Rookie questions on total station setup. Geodimeter 4400/ATS
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 [email][email protected][/email] and I’ll put some more detailed notes together for you.
Bob, Just wondering how you’re coming along with the project! Andy
Thanks for asking. With Chris’s help, I determined I was doing a few things wrong. I was not going through the P20 set out procedure correctly, did not understand the job and area file setups, and in general I thought the coordinates that were going to be kicked out would be polar and I would have to convert them to cartesian. I was finally able to setup on a baseline, orient my first point as N0E0 to set my origin there, and everything fell into place. I realize that is probably not how surveyors might do it, but since I am use to CNC stuff, I like to know where my XY0 is.
I do have a couple quick questions you can probably answer.
1. The RMT is the only target I have and realize the scope hairs aim at the arrows while the gun on top seems to zero in on the prism. How would this work with a basic passive prism since it seems I cannot manually target the center of the prism? Do I need a special target?
2. How is angularity handled with the scope relative to the target? I see angle mounts for targets and though most of my work would have the target within a couple feet in elevation relative to the scope center, I have to wonder if I was shooting something, say the bottom of a pond, how would I ensure the center and distance is correct relative to the center of the rod?
bob james, post: 393843, member: 12050 wrote: Thanks for asking. With Chris’s help, I determined I was doing a few things wrong. I was not going through the P20 set out procedure correctly, did not understand the job and area file setups, and in general I thought the coordinates that were going to be kicked out would be polar and I would have to convert them to cartesian. I was finally able to setup on a baseline, orient my first point as N0E0 to set my origin there, and everything fell into place. I realize that is probably not how surveyors might do it, but since I am use to CNC stuff, I like to know where my XY0 is.
that’s great! I have to admit, even though it’s only been about a year or so since I used my CU on a daily basis, I couldn’t remember all the step by steps so I didn’t want to send you bad info.
I do have a couple quick questions you can probably answer.
1. The RMT is the only target I have and realize the scope hairs aim at the arrows while the gun on top seems to zero in on the prism. How would this work with a basic passive prism since it seems I cannot manually target the center of the prism? Do I need a special target?
If I’m understanding your question, with a passive target you would sight the crosshairs to the center of the target, as with any other gun. The offset you are seeing is a product of the interaction with the RMT and the instrument.
2. How is angularity handled with the scope relative to the target? I see angle mounts for targets and though most of my work would have the target within a couple feet in elevation relative to the scope center, I have to wonder if I was shooting something, say the bottom of a pond, how would I ensure the center and distance is correct relative to the center of the rod?
That is a weak point of the RMT, for sure. There was a mount made that angled itself based on the position of the vertical axis of the gun. (part Number 571 204 240) I believe it somehow pinged the gun for that data and adjusted itself to mirror. But then 360 degree prisms came on the scene and made that bulky mount obsolete.
Trying to post a pic
Not sure if you have it but program 24 sounds like what you are looking for. Ref. line, setup where you can see two points locate them then by using them as your baseline stake any kind of o/s
James, I don’t have P24 but not sure how it might work different than setting up with P20 as a free station and locating the ends up the line in that? Seems work great great for what I need anyway. Maybe that program sort of sidesteps the length of the line issue and just sets one bearing at 0 assuming it is a line and uses the station data to calculate the length?
bob james, post: 393908, member: 12050 wrote: James, I don’t have P24 but not sure how it might work different than setting up with P20 as a free station and locating the ends up the line in that? Seems work great great for what I need anyway. Maybe that program sort of sidesteps the length of the line issue and just sets one bearing at 0 assuming it is a line and uses the station data to calculate the length?
P24 will give you a current readout of your prism location in relation to the specified line, defined by any two points in your collector. As you move, it will guide you to staking anywhere on that line or on any needed offset.
It’s totally different than P20, which is just how you get the instrument oriented on the site.hmm, that is confusing because that I what I am doing now with P20. I setup as a free station and set two points in my area file. One is N0E0, the next is say N0E200. After I complete P20 setup and shoot those points, I can walk anywhere along that line and will see an N0 as my northing is oriented along that line.
bob james, post: 393987, member: 12050 wrote: hmm, that is confusing because that I what I am doing now with P20. I setup as a free station and set two points in my area file. One is N0E0, the next is say N0E200. After I complete P20 setup and shoot those points, I can walk anywhere along that line and will see an N0 as my northing is oriented along that line.
When you say “free station” are you setting up on one end of the line you are staking out? Or setting up on a random spot, then sighting two points (A and B)? . Imagine A and B two random pairs of complex coordinates (ie NOT a cardinal direction line) and staking the line between them.. Then the readout wouldn’t be as easy as walking until your northing reads Zero. P24 allows you to define that line as any two points in the file.
I’m trying to remember what exactly your task is, but I recall it was very specific. So maybe that work around of just using P20 will suffice. But in the surveying world, that would be a surefire way to screw up a project from the start.
So you are saying, if I understand correctly, with P24, you can just elect any two points that are in your job file that you have shot, and align to those?
I will indicate my procedure just so we are clear. Chose any random station site between two points. Assign the two points in the area file with N0E0, and N0E200, go through P20 and shoot in those two points for your free station. If you walk anywhere on that line, the machine will return N0 as the Northing has been aligned with that stake line between the two points.
bob james, post: 394009, member: 12050 wrote: So you are saying, if I understand correctly, with P24, you can just elect any two points that are in your job file that you have shot, and align to those?
I will indicate my procedure just so we are clear. Chose any random station site between two points. Assign the two points in the area file with N0E0, and N0E200, go through P20 and shoot in those two points for your free station. If you walk anywhere on that line, the machine will return N0 as the Northing has been aligned with that stake line between the two points.
You will have to put the points in an area file to use them.
When you do what you are saying, I assume you have actually set the 2 points exactly 200′ apart. Then you can free station from anywhere (set up the instrument anywhere in the vicinity), shoot the 2 points, and the instrument determines the coordinates of the instrument. You can store that position or not. I always kept a file I called Area51 to stick those points in. Unless you actrually set something there to come back to, it’s only necessary if you for some reason lose your location and have to set up again (i.e. some glitch shuts the instrument down) If the instrument hasn’t been moved, you can just tell it you are setting on that point you stored in Area 51 and backsight one of the other points and take off.
If you have a file with a bunch of building corners stored in it, and wanted to set some offsets off one of the lines, you can pick the points on the 2 corners, and the instrument will tell you where you are in relation to them, both along the line a perpendicular to the line. Then you can pick 2 other points and offset from them. Laid out a bunch of buildings that way.
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