easterly property line dips down to 4300 ft, westerly line climbs to almost 6000ft. This creates approximately 85ppm in the sea level factor. The age old question, do you split the difference and make a "plane" at 5150ft., try to hold the more prevailing elevations, or make a couple of planes. There is always the option to use actually surface distances, which will mean any figure won't close if someone try's to calculate it. This ranch has the local SP meridian running through it, so almost no rotation from state plane to geodetic north, maybe 3-4 minutes on the edges.
I'd use the State Plane Coordinate System, report grid distances and tabulate the Combined Scale Factors at corners along the line. That way, you can use different CSF values for the area calculations of individual parts of the ranch if area is critical. It would be too easy.
Ok, lets ask some questions.
Who needs it?
What kind of structure are they building, that spans this distance?
Who cares?
Why is the survey being done?
If it really matters... You could put it all on grid, and. Add a csf, to each course,
I'm saying this somewhat hypothetically, of course... I've never seen that done before.
A surveyor, i'd guess will have no trouble. Metadata makes it all right, no matter how you decide your plat should show it.
Good post.
Thanks,
Nate
If this is in the Great State of MT, don't forget our fabulous ARM 24.183.1104(1)(d)(xi) and (xii)..... :unamused:
Consider who your client is, and whether they will understand what you report. Kent has a good solution for other surveyors to use. Maybe you could have a closed metes-and-bounds around the parcel @ the mean elevation, and report State-Plane coordinates and the other data on a separate page for the more technical review and/or retracement.
Based on (xi) cited above, I would think you'd show grid distances for each course with the corresponding ground distance in parentheses. TBC should give you that.
Javad LS inverse, always shows both grid and ground.
IF it had one page set to an average gound elev. Factor, it would show that local "grid" and ground. (When that page is set current).
You have a lot of options, most of which have been mentioned.
One more would be to create a custom projection taking advantage of the terrain. An oblique mercator might do the trick. Probably not worth it if this is a one off. Stick with spc and provide a csf table for ground length calcs.
"Consider who your client is"... The bank, the title co reviewer, the next bank, that buys tbe mtg....they don't think about metadata! (wink)
🙂
Nate The Surveyor, post: 427998, member: 291 wrote: Ok, lets ask some questions.
Who needs it?
What kind of structure are they building, that spans this distance?
Who cares?
Why is the survey being done?
If it really matters... You could put it all on grid, and. Add a csf, to each course,
I'm saying this somewhat hypothetically, of course... I've never seen that done before.A surveyor, i'd guess will have no trouble. Metadata makes it all right, no matter how you decide your plat should show it.
Good post.
Thanks,
Nate
It's a boundary for fencing mostly, the more I think about it, I have the data, it's nothing to get a ground distance my computer spits it out anyway, so I may as well do it that way, if the GIS guys can't close it, I don't really care.
There will be lots of side jobs to finish the boundary, some BLA's, vacations, maybe even some new purchases, at least the water is taken care of, already did that. 😉
I've decided to stop doing LDP's, mainly cause people who use my data can't use the dang things. I can make autocad and Trimble speak to each other, but only TM's. Lambert is a whole nuther world. And I can't count the times someone using Petra? and other programs need my data translated, so I've given up, everything now is going to be SP modified. Makes my life easier and it merges nice with all the DOT data spread over the entire state. I will never again do a plat in real State Coordinate distances, it's universally hated.
MightyMoe, post: 428018, member: 700 wrote: It's a boundary for fencing mostly, the more I think about it, I have the data, it's nothing to get a ground distance my computer spits it out anyway, so I may as well do it that way, if the GIS guys can't close it, I don't really care.
There will be lots of side jobs to finish the boundary, some BLA's, vacations, maybe even some new purchases, at least the water is taken care of, already did that. 😉
I've decided to stop doing LDP's, mainly cause people who use my data can't use the dang things. I can make autocad and Trimble speak to each other, but only TM's. Lambert is a whole nuther world. And I can't count the times someone using Petra? and other programs need my data translated, so I've given up, everything now is going to be SP modified. Makes my life easier and it merges nice with all the DOT data spread over the entire state. I will never again do a plat in real State Coordinate distances, it's universally hated.
"I will never again do a plat in real State Coordinate distances, it's universally hated."
