Situation: Star*net adjusted control network, done using grid (VT83 Coordinate System).
Now I'm going back out into the field to do some re-measuring, staking out or whatever.
Would I have Star*net output a "Ground Coordinate" file, and put those into the DC?
I don't have *net. But, keep asking "dumb" questions. WAY better than making "Dumb" mistakes. I'm encouraging you. Glad to see you doing this.
I suspect that what ever units you put into *net, is what you get back...unless it has a grid to ground method, which would mean it has geoid file in it, and a way to manually address the Scale factors.... Keep asking.
Nate
rfc, post: 386749, member: 8882 wrote: Situation: Star*net adjusted control network, done using grid (VT83 Coordinate System).
Now I'm going back out into the field to do some re-measuring, staking out or whatever.
Would I have Star*net output a "Ground Coordinate" file, and put those into the DC?
RFC, Survce is what I recall u using. You can do either just set up Survce to match.
You should be able to set your data collector to the "VT83" coordinate system. System will then scale measurements accordingly to keep you on the grid.
RFC,
From what I understand you are using only a total station with an EDM. So your distances originated as ground distances. So if StarNet converted your distances from ground to grid, then you need to find the averaged combined scale factor for your project. Then apply this scale factor into your data collector. This way the coordinates will be grid, while the distances from your EDM will be reduced from ground to grid by the DC. All the raw data will be in ground distances. Just be certain to apply the scale factor the correct way. Often the ground distances are larger than ground distances, but NOT always. Scale factor can reverse this depending where you are in reference to the central meridian, and your elevation.
leegreen, post: 386833, member: 2332 wrote: RFC,
From what I understand you are using only a total station with an EDM. So your distances originated as ground distances. So if StarNet converted your distances from ground to grid, then you need to find the averaged combined scale factor for your project. Then apply this scale factor into your data collector. This way the coordinates will be grid, while the distances from your EDM will be reduced from ground to grid by the DC. All the raw data will be in ground distances. Just be certain to apply the scale factor the correct way. Often the ground distances are larger than ground distances, but NOT always. Scale factor can reverse this depending where you are in reference to the central meridian, and your elevation.
Thank you, Lee.
Starnet did convert them to grid, but among the choices in the Project Options, Other files, it can output a "Ground Coordinate File". I think what I'm getting is that (as Adam says), it doesn't matter as long as they both match. I trust Starnet at the moment more than I trust all my settings in SurvCE. But, if I understand you correctly, it might make sense to do everything in the field (i.e. SurvCE) on the ground; that is, output the csv file, bring it into SurvCE and carry on.
rfc, post: 386845, member: 8882 wrote: Thank you, Lee.
Starnet did convert them to grid, but among the choices in the Project Options, Other files, it can output a "Ground Coordinate File". I think what I'm getting is that (as Adam says), it doesn't matter as long as they both match. I trust Starnet at the moment more than I trust all my settings in SurvCE. But, if I understand you correctly, it might make sense to do everything in the field (i.e. SurvCE) on the ground; that is, output the csv file, bring it into SurvCE and carry on.
That's correct. You should do everything on ground distance and ground coordinates. In fact I suggest you move all your points to an assumed coordinate system such as 10000N, 15000E. This way you and others will know it is NOT on Grid VT State Plane coordinates. Since you do not use GPS, then no need for you to use grid coordinates. Grid is used by DOT with large road projects, and is a nightmare to work with on boundary work, especially for those who don't understand it.
rfc, post: 386845, member: 8882 wrote: Thank you, Lee.
Starnet did convert them to grid, but among the choices in the Project Options, Other files, it can output a "Ground Coordinate File". I think what I'm getting is that (as Adam says), it doesn't matter as long as they both match. I trust Starnet at the moment more than I trust all my settings in SurvCE. But, if I understand you correctly, it might make sense to do everything in the field (i.e. SurvCE) on the ground; that is, output the csv file, bring it into SurvCE and carry on.
Once you set the projection in Equipment/Localizion/system. Then tap TS and tap Auto scale to grid. This will compute grid coordinates in the collector. A side note SurvCE Raw data will be stored ground distances no matter what projection or scaling you use.
Mark Mayer, post: 386831, member: 424 wrote: You should be able to set your data collector to the "VT83" coordinate system. System will then scale measurements accordingly to keep you on the grid.
I'm pretty sure SurvCe won't apply the scale until you tell it a factor or tell it to auto scale to grid in the settings even when a coordinate system is selected.
leegreen, post: 386833, member: 2332 wrote: RFC,
From what I understand you are using only a total station with an EDM. So your distances originated as ground distances. So if StarNet converted your distances from ground to grid, then you need to find the averaged combined scale factor for your project. Then apply this scale factor into your data collector. This way the coordinates will be grid, while the distances from your EDM will be reduced from ground to grid by the DC. All the raw data will be in ground distances. Just be certain to apply the scale factor the correct way. Often the ground distances are larger than ground distances, but NOT always. Scale factor can reverse this depending where you are in reference to the central meridian, and your elevation.
Still struggling with this. An inverse between two adjusted points in Starnet results in different data than the same inverse on the DC. I'm pretty sure the Average combined scale factor in the DC is still set to 1.00000. Would the Average Combined Scale factor be .99996428571429? Here's the screen from Starnet:
rfc, post: 386749, member: 8882 wrote: Situation: Star*net adjusted control network, done using grid (VT83 Coordinate System).
