Posted some time back.?ÿ I work in mostly engineering and CNC machining but bought a Geodimeter ATS 4000 robot and matching RMT for some simple stuff years back.?ÿ To be honest, it has been a struggle because I think the Geodimeter 'language' or user interface is rather hard to grasp on the entry side.?ÿ?ÿ
In any case, I am trying to solve a minor issue here.?ÿ Seems this robot does not even have the most simple of programs like COGO.?ÿ I am simply trying to use the gun for simple personal layouts as as-builts for relative info only.?ÿ The way I resort to using it is setting out as a free station in P20.?ÿ Before I do that, I enter the menu and visit the site and area.?ÿ I ALWAYS just make P1 N0.000,E0.000, then P2 usually with N0.000 and E either a predetermined value or "estimated" value.?ÿ This has created some issues and I wonder if what I am doing is making the robot make deviation factors that I don't want.?ÿ?ÿ
For instance.?ÿ I was shoot in rough corners for a new building in which I wanted one corner to be P1 N0/E0, then the next at P2 N0/E100.?ÿ I knew?ÿ my shot was not going to be right on, but wanted the gun to then make the adjustment and tell me the actual distance from P1, then just make target adjustments.?ÿ What I found is that when I returned to P1 to confirm, it read 2ft off!?ÿ There is NO way I was 2ft off.?ÿ?ÿ
Before we get too far, I should say that I have tested this gun as recent as 3 days ago shooting a baseline with good points.?ÿ I used it as a reference and was not on the baseline, but in a triangulated position.?ÿ Distance between points was recorded as 1323.150', I shot it at 1323.160'.?ÿ I have shot others over this sort of swing and distance to prove the gun is accurate and seems to work, but when only shooting 100ft or so, I had a 2ft issue, which probably means I am just running the robot incorrectly.?ÿ?ÿ
Can someone make sense of this??ÿ I recall someone in the past making a couple positioning shots just my creating a couple points with a tape measure, but those were likely within .5".?ÿ when I shot the building corners, I knew I would probably be 1-2ft off, but did NOT figure it would move P1??ÿ Can I change some settings to ensure P1 is GOLD and let the gun tell me what the P2 distance is??ÿ?ÿ
Also, I might like to ask about prism pole height??ÿ What do you guys like??ÿ I have one that runs about 6ft at its lowest height.?ÿ I have trained my help to try to dial that plumb float as close as possible, and I calibrated it, but I find it very hard to get perfect results in the field.?ÿ Do you guys resort to a shorty for accuracy, or a tripod possibly??ÿ I really want one.?ÿ Unfortunately I don't have the full radios between robot and RMT to make this easier.?ÿ I suspect my help can EASILY be off an inch just trying to hold the pole plumb.?ÿ?ÿ
In countless tests in a controlled building, with RMT sitting on the ground, and marked positions, the gun shoots deadly accurate.?ÿ I should mention that some of the work done above was in windy conditions and sighting in my shots at 1300ft told the story.?ÿ Not sure if you guys still get quality shots in wind or not, but it was probably 20mph when shooting, and it was hot outside.?ÿ My level settings on my gun showed slightly off center, but was my understanding that the manual settings are "rough", and the gun would self calibrate and hold??ÿ I do have an Aluminum tripod, which I am now wondering about in the sun??ÿ?ÿ
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Maybe, rather than N0.00 E0.00 for P1 tryN5000.00 E5000.00 ?
EDIT: ?ÿAlso, what do you mean by ??target adjustments? ?
