyway ... perhaps there is an automated process now that is pulling the coordinates off GC logs and determining the accuracy by the resolution used when we post them. I went back and edited all those logs and rounded correctly.

FV0218
FV0219
FV0220
FV0221
FV0222
FV0223
FV0224
FV0767
FV0769
FV0770
FV0771
FV0773
FV0774
FV0946
FV0948
FV0950
FV1823
FV1951
GU2406
GU2407
GU2413
GU2416
GU2417
GU2418
GU2887
GU4310
GU4311
GU4312
GU4313