Bob,
Switch on, get it ready to measure, take reading without selecting a programme - ie in P0
Display will show HA, VA, SD
press ENT
Display will show HA, HD, VD
press ENT
display will show N, E, ELE, which is broadly what you want.
If you do MENU 3 1 and then put in the station coordinates it will now use those when calculating the point position.
If you have set a true bearing using F21 it will now give you the grid coordinates on future observations.
As I suggested earlier, if you set on your known baseline and sight along it that will enable you to set the initial bearing angle.
The swimming pool was just an example of the type of situation when you might be measuring a point which was offset to the side of the block target. (The distance is taken to the centre of the target, but the optical pointing is to the front face, hence isn't quite the same position when projected through to the centre. One could angle the block to be square to the instrument but then the offset will change from 35mm. to 35mm+ a bit, since the target edge is square and 20mm wide).
Jim,
Be careful if you ever do one when it's full - the underwater bits are quite tricky! and its best not to set in the pool in that circumstance.
Got it! Or I think. My mistake was not understanding the N/E/ELE. I used the F21 to set my Easting to 0 and was able to verify the distance between two points as correct.
So the Northing ends up being the horizontal distance? Easting is calculated internally based on the HA and distance shot to give the distance between points? I set my instrument height in menu 31 and that came in correct as well.
So it seems what I would need to do here without COGO is determine a bunch of hypotenuse lengths as my target Northings? If I setup on a known property corner pin, shoot the next corner pin and reference that as my Easting zero, I have defined that line and all other shots should be relative to that setup?
Is there not an easier way to set relative points without the need for hand calculation?
So you don't have any of the COGO programs ?? I used only the CU with the old school programs for many years without much trouble. It's not as user friendly as a modern "windows" style system, but once you get the programs down, (and it's only like 4-5 that you would use every day) it's bulletproof.
Does not appear so. When I push/hold the PRG button for the list of loaded programs, program 61 I believe is COGO and it is in brackets indicating is was not loaded up. I also tried hitting PRG=61/ENT and it errors out. I don't see how they were using the gun without this. Would sort of seem common place for the need to calculate lines and such. Maybe they were using a data collector to run the numbers for them? At this point, it would be nice to find at least a basic phone app to just do the basic math for me. For instance, I will need to set an alternate setup point to be more conveniently located for all shots, but then I need to back calculate everything.
OK, I am not sure I am fully grasping the concept here. I think I have the northing right as the distance to the shot? That should be a very straight forward value. Easting is what I am confused about. I think this is the calculated distance as a straight line between the easting line reference and any other point? This would always be a right angle to the easting reference? Is there a way to set the northing reference to 0 at a point so I can measure the distance between points?
I guess when I think about this, if easting is the distance back to the ref line at 90* angle, if I setup on one corner pin, shoot the next corner and define that as my ref line, technically as I step away from the ref line, the actual distance from that line should always be the easting value?
However, I am thinking about how I might setup at some random point triangulated between the two corner pins. The northing or distance shots and the angle would allow me to determine my position relative to those pins with no problem. However, I then need to calculate the distance between the pins or the leg length based on the angles and distance to each pin from the station?
Maybe I am thinking about this wrong in following along the line between pins, when actually I must draft that differently as a straight line distance from the ref line to any point along the line?
I decided to make a quick drawing to show my examples. Please critique as needed.
I'm confused by your notations.
You need to think of this as Cartesian coordinates, a Northing and Easting "Pair" define one location.
In your graphic, say you set up on Stn. 1 and measure to Point 2, and assign it coordinates of North 100, East 100. If the distance from 2 to 5 is 500 feet, the coordinates of Point 5 is North 100, East 600. (assuming 2-5 is East) If your CU had the Geodimeter programs, you would just run the "stake to a line" Program (P23? I think) , enter the begin and end points and it would tell you instantly as you move how far along and offset the line you are.
You would need to move your prism and check the position until your NORTHING coordinate is 100.00. The easting coordinate wouldn't matter since you are staking random locations along the line from 2 to 5.
(I'm ignoring your two distances as without the interior angle, they don't mean anything)
(rectangular/polar conversions on a calculator)
The angle between the two distance shots was not added just because I did not take the time to add it, but obviously the station would know that angle.