Not sure Im understanding exactly what you are doing, but it sounds like you shouldnt be using free station. First, ditch the aluminum tripod, that instrument is way too heavy and has too much torque to be very accurate on aluminum. For free station to work the 2 points have to be the correct distance apart, matching the inverse between the coordinates. I would create 2 points using whatever coordinates you want in the area file, then go to P20 and use one of them as your setup point and the other as your backsight, using hor angle only, no distance. Then take your shots and rotate and move them to what you want. Been awhile since I used a 4000, and the Geodimeter software is a strange animal to get used to.?ÿ
Most people who used the Geodimeter of that vintage attached seperate data collectors / controllers to operate them. The native controller system baffled just about everyone.?ÿ One guy I worked with understood it and sang it's praises. Only one guy. He showed it to me more than once, trying to win me over. What I remember is that there are a lot of esoteric code entries to be remembered and entered with exact syntax. You know. DOS.?ÿ
It sound like you are free stationing. AKA resecting. A more common tactic is to assume a coordinate for the instrument and a direction for the backsight (which can be achieved by assuming another coordinate for the backsight if you like). Try doing that, then shoot your building corners. Note that most of us will assume a non-zero starting point (such as 5000,5000) to avoid negative coordinates.?ÿ
I'm not clear if your 2 foot problem is caused by an angular error or a distance error. If it's angular you could have a bad tribrach, troubles with the tripod stability, or collimation errors. If its distance, there may be a prism constant issue. It is possible that the EDM will measure long distances accurately but have trouble with shorter ones.?ÿ You have rather long-in-the-tooth electronics there.?ÿ?ÿ
Brad, when I say "target adjustment", I just mean make adjustments with the prism pole to obtain the value that I have entered in the gun.?ÿ?ÿ
Brad/Eddy
Here is a basic idea of how I try to use the gun.?ÿ I need to shoot the corners of a new, non-existing building.?ÿ I know that the length of the building needs to be 100ft, and the gun is the best tool to get that accurate measurement.?ÿ I setup as a free station at a 3rd position, set P1 N0/E0, then P2 N0/E100, and go "about 100ft" in the direction I want the point.?ÿ I would usually use a roll tape or something to get close, but knowing I will accept what the gun shoots because it is way more accurate.?ÿ?ÿ
I 'could' setup on the baseline first and shoot the distance and set those points I guess.?ÿ?ÿ
Also, I did read in the book and maybe I am not paying attention but when shooting the P2, it should be displaying the actual 'difference' between the shot and entered value in the area file for HD and HA.?ÿ If that is the case, I really should be able to just make adjustments until the 'difference' is eliminated??ÿ?ÿ
Do you guys get much error from how the prism pole is held, PPM, etc??ÿ I realize I am shooting 1300+ft so maybe I need to make some adjustments to my routine and calibrations.?ÿ?ÿ
Do you guys get much error from how the prism pole is held, PPM, etc??ÿ I realize I am shooting 1300+ft so maybe I need to make some adjustments to my routine and calibrations.?ÿ?ÿ
Pole plumbing, prism constant, and PPM are all much less than 2 ft.?ÿ If you are shooting 1300 ft more or less perpendicular to the line you want to measure, then tripod and tribrach problems will be magnified.?ÿ Can't you set up closer?
In the case of the 1300ft shot, what I am puzzled about is I set 2 flags on the 'established baseline' years ago with this gun, then set two posts in the ground on my property.?ÿ When I shot that line again the other day, I shot it within .01' of the survey, but I did not expect for my posts and flags to be like 7-8" off!?ÿ I now have to go setup directly on that baseline to determine the issue and set new points.?ÿ By being right on the baseline, that will basically remove any error.?ÿ It will also let me get the real distance so I can ensure everything is checked and good.?ÿ?ÿ
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In the case where I was 2ft off, I was actually only 100ft from the baseline!?ÿ I was actually setup INSIDE the building area.?ÿ I realize in this instance, only gross error would cause this.?ÿ?ÿ
I dont remember if there is an option in that gun to read just a horizontal angle for a backsight, you may have to have a point stored. It sounds like you are just assuming coordinates for everything anyway, so I would set the instrument up at P1, 0,0, and before you start Program 20 go set your prism on a point on the building line, it doesnt matter the distance as long as its on the line you want. Shoot the horizontal distance to it, then enter that in the area file as your easting coordinate for P3. Then start Program 20, backsight P3, then you can use Program 23 to stake P2, which would be 0,100.?ÿ
If you have Program 24 and the building has all square corners, you can stake the whole building by just using Stations along and offsets from your line between P1 and P2.?ÿ
program 24 is what you want, cogo program 60? 63? was an add on
Geodimeter has COGO functions for nearly everything you could want....?ÿ if they are loaded on your collector.?ÿ I LOVED the Geodimeter software, and still miss old #49, now back in the hands of "eddycreek".?ÿ?ÿ
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since I can't seem to be able to edit... I don't know about the 400 series software, I used a 650 Bergstrand edition that came with every program available. I probably didn't use half of what was in there.
