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.
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.
So do we need to start posting more in the "who'd like to compare a R10 to a Javad" to get that thread to surpass this thread?
Scott Ellis, post: 455778, member: 7154 wrote: So do we need to start posting more in the "who'd like to compare a R10 to a Javad" to get that thread to surpass this thread?
Sure, why not?
:fever:
Loyal, post: 455600, member: 228 wrote: 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
Okay Loyal I'm not giving up. You've found your first corner. The bearing and distance to the next corner goes up and over a steep mountain. From plotting your previous survey on your topo map you know there is a road that goes right past your next corner. How do you navigate to that next corner?
Skeeter1996, post: 455817, member: 9224 wrote: Okay Loyal I'm not giving up. You've found your first corner. The bearing and distance to the next corner goes up and over a steep mountain. From plotting your previous survey on your topo map you know there is a road that goes right past your next corner. How do you navigate to that next corner?
Drive to it using my RTK.
😎
Loyal, post: 455579, member: 228 wrote: I use AutoCAD as a graphic database of sorts. Each Survey (usually a Mineral Survey or a particular PLSS "line" [Section Corner to Section Corner]) exists as a BLOCK in the Project .dwg. When I find [say] Corner No.1 of MS-xxxx, I grab that BLOCK and move Corner-1 Theo. over to Corner 1 Found. This moves the entire Survey (w/ Bearing Trees, Objects, Rocks, Shafts, Adits, and terrain calls) over to MY reality. Once I find [say] Corner No.2 of said MS, I'll rotate the entire Block to fit that particular Bearing, and usually move "up to Corner No.2." I DON'T (usually) do any scaling of the Block, but there are exceptions. Once I have found all of the Corners, the BLOCK has served its purpose, and is frozen.
Loyal
Oh my, there is another guy in 2017 that has found a use for a laptop.
