I have seen a lot of USACE boundary maps (sometimes covering large areas around a reservoir) on which everything is SPC, bearings and distances. And all of the corners are labeled with SPC coordinates (albeit NAD27, these are all done long before NAD83)
James Fleming, post: 450199, member: 136 wrote: or control for defamation monitoring that confused the county surveyor
I imagine he was confused
Which brings up a question in my mind. If I have a LONG boundary line that has a very BIG difference in elevation, WHICH horizontal ground distance do you use? High/Low/Middle? Seems to me a grid distance solves that uncertainty. But, as I said before I would expect it to be labeled as such in a note on the plat.
John Hamilton, post: 450205, member: 640 wrote: Which brings up a question in my mind. If I have a LONG boundary line that has a very BIG difference in elevation, WHICH horizontal ground distance do you use? High/Low/Middle? Seems to me a grid distance solves that uncertainty. But, as I said before I would expect it to be labeled as such in a note on the plat.
[SARCASM]Which ever one is closest to my measurement.[/SARCASM]
If you want to compare to an early measurement (whether GLO, Texas, or colonial) I suppose you need to approximate the sum of 1-chain or half-chain increments along the actual surface at the varying elevations. That would need an average CSF taking those variations into account.
Bill93, post: 450262, member: 87 wrote: If you want to compare to an early measurement (whether GLO, Texas, or colonial) I suppose you need to approximate the sum of 1-chain or half-chain increments along the actual surface at the varying elevations. That would need an average CSF taking those variations into account.
Yes
aliquot, post: 450134, member: 2486 wrote: You turned in a plat with state plane distances?
Not only have I produced plats with SPC but I have staked the centerline of roads using grid distances (100.013 between stations). All to meet the requirements of the contract. I TRIED to convince the client that what they wanted was ridiculous but they insisted, so they got what they asked for with a BIG note on the plat.
Andy
I did have a SPC job that was at about a 1.0007 scale factor, the client insisted that everything be done in state plane. It included ROW, wetlands, new parcels.....
Lots of explaining on the plat, the acreages of course didn't work at all, the ROW widths had to be shown short, it was a lot of fun.
Andy Bruner, post: 450274, member: 1123 wrote: Not only have I produced plats with SPC but I have staked the centerline of roads using grid distances (100.013 between stations). All to meet the requirements of the contract. I TRIED to convince the client that what they wanted was ridiculous but they insisted, so they got what they asked for with a BIG note on the plat.
Andy
No reflection on you Andy, but that is one of the craziest things I've ever heard of.
MightyMoe, post: 450303, member: 700 wrote: Lots of explaining on the plat, the acreages of course didn't work at all, the ROW widths had to be shown short, it was a lot of fun.
When the client insists on SPC, why not give dual dimensions? 1320.00 SPC (1320.92 Gnd)
I doubt anyone ever cares about SPC area, so just give and label the ground area.
Just this morning I saw a set of construction contract plans from 2012 or so that was done in State Plane, with a CF supplied. SOMEONE was flat-out LAZY to do that. We DO archive our plans in SPC, but they aren't supposed to go out to the bidders that way!
John Hamilton, post: 450201, member: 640 wrote: It was a monument network covering a county. Almost never do anything like a plat, although there are rare occasions...
But, since you mentioned it, why would it be so wrong to do so IF it was plainly stated on the plat? Jim in AZ seems to thing so as well. Not arguing with you, just wondering why it would be so wrong (or, as Jim says, a crime)
I wouldn't call it a crime, but it is unnecessary and confusing to clients. State plane
John Hamilton, post: 450205, member: 640 wrote: Which brings up a question in my mind. If I have a LONG boundary line that has a very BIG difference in elevation, WHICH horizontal ground distance do you use? High/Low/Middle? Seems to me a grid distance solves that uncertainty. But, as I said before I would expect it to be labeled as such in a note on the plat.
The mean, most software will do that for you.
John Hamilton, post: 450205, member: 640 wrote: Which brings up a question in my mind. If I have a LONG boundary line that has a very BIG difference in elevation, WHICH horizontal ground distance do you use? High/Low/Middle? Seems to me a grid distance solves that uncertainty. But, as I said before I would expect it to be labeled as such in a note on the plat.
This is a great point. Original rectangular surveys in Alaska have been reported at "sea level" for decades now, and the Trans Alaska Pipeline ROW (800 miles) is also reported at "sea level" for just the reasons you state. When you've got to perform massive surveys over changing topography, it can be far more effective to report something other than "ground" distances.
Bill93, post: 450307, member: 87 wrote: When the client insists on SPC, why not give dual dimensions? 1320.00 SPC (1320.92 Gnd)
I doubt anyone ever cares about SPC area, so just give and label the ground area.
They were very clear they didn't want double dimensions, and I didn't give SPC area, I showed ground areas.
I did a topo for a irrigation pipeline about 4 miles long this spring. Engineers wanted UTM (feet) so I gave them UTM (feet). I did have a conversation about the actual line being about 20 feet longer than the UTM distances but they seemed to understand that, they do everything in UTM so it all fits together.
