Loyal, post: 455594, member: 228 wrote: Well I thought that I made that pretty clear.
The OFFICE (or Field Theo) coordinate is overridden by the FOUND Coordinate. Basically the Theo (Office) generated "block" MOVES to the FOUND Coordinate. This has the effect of updating all the other coordinates within that block/survey.
Inasmuch as Monuments Control over Bearing & Distance, the ??Record Bearing & Distance? only serves to help me Find the Monuments that Mark the Corners. Once I have Found the Corners, then I want to provide a trail of spatial breadcrumbs (footsteps) for the Next guy to follow. The formal projection parameters serves that purpose (inasmuch as everything is tied to the NSRS via the CORS). Because the LDP Parameters are on the my PLAT, anyone wishing to do so, can easily generate Lat/Lon, State Plane, or UTM Coordinates on any or all of said Corners, without having to reverse engineer anything.
Now there ARE cases where I might wish to generate ??PLSS DATUM True Bearings & Distances? between the several Corners, and the Lat/Lon/Eh on each Corner (monument) is all that I need to do that. I will admit at this point, that I don't [usually] return Ellipsoid Heights on all Plats (even though I probably should).
Loyal
Sorry for being so dense, but that sounds to me like your doing it in your CAD program using move, rotate, and maybe scale.
How are you updating your coordinates in the field so you can continue searching for found corners? It doesn't sound to me like you're using your GPS to help navigate you to theoretical calculated corner positions.
I put the Lat Long coordinate on my point of beginning. The next guy can figure the Lat Long from that, though I don't know why anyone would calculate Lat Longs unless they were using a hand held GPS.
How does another Surveyor use the elliposid height? Are your surveys done in State Plane?
Man talking to you I get deeper and deeper into a hole of misunderstanding. I'm probably too dumb to have an intelligent conversation with. You're into something I've never heard of before.
Skeeter1996, post: 455597, member: 9224 wrote: Sorry for being so dense, but that sounds to me like your doing it in your CAD program using move, rotate, and maybe scale.
How are you updating your coordinates in the field so you can continue searching for found corners? It doesn't sound to me like you're using your GPS to help navigate you to theoretical calculated corner positions.
I put the Lat Long coordinate on my point of beginning. The next guy can figure the Lat Long from that, though I don't know why anyone would calculate Lat Longs unless they were using a hand held GPS.
How does another Surveyor use the elliposid height? Are your surveys done in State Plane?
Man talking to you I get deeper and deeper into a hole of misunderstanding. I'm probably too dumb to have an intelligent conversation with. You're into something I've never heard of before.
Well I do carry a Laptop in field (in the truck), and have since the mid-1980s (although the early ones I had didn't support CAD).
NAD83 Latitudes and Longitudes TIE all georeferenced Coordinate Systems TOGETHER, so that you can change from one to another without breaking a sweat. A formally defined LDP is no different in that regard than SPC or UTM.
Ellipsoid heights allow you to compute distances (horizontal) at whatever height you please, or mark-mark slope distances if you care about that (which sometimes comes in handy).
The METHOD that I have been describing works for BOTH RTK and Total Station field work (even handheld I suppose if that's your preference).
Loyal
Loyal, post: 455594, member: 228 wrote: Well I thought that I made that pretty clear.
The OFFICE (or Field Theo) coordinate is overridden by the FOUND Coordinate. Basically the Theo (Office) generated "block" MOVES to the FOUND Coordinate. This has the effect of updating all the other coordinates within that block/survey.
Inasmuch as Monuments Control over Bearing & Distance, the ??Record Bearing & Distance? only serves to help me Find the Monuments that Mark the Corners. Once I have Found the Corners, then I want to provide a trail of spatial breadcrumbs (footsteps) for the Next guy to follow. The formal projection parameters serves that purpose (inasmuch as everything is tied to the NSRS via the CORS). Because the LDP Parameters are on the my PLAT, anyone wishing to do so, can easily generate Lat/Lon, State Plane, or UTM Coordinates on any or all of said Corners, without having to reverse engineer anything.
Now there ARE cases where I might wish to generate ??PLSS DATUM True Bearings & Distances? between the several Corners, and the Lat/Lon/Eh on each Corner (monument) is all that I need to do that. I will admit at this point, that I don't [usually] return Ellipsoid Heights on all Plats (even though I probably should).
Loyal
What software are you using that gives you the LDP parameters. I can only find residual data in my Trimble DC.
NGS once wrote a program to process static GPS. It was pretty tough to use, but it output all kinds of stuff. They were heavy into modeling antenna characteristics back then. I threw those manuals away the second I got out of there. They were in outer space and couldn't relate to what an everyday surveyor needed to know or even need to know.
I'm beginning to think you're in the Black ops arena.