From the sound of it, I might not have a full understanding of the way the station runs. I figured Northing was simply a horizontal distance shot but from the above explanation, that would not compute since the Northing value would be ever changing along a line. As you could imagine, as the prism approaches a right angle between the line and the station location, that distance would be the shortest, and as you move away from the station, but stay on the line, the Northing value would increase?
I may need to scrub my understanding and refresh....
To set a point, you need a baseline. A baseline consists of the coordinates of two known points. They can be tied to real world (or State plane) coordinates, or they can be arbitrary, ssay set one at 0,0 (x,y) and the other as whatever distance (d) it is away as your north, so it would be (d,0). From that baseline you can stake out your other points. That's using Cartesian coordinates. You can also stake those points out radially, i.e. an angle from say N (if that's how you set your baseline) and a distance.
Ah, that might be making more sense to me now. I will make another drawing to verify things but I work in terms of XYZ all day long. I will need to get more experienced using northing/easting but it should not much matter for now.
If this is truly a cartesian system, my life should be much easier, and I can see why you would need to define at least 2 points so you can generate a reference baseline to work from. However, you need a datum point or center. I don't always want the station to be the center. Basically if I step over to my CNC stuff, I would want to define two points so I have a true X or Y plane, then define one end of that line as XY0. All other dims work from that zero?
Now if this works as a grid, I can see why Andy said the northing would not change along a line. The station is doing the number crunching with the angle and distance shots to keep it relative to the datum baseline? So you can be anywhere on that baseline and if I set that to 0 when I setup up, all my shots on that line should be 0 northing?
In my previous PDF, I might reference that as an example for now. so when I shoot from STN PT1, I would need to probably select P20 program to set out as a free station? I would shoot PT2 and PT5 as the two known points? I assume there is some function to apply this line as the datum line? How about assigning PT2 as my datum point? Once that is complete, if PT3 is on the line and say 300ft from PT2, that would be an easting of 300 and northing of 0?
if PT4 is also 300ft from PT2 but offset up 50ft, that would be easting of 300 and northing of -50, depending on how the grid it defined as pos/neg?
yes, you are getting the basics... In my simplified example, the Northing would remain the same, but of course in the real world it would change as you move along the line. For the example though, it's easier to explain if the line you are staking out is due East. Do you have P24 in your CU? I'm pretty sure that is "stake a line"
Cartesian coordinates are EXACTLY what we use every day. And the conversion from Polar to Rectangular is how we convert all those angle/distance measurements into the Northing/Easting pairs that define what we are mapping or staking out. We can also introduce the Z to that when doing our topographic maps, by measuring and recording the height of the instrument and the prism.
Here is a really poor pic of the programs loaded. I put a small tic next to each. It seems there are really no real total station programs, leaving me to wonder how in the world it was ever used. I guess that might be why the station and target appear to be brand spankin new. Like not even any scratches on the base.
well, you'd have to know how it was being used.. it's a fairly old instrument. Maybe it was just used to collect data and process in the office later. Are there any UDS's set up?
I spent some time trying to setup as a free station with two points. I was unable to get there. Somehow I was able to get through the P20 setup but the books really don't walk through creating a new job and area, etc. I was able to find the edit functions through the menu to change things in these files but one would think there would be a "make new file" button....
I just shot a point, wrote down the NE data, then I think I used the edit functions to add the coordinates to the pt I created in the area file so when I plugged through the P20 program, it found and used those. However, I figured there would be a way to shoot a pt, then use those in setup, but seems it wants pre-entered coordinates?
So without all these other programs, is there any way to define a line based on two points? I want to shoot a pt, call it zero, then shoot another point to define a line and grid based on those two points. Without defining two points, I am not sure how I would get a relative grid to what I need?
I checked the UDS programs and there is only one, TOPO. Plugging through it, it seems like it is setup to bypass most startup functions and just focus on plugging points. It goes right to adding points. Due to the ATS model and RMT target, that seems inline that it was doing only TOPO work.
Am I basically going to need to figure out how to create a custom UDS to get around the lack of software?
Bob,
This could get quite complicated - e-mail me at cjmills@freeuk.com and I'll put some more detailed notes together for you.