Then they needed an easement description for a 1 mile section. I didn't do that in UTM used a ground level projection oriented to north, no way was I going to be on the hook for putting UTM bearings and distances into a recorded title document. Nobody ever called about the pipeline topo and the easement not matching up for the math. So they either understand or didn't check.
I see no problem working in SPC, as long as you include the meta data. Low distortion projections are even better. For the most part, all of my work in Oregon is now done in an Oregon Coordinate Reference System zone.
I have recounted previously my encounter with a very large national firm who after several months of explanation told me that they had not understood SPC at all, and had been using them incorrectly for decades. They told me that they had no idea why they were requiring SPC, and that they were dropping that requirement in future contracts. They were a firm that should have understood and known better. Now, if they don't understand SPC & ground data, are you going to tell me that Joe Property Owner does? The problem here is that we sometimes tend to give the client whatever they ask for, whether it makes sense or not. It is our job as Professionals to educate them about why we think they shouldn't get what they are asking for, but what they need. If we are not doing that we are not performing Professionally. Just last spring I was able to convince another International firm that the mapping standards in their contract were obsolete, having been created circa 1948. They were astounded to discover this and admitted that they did not understand what they were asking for. They paid me to rewrite their requirements. Some Professional Surveyors understand metadata and scale factors, but I can assure you that most, if not all of their clients do.
Jim in AZ, post: 450492, member: 249 wrote: I have recounted previously my encounter with a very large national firm who after several months of explanation told me that they had not understood SPC at all, and had been using them incorrectly for decades. They told me that they had no idea why they were requiring SPC, and that they were dropping that requirement in future contracts. They were a firm that should have understood and known better. Now, if they don't understand SPC & ground data, are you going to tell me that Joe Property Owner does? The problem here is that we sometimes tend to give the client whatever they ask for, whether it makes sense or not. It is our job as Professionals to educate them about why we think they shouldn't get what they are asking for, but what they need. If we are not doing that we are not performing Professionally. Just last spring I was able to convince another International firm that the mapping standards in their contract were obsolete, having been created circa 1948. They were astounded to discover this and admitted that they did not understand what they were asking for. They paid me to rewrite their requirements. Some Professional Surveyors understand metadata and scale factors, but I can assure you that most, if not all of their clients do.
Jim in AZ, post: 450492, member: 249 wrote: I have recounted previously my encounter with a very large national firm who after several months of explanation told me that they had not understood SPC at all, and had been using them incorrectly for decades. They told me that they had no idea why they were requiring SPC, and that they were dropping that requirement in future contracts. They were a firm that should have understood and known better. Now, if they don't understand SPC & ground data, are you going to tell me that Joe Property Owner does? The problem here is that we sometimes tend to give the client whatever they ask for, whether it makes sense or not. It is our job as Professionals to educate them about why we think they shouldn't get what they are asking for, but what they need. If we are not doing that we are not performing Professionally. Just last spring I was able to convince another International firm that the mapping standards in their contract were obsolete, having been created circa 1948. They were astounded to discover this and admitted that they did not understand what they were asking for. They paid me to rewrite their requirements. Some Professional Surveyors understand metadata and scale factors, but I can assure you that most, if not all of their clients do.
You hit the nail on the head Jim!
Most (MOST) of the folks who ask for SPC or UTM, don't really understand either one! I always try and find out what they REALLY want/need, and after explaining the reality of things to them, IF they still want SPC or UTM, then that's what I provide (but at least I tried).
I have had quite a few requests for NAD27 UTM(s) lately, and I finally figured out the reason. "They" were basing all of their "big picture" analysis on 7?« Minute USGS Quadrangles (which in much of the West are still NAD27).
Whatever.
Loyal
Loyal, post: 450515, member: 228 wrote: I have had quite a few requests for NAD27 UTM(s) lately, and I finally figured out the reason. "They" were basing all of their "big picture" analysis on 7?« Minute USGS Quadrangles (which in much of the West are still NAD27).
Whatever.
Loyal
Let me guess, your clients are geologists, right?
Loyal, post: 450515, member: 228 wrote: You hit the nail on the head Jim!
Most (MOST) of the folks who ask for SPC or UTM, don't really understand either one! I always try and find out what they REALLY want/need, and after explaining the reality of things to them, IF they still want SPC or UTM, then that's what I provide (but at least I tried).
I have had quite a few requests for NAD27 UTM(s) lately, and I finally figured out the reason. "They" were basing all of their "big picture" analysis on 7?« Minute USGS Quadrangles (which in much of the West are still NAD27).
Whatever.
Loyal
Much of the databases are still in NAD27 for oil and gas. However, a lot of the info is based on well logs, with the location scaled off the "PLS" from old well plats that are either 660' or 1980' from the section line "wink, wink".
The elevations are often from altimeters.
They are always so "surprised" when the actual P&A well pipe location is sent to them. 😉