Skeeter1996, post: 455602, member: 9224 wrote: What software are you using that gives you the LDP parameters. I can only find residual data in my Trimble DC.
NGS once wrote a program to process static GPS. It was pretty tough to use, but it output all kinds of stuff. They were heavy into modeling antenna characteristics back then. I threw those manuals away the second I got out of there. They were in outer space and couldn't relate to what an everyday surveyor needed to know or even need to know.
I'm beginning to think you're in the Black ops arena.
I'm not using any "software" to generate LDP Parameters (unless you count the "reduction to sea level algorithm" that I wrote for my HP41 back in the 1970s).
You need to go back to Shawn's LDP articles, there is no black magic involved, just a basic understanding of mapping projections.
Loyal
Loyal, post: 455604, member: 228 wrote: I'm not using any "software" to generate LDP Parameters (unless you count the "reduction to sea level algorithm" that I wrote for my HP41 back in the 1970s).
You need to go back to Shawn's LDP articles, there is no black magic involved, just a basic understanding of mapping projections.
Loyal
So you're not even using RTK? Now I understand why you never do site calibrations. Now I feel like I've been lead along like a dating forum.
I still respect you Loyal you're a smart man.
Skeeter1996, post: 455606, member: 9224 wrote: So you're not even using RTK? Now I understand why you never do site calibrations. Now I feel like I've been lead along like a dating forum.
I still respect you Loyal you're a smart man.
I have been RTK since the mid-90s, and that's EXACTLY why I do things the way I do!
I don't "calibrate" to some BS spatial paradigm that may or may not have any basis in reality. I don't think you have been reading my posts that you quote.
Loyal
Loyal, post: 455608, member: 228 wrote: I have been RTK since the mid-90s, and that's EXACTLY why I do things the way I do!
I don't "calibrate" to some BS spatial paradigm that may or may not have any basis in reality. I don't think you have been reading my posts that you quote.
Loyal
The calculated positions do have a basis in reality, so do the ones you determined a position for with you RTK. Your AutoCAD system does calculate any spatial paradigm whatever that is. Trimble and Javad calibrate using mathematics. And as Albert Einstien said " Mathematics don't lie". I think it was him anyway.
Skeeter1996, post: 455614, member: 9224 wrote: The calculated positions do have a basis in reality, so do the ones you determined a position for with you RTK. Your AutoCAD system does calculate any spatial paradigm whatever that is. Trimble and Javad calibrate using mathematics. And as Albert Einstien said " Mathematics don't lie". I think it was him anyway.
Skeeter,
I apologize for not being very good at explaining a rather simple process, but I don't know any other way to do get my point across.
How about a question for you:
When you put your "measured Bearing and Distance" on your plat, how do you explain what it's based on?
Do you extract the "calibration" parameters including any tilt, rotation, scaling, Datum, Realization, etc.?
How do you define NORTH, or what a FOOT is in your calibration (as opposed to what a Total Station would measure between any two given points on your plat)?
An LDP does all of that!
Loyal
I feel I've begun to chase my tail now, Loyal. I've achieved my objective in surpassing the " Who'd like to go compare a R10 to a Javad" post replies.
I can see you're not going to share any of you system of correlating calculated to found corner positions. Can't say I learned much, but it's kept away from the dreary world of drafting.
Skeeter1996, post: 455617, member: 9224 wrote: I feel I've begun to chase my tail now, Loyal. I've achieved my objective in surpassing the " Who'd like to go compare a R10 to a Javad" post replies.
I can see you're not going to share any of you system of correlating calculated to found corner positions. Can't say I learned much, but it's kept away from the dreary world of drafting.
I'm pretty sure that I covered that several times, but maybe poorly!
Loyal
Where is my popcorn..........
I see Loyal pulling a cart and Skeeter1996 pushing a cart.
Opposite techniques.
A Harris, post: 455623, member: 81 wrote: Where is my popcorn..........
I see Loyal pulling a cart and Skeeter1996 pushing a cart.
Opposite techniques.
Naw, I'm the one pushing (as in Sisyphus).
🙂
Loyal
Loyal, post: 455624, member: 228 wrote: Naw, I'm the one pushing (as in Sisyphus).
🙂
Loyal
Going to keep pushing or let it roll over you?:cool:
A Harris, post: 455623, member: 81 wrote: Where is my popcorn..........
I see Loyal pulling a cart and Skeeter1996 pushing a cart.
Opposite techniques.
I get the impression that they are using only slightly differing techniques, but widely varying terminologies. The software approach is different in that LDP and site calibration have differing interfaces with the humans, but getting them to pretty much the same result in the field. I bet if they got together and worked on a project, their mutual confusion would evaporate.
A big difference may be that the LDP has a known relationship to any other representation you may want, but the calibration doesn't?