AMEN!!!!
Kent McMillan, post: 427995, member: 3 wrote: I'd use the State Plane Coordinate System, report grid distances and tabulate the Combined Scale Factors at corners along the line. That way, you can use different CSF values for the area calculations of individual parts of the ranch if area is critical. It would be too easy.
I agree with Kent on this. What matters is the physical location of the boundary in the field is what matters, how you report the numbers is a secondary issue.
I have a project which is five miles of east to west boundary at about 800' average 20 miles from the coast. I thought of all sorts of schemes and settled on SPC being the simplest way and our GIS folks already have that canned in their software, no need to convert anything. I could give a CF for each Section and anyone could calculate a ground distance close enough for almost all practical purposes in the rough brushy terrain.
Dave Karoly, post: 428034, member: 94 wrote: I agree with Kent on this. What matters is the physical location of the boundary in the field is what matters, how you report the numbers is a secondary issue.
I have a project which is five miles of east to west boundary at about 800' average 20 miles from the coast. I thought of all sorts of schemes and settled on SPC being the simplest way and our GIS folks already have that canned in their software, no need to convert anything. I could give a CF for each Section and anyone could calculate a ground distance close enough for almost all practical purposes in the rough brushy terrain.
I've done SPC plats before, it was something that cropped up in the 1970's and off and on since, but it's not a format I will ever use again unless it's client driven, the last one I did was a disaster........
No one liked it, even the client who requested the dang thing.
Too much distortion......
Rankin_File, post: 428004, member: 101 wrote: If this is in the Great State of MT, don't forget our fabulous ARM 24.183.1104(1)(d)(xi) and (xii)..... :unamused:
Nah, not in the great state of MT, lol, and no offense but that MSP system,,,,,,,,,,,,,,,,,:eek:
MightyMoe, post: 427985, member: 700 wrote: 5150
5150 is police code for an escaped psychiatric patient. It is also the name of Eddie Van Halen's studio. In 1983 the 5150 Studio was built;
Brad Ott, post: 428078, member: 197 wrote: 5150 is police code for an escaped psychiatric patient. It is also the name of Eddie Van Halen's studio. In 1983 the 5150 Studio was built;
Opps!!!
maybe make an even 5000
MightyMoe, post: 428018, member: 700 wrote: I will never again do a plat in real State Coordinate distances, it's universally hated.
By whom? Surely not by land surveyors assuming that you provide CSF values and even a worked example along the lines of :
Surface Distance = Grid Distance / CSF
Grid Distances are a good choice if a surveyor is going to be stingy about which points on the plat he provides coordinates for since simple COGO with Grid Bearings and Grid Distances will easily fill in the missing pieces.
Kent McMillan, post: 428082, member: 3 wrote: By whom? Surely not by land surveyors assuming that you provide CSF values and even a worked example along the lines of :
Surface Distance = Grid Distance / CSF
Grid Distances are a good choice if a surveyor is going to be stingy about which points on the plat he provides coordinates for since simple COGO with Grid Bearings and Grid Distances will easily fill in the missing pieces.
Grid distance= Surface Distance/DAF
MightyMoe, post: 428094, member: 700 wrote: Grid distance= Surface Distance/DAF
I'll bite, what's a DAF? The larger point would be that on a project where the CSF varies considerably, If the Surface Distances were computed from Grid Distances using a project average CSF, that won't really express the relationship between Surface Distances and Grid Distances. What you end up annotating the map with are Surfaceish Distances.
On the other hand Grid Distances are unambiguous and independent of the heights of the stations at the endpoints of the line.
I dunno Mighty, like you say, it's an "age old problem" (computer age that is).
There are many ways to DO IT, ALL of which have drawbacks.
I have a old project that re-emerges every few years, that covers ~40 sq. miles, and has nearly 6000 ft. of relief. Many years ago, I developed an LDP that has a developed (developable) surface of 10,000 NAVD88. There are points 2,000+ feet higher, and some 4,000 feet lower, but the "sweet spot" (where MOST of the activity was/is), stays within a few hundred feet (vertical) of the 10k contour.
Meta data is your only hope, record EXACTLY what you DID (right, wrong, close enough, whatever), and the next surveyor (assuming he/she isn't an idiot), will love you for it.
Loyal