|
Post by SSO JOAT on Mar 9, 2011 10:15:30 GMT -9
(Probably a question for NorthWes...) I stumbled on mark A94 last fall on the Glenn. Upon close examination of the disc, I found that it was first stamped as A84 but then overstamped as A94. Looks like a field error to me. Does this happen often, or is this a "nifty find" in the benchmark world? Attachments:
|
|
|
Post by NorthWes on Mar 10, 2011 10:17:39 GMT -9
Good eye - benchmark stamping errors occur more often than you might think! A small error like this one's not too bad. I've seen an entire line of copy on a disk overstamped with capital XXXXX and the new copy jammed onto the disk willy-nilly. You see - they usually stamp AFTER the mark has been set! I will say this - most marks from the Great Depression surveys of the 1931-35 vintage have the most precise stamping - carefully aligned to be straight etc.
One of the Hawaii marks I recovered recently had the Reference Mark arrow pointing wildly in the wrong direction (they're to point, with a high degree of accuracy, to the triangulation station disk - because they 'refer' to that location). Ooops.
All of these anecdotal remarks lead back to the necessity of reading with attention to detail the official NGS datasheet's recovery notes section. Any oddities (gross stamping errors, wrong directions etc) will be 'enshrined' for all time in those recovery logs.
And yes - the actual coordinates would be pretty cool to add to your log - your sharp eye spotted that disk, but I'll bet the coordinates listed aren't anywhere near the actual location (it being a 'scaled' mark).
|
|
|
Post by SSO JOAT on Mar 10, 2011 19:44:00 GMT -9
Yeah, I have no idea what happened with the waypoint on that one. I always take a well-averaged read from the other benchmarks I've recovered. My area photo even has my GPSr sitting on top of the post while it was averaging. But when I pulled up my GPS datafile that was saved a few days afterward, I have no waypoint in the area of that mark. I remember right where it is, so it will be easy to stop and get the coords, though it will probably have to wait until spring.
There are a number of marks along the eastern Glenn and southern Richardson that I need to get logged. Especially in the spring before everything greens up, I like to keep an eye on the treeline while driving. I've noticed the witness post signs of a dozen marks along my normal driving route. Every once in awhile, I actually stop and go through the process of getting recovery info. Most of them have just been mental notes of where I saw them with the intent of stopping later due to time constraints or weather and traffic issues.
I also need to get after some BM hunting around Sonai. There is a whole list of unrecovered marks in my region.
|
|
|
Post by NorthWes on Mar 11, 2011 12:08:51 GMT -9
Yeah, I have no idea what happened with the waypoint on that one. I always take a well-averaged read from the other benchmarks I've recovered. My area photo even has my GPSr sitting on top of the post while it was averaging. But when I pulled up my GPS datafile that was saved a few days afterward, I have no waypoint in the area of that mark. I remember right where it is, so it will be easy to stop and get the coords, though it will probably have to wait until spring. There are a number of marks along the eastern Glenn and southern Richardson that I need to get logged. Especially in the spring before everything greens up, I like to keep an eye on the treeline while driving. I've noticed the witness post signs of a dozen marks along my normal driving route. Every once in awhile, I actually stop and go through the process of getting recovery info. Most of them have just been mental notes of where I saw them with the intent of stopping later due to time constraints or weather and traffic issues. I also need to get after some BM hunting around Sonai. There is a whole list of unrecovered marks in my region. Try hitting the 'mark' button on your GPS when you see those witness posts in the treeline; it helps for a return journey. I set up my little eTrex with a custom benchmark symbol for those 'mark' moments, just so I know what they were on the download that evening. I'm just like that - way more attention on the roadside than the road - very handy in moose (& deer downstates) country. And yes - there's a slew of unrecovereds in the Sonai; I've done a few and there are a handful of other recoveries out there as well. However - there are lots more just waiting!
|
|