Andy, I recall chatting with you on COGO, and it sounds like what I really need, but it is just not loaded on this gun and probably not worth the investment.?ÿ I didn't even pay to ship the unit to a service center to replace the batteries.?ÿ We ended up changing them in house and just have to live with the "low battery" warning everytime it fires up.?ÿ?ÿ
Due to the wind and now rain, I have not been able to get too much testing done, but I did go setup on that 1300ft baseline and used a tripod on the prism pole and got things right down to a nat's ass.?ÿ The survey has the shot at 1323.150 and I shot 1323.210, however, there is an obvious issue with one pin that was likely bumped with a lawn mower.?ÿ Once I straighten it, it should be nearly exact.?ÿ?ÿ
I just used HD as my distance, with no further establishment other than ensuring the gun was well leveled and over the second pin.?ÿ I played with the PPM values by changing the temp and pressure and could get about .10' difference but when using the appropriate values, I shot it pretty close.?ÿ?ÿ
I suspect I need to better understand deviation and scale factors.?ÿ?ÿ
I also would like to better understand the leveling!?ÿ I can tell you that I level the unit, then check in the level display, in which I always have the bars dead center.?ÿ Then I hit A/M so the gun will calibrate itself in "fine mode".?ÿ I then observe the bars moving off center slightly and will move around a bit.?ÿ I am not sure if this is normal??ÿ?ÿ
Also, to obtain my shots, I pretty much always use "autolock" for the RMT.?ÿ Before taking a shot, I will ensure a (+) is displayed and verify that the sighting looks correct.?ÿ?ÿ
Here is where I am guys.?ÿ I FINALLY got reasonable outdoor conditions, no wind, and using a tripod on my prism pole so I can hammer down some accuracy.?ÿ?ÿ
What I first did was visit two points on a baseline for this building that I previously set with the gun.?ÿ I was in a triangulated free station position and used the values that it should be, which is P1 0,0, P2 0,102.000.?ÿ I shot that within .01' after establishing with P20
I then decided to purposely fudge the data to see what would happen.?ÿ I changed P2 to 0,103.000 and ran back through P20.?ÿ This seems to be creating deviation factors that I cannot understand, nor adjust either before the second point is saved or after.?ÿ I tried everything.?ÿ After recording the second point, I get a points listing clearly showing an Eastings correction of .48', deviation factors, etc.?ÿ I even tried to alter the point in the table afterwords and tried to turn off the RT/RAD offsets for the second point, hoping it would just honor the first point only.?ÿ No joy.?ÿ?ÿ
After shooting in P2 in P20 setup, I shot it again, and it spit out like 102.530', I then returned to P1 and it was about .5' off as well, so the gun is 'factoring' when I don't want it to, or at least want the ability to make adjustments!?ÿ?ÿ
I then setup on the baseline on one point and the HD was 102.050'.?ÿ These are NOT monuments, just flags for base rock perimeter for now.?ÿ However, it proves the gun can do it, and I really doubt there are big issues with the gun.?ÿ?ÿ
As a last ditch, I tried to just long hand it and used F21 to zero the HA so I could gather the HA and HD between two points, and their angle.?ÿ When I calculated that, I was 1-2" off in length!?ÿ That is not acceptable so apparently long hand is not going to get me there, even when carrying 4 decimals.?ÿ Odd....
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Basically the issue is that I am using P20 to establish as a free station, but I better be dead on or bad things happen and the gun will lie to me.?ÿ I do NOT have P24 so any other ideas to simply get an ACCURATE measurement between two points so I can use them for establishment would be great!?ÿ?ÿ
I am officially a moron!?ÿ I always forget that gun, because there is only one decimal, is in deg/min/sec.?ÿ After doing the conversions, when I shot that baseline above while on the line, I shot 102.050'.?ÿ When I setup in a triangulated position and just long hand the math and just use the angle and HD, I got 102.041' and a separate setup at 102.049'.....!!!!!
That at least makes me feel immensely better that all the math is checking out!?ÿ The gun seems to be rather repeatable.?ÿ?ÿ
Now, if I can just find a way to get the gun to do the math for me between a couple points......
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In the previous post, I found that the gun told me there was an Easting error of .480' for both P1 and P2.?ÿ I entered 103.000 when the actual shot on the line was about 102.050.?ÿ So if I were to deduct those values from 103.000, that is 102.040' which is well within my margin of error, as I was not trying to get this down to microns, just prove my theories.?ÿ?ÿ
If you are telling the instrument that the distance is 103' when it physically is 102', the free station least squares adjustment it performs will split the difference, hence the 0.48' adjustment. (If I'm understanding what you did.)
Yes sir, that is what I did and concluded.?ÿ It will adjust equally to both ends of that baseline.?ÿ I would assume if I actually had a data collector, I could just go shoot two points and it would easily determine the distance, which could then be entered in the tables for proper establishment.?ÿ Without that, it seems like running an initial long hand calc is what has to happen.?ÿ Either that or I have to run through P20, then apply the deviation factor and make adjustments in the table and shoot again.?ÿ Right now I am looking for a quick phone app that I can use to run the numbers for me.?ÿ?ÿ
Just hard to justify buying additional equipment for no more than I use the instrument.?ÿ?ÿ
Any ideas on such an app that might help me along? I don't think getting connected to the instrument will be realistic due to the vintage, and I think my only other option would be finding an old Geodimeter collector??ÿ The instrument does have a built in radio on it, but I do not have an RPU and such for the prism pole.?ÿ?ÿ
I think you're overthinking this. (If I'm understanding what your goal is)
Set instrument on point A. Sight the line you want to establish to point B. measure that random distance.
If Point A is (0,0) then Point B is (0, "measured distance" ) or ("measured distance, 0)
P20 to establish the station. residuals should only be the slight difference from first measurement of B to second.
Stake out the line A-B at the desired final distance, C
Stake out the rest of the positions in relation to line A-C.