Bill93, post: 455667, member: 87 wrote: A big difference may be that the LDP has a known relationship to any other representation you may want, but the calibration doesn't?
A calibration has to create a projection of some kind. Maybe there is another way to create XYZ from LLH, but I'm not aware of it.
This can be done using of course many different types of projections. I don't think too many people using them even have any clue what type it is. It also has to rotate and scale using the base coordinates. Loyal and I are both saying it's always better to know what projection you are using.
In my case I will always use TM to do an LPD cause more programs like it. I will also use NAD83 and the parameters associated with it. I will choose and metadata my scale, origin lat, long. ect.
I spent a lot of time and energy in the early days of GPS calibrating and it didn't take long to realize it was much better, cleaner, less error prone to do my own set-up and control it.
You have this close to perfect GPS system, the math behind placing XYZ on the earth is better if it's known and there is metadata associated with it.
But if some coordinates are what you want to hold, and they aren't working to your system, then calibrate. I don't usually hold coordinates in great esteem. Especially ones I just calculated from a boundary drawing.
Coordinates for an old instrument survey that are tied as control for a project,,,,,,,,,,those may be more important.
"It also has to rotate and scale using the base coordinates" While I agree with most of your comment, the part about scale is simply not correct. The inception of this whole discussion was based on the fact that the OP missed "Locking" the scale factor at 1.000 .
I think the big difference between Loyal's technique and Skeeters is that Loyal attempts to calculate his BEFORE the field work and Skeeter does his on the fly. (that's how I do it too.) By doing a calibration, you are NOT messing with calculated points. They are loaded into the collector and are never changed. Only the measured points are subject to the transformation of the calibration. You can generate your calibration and use it over and over, send the parameters to other collectors, just like a LDP.
It's funny to me that for years I've heard from so many on this board (and others) that people using Calibration techniques simply don't understand what they are doing... AND from these posts it seems as if some of those commenting about it either don't understand it themselves OR have actually been doing the same things but calling it something else ! Fascinating thread.
Loyal, post: 455616, member: 228 wrote: Skeeter,
I apologize for not being very good at explaining a rather simple process, but I don't know any other way to do get my point across.
How about a question for you:
When you put your "measured Bearing and Distance" on your plat, how do you explain what it's based on?
Do you extract the "calibration" parameters including any tilt, rotation, scaling, Datum, Realization, etc.?
How do you define NORTH, or what a FOOT is in your calibration (as opposed to what a Total Station would measure between any two given points on your plat)?
An LDP does all of that!
Loyal
I usually remove the calibration after doing all my field work and only use a one point calibration. I put the Lat Long coordinate on that calibration point and put my canned Basis of Bearing statement regarding the use of an RTK system to derive bearings. Sometimes I use an OPUS Lat Long on the point, but usually it's just an autonomous position generated by the "here" button.
Occasionally I will leave the calibration on and cite that the basis of bearing was from a previous plat between two corners.
I don't hold the calculated coordinates in esteem either. I'm just using them for corner search. My bearings and distances on my Plat are derived from my measurements. While I don't see alot of value in putting record bearings and distances on my Plat the calculated points are based on past records so they are easily taken from the "calculated" layer in my CAD and it saves a little drafting time. The calculated points are all labeled search so they can be turned off easily when drafting the found bearings and distances. That way you don't accidentally snap to the wrong node. They are usually pretty close together.
Andy J, post: 455685, member: 44 wrote: "It also has to rotate and scale using the base coordinates" While I agree with most of your comment, the part about scale is simply not correct. The inception of this whole discussion was based on the fact that the OP missed "Locking" the scale factor at 1.000 .
I think the big difference between Loyal's technique and Skeeters is that Loyal attempts to calculate his BEFORE the field work and Skeeter does his on the fly. (that's how I do it too.) By doing a calibration, you are NOT messing with calculated points. They are loaded into the collector and are never changed. Only the measured points are subject to the transformation of the calibration. You can generate your calibration and use it over and over, send the parameters to other collectors, just like a LDP.
As I said in another comment the scale of 1 will not produce a ground-grid mesh at elevation which I assume Skeeter is at. There needs to be more going on to make that happen (it's possible the program is taking over and doing it), it would be interesting to see what doing that results in for a ground gird inverses at different elevations.
As far as calculating on the fly, I often won't create any coordinates, I would rather find a corner, then navigate from it to the next one. If I can go around a section without any coordinates that's a good thing. Sometimes I want them, sometimes not, depends. Once you have a corner monument and you have the plat you can just navigate from that monument to the next one. I find it cleaner that way. Same with lot surveys. But there are times I want search coordinates, those almost always get deleted. Sometimes they are a pain, you need to delete them in CAD and the GPS file or they keep coming back.