Now I'm going back out into the field to do some re-measuring, staking out or whatever.
Would I have Star*net output a "Ground Coordinate" file, and put those into the DC?
No!!!!! If you want to output surface distances, do that at the convenience of your desktop. Do NOT molest your coordinates. Run uncorrected in the field if you like, then correct the raw data at the office and evaluate. There are no such things as ground coordinates. This will be bad ju-ju. Get on the grid, and stay on the grid. If you don't like the scales, build a LDP so you can work it. Otherwise, don't mix and match these. It will bite you in the butt eventually.
Adam, post: 386854, member: 8900 wrote: I'm pretty sure SurvCe won't apply the scale until you tell it a factor or tell it to auto scale to grid in the settings even when a coordinate system is selected.
Kris Morgan, post: 387845, member: 29 wrote: No!!!!! If you want to output surface distances, do that at the convenience of your desktop. Do NOT molest your coordinates. Run uncorrected in the field if you like, then correct the raw data at the office and evaluate. There are no such things as ground coordinates. This will be bad ju-ju. Get on the grid, and stay on the grid. If you don't like the scales, build a LDP so you can work it. Otherwise, don't mix and match these. It will bite you in the butt eventually.
I've put the adjusted coordinates back into the DC. I investigated Adam's comment about getting SurvCE on the same page, and it's still not adding up.
Heres the screen you get when you "Edit System":
The Scale factor matches that found in Star*net (as one might expect for VT83).
But in the Localization Screen that Adam points to, it shows:
I haven't changed this...ever. So, if everything is set up properly, why would an inverse in Starnet between two points be different than the inverse between the same two points in SurvCE?
With the scale at one you should get ground distances when you inverse between two points shot with those settings. That is if your total station isn't applying any scaling. To get grid distances you need to type in the .99996429 into the scale on the TS screen. You have an older version so it won't auto scale. The points that are imported are whatever they are when you import them unless you go in and scale them under cogo.
Adam, post: 387853, member: 8900 wrote: With the scale at one you should get ground distances when you inverse between two points shot with those settings. That is if your total station isn't applying any scaling. To get grid distances you need to type in the .99996429 into the scale on the TS screen. You have an older version so it won't auto scale. The points that are imported are whatever they are when you import them unless you go in and scale them under cogo.
No scaling has taken place in the TS. Nor, apparently in the DC. So, if one is moving back and forth from SurvCE to Star*net, and Star*net is set to VT83, should that scale have been set prior to making any observations?
As all of my observations so far have been taken without setting the scale, am I hosed?
Put another way, if Starnet is set to grid (VT83), are all the observations expected to be previously set to grid in the DC prior to exporting?
I'm not familiar with starnet, RFC. Survce, writes the distances as what is read from the totalstation which is usually ground. I use Carlson Survnet in the office and when you set the projection to a state plane system, the ground distances from the raw data are converted to grid distances. You have to be careful in Carlson about knowing what a coordinate is or you could get mixed up and double dip on the scaling. If the coordinates from the Starnet are true state plane coordinates you will need to set the scale in TS on SurvCe to compute state plane coordinates. Still if you do this, Survce is recording the ground distances in the raw file and then scaling to compute coordinates.
By the way, I am just a user of Carlson Survey and Survce so take my advice with a grain o salt.;)
Kris Morgan, post: 387845, member: 29 wrote: No!!!!! If you want to output surface distances, do that at the convenience of your desktop. Do NOT molest your coordinates. Run uncorrected in the field if you like, then correct the raw data at the office and evaluate. There are no such things as ground coordinates. This will be bad ju-ju. Get on the grid, and stay on the grid. If you don't like the scales, build a LDP so you can work it. Otherwise, don't mix and match these. It will bite you in the butt eventually.
"There are no such things as ground coordinates. "
Really? I've been using then every day for over 40 years!
Adam is incorrect.
If you have grid coordinates, then with a scale factor of 1.0000 you get grid distances. You apply the combined scale factor to a distance, not to coordinates.
But if you take the project off grid, back to assumed coordinates, then use 1.0000 scale factor and all the distances will be referenced to ground. Most boundary surveys are performed at an assumed coordinate system with no scale factor, using only ground distances.
I inverse between two points in Star*net. HD shows 1689.2966. Brought the adjusted coordinate file into SurvCE (NOT the "Ground coordinate file".)
Then did an inverse between the same two points. Here's what I got:
Let's try to simplify the questions:
When SurvCE writes an .rw5, does it ALWAYS output ground distances, regardless of settings within the DC?
When Star Carlson/Star*net takes that .rw5 in, and you set the Project to use Grid (VT83 or whatever), does it:
a) Expect Grid coordinates?,
b) Expect Ground coordinates?, and, if the latter,
Does it convert them during the adjustment?
The data you have shown from SurvCE is what what I expected. The "HDist" is your Grid distance, while the "Ground HDist" is what you'd get with the EDM. Most often the ground will be larger than the grid distances in your area do to elevation and location from the central merdian.
YES - When SurvCE writes an .rw5, it ALWAYS output ground distances, regardless of settings within the DC.
Answer is A - When Star Carlson/Star*net takes that .rw5 in, and you set the Project to use Grid (VT83 or whatever), does it:
a) Expect Grid coordinates?,
b) Expect Ground coordinates?, and, if the latter,
Does it convert them during the adjustment?
