For those that use SPC, would you mind flowcharting it for me?

Nate, I use survey pro 5.1. My Ranger and software work in spcs and I can also specify a "mapping plane ground."
I pick a point, assign coordinates 10,000, 10,000, ground elevation, and CF at that point. Survey pro recalculates the survey using local coordinates, ground distance, and then I output to the computer.

In CAD, I use the angle between grid and geodetic to rotate all coordinates about my scaling point. My theory is that since the old timer USPLSS surveyors used ground distance and magnetic north declinated to true north, that I should do the same. Geodetic north is almost and close enough to a true meridian in Northeast Mississippi to call it good. I plot my deeds, work on calcs, rotate back to grid north, and upload my new local coordinates to my point file in survey pro. I can choose to stay in local coordinates or switch back to state plane in the field. My total station uses the GPS point data to generate a local scale factor and store the point as a spc coordinate.

My survey plats and data contain geodetic north and ground distance along with a local coordinate system. My survey pro file contains SPC. I do things the hard way, and maybe not the best way. I know my software will annotate a line with either or both local and grid values given the SPC coordinate system. I just have to slow down enough to learn my software!

I hope this helps somewhat with my current way of doing things. I am looking to improve. I am not familiar with Carlson.

I work in grid only. I have found no reason to switch between ground coordinates and SPC. I use survey pro for field work and Carlson for drafting.

When starting a job, I either find a known control point (like A.H.T.D. GPS control point) or I start with a approximate SPC coordinate then collect GPS data to do a OPUS solution later then just translate my points.

I never have to mess with a scale factor in the field because my data collector does everything for me. If I need to stake a point out with a ground distances, in survey pro you simply put in the ground distance and then just hit a button to apply your scale factor.

When you start drafting you will need to come up with a scale factor to input for Carlson to annotate the ground distances. I like to come up with an average scale factor for the project and if you do it right it should match your data collector ground distances.

On the drawing I get pretty detailed in showing the metadata. I usually annotate two PLSS corners with SPC and one with LAT and LONG and a convergence angle. In the basis of bearing I will show a scale factor to get the ground distances back to grid.

The great thing about SPC is you can load your data collector with the job and setup on a know point and your ready to go. No localizations just check into a point and you should be flat and start collecting data again.

I've never used the software you are asking about.

SPC is a projection of Lat and Long (really ECEF). Good GPS coordinates can be projected into any system including SPC's. You should be able to keep (store) you base data in true GPS coordinates. From there is just projecting them for SPC or a LDP or you own localize ‰ÛÏLDP.‰Û Software that won't do this is not worth owning. I suspect your software is capable, there is no way that your new JAVAD stuff doesn't have these capabilities.

Keep your GPS data true by always adjusting your vectors back to a good point such as a properly derived OPUS point. From there you can easily project into an SPC (if you want something as far off ground as that) or you can use an LDP and almost be right on ground.

I've always used Trimble. In TBC with my GPS data I can go through a dozen projection easily in a half hour (always in the same file) and go back in a snap. I could even project my Utah stuff in an Arkansas SPC.

I'll add.

I'd expect that a way to solve your problem is with the JAVAD data. Just create the projection (LDP) you want for your ground data inside your JAVAD package. Change the projection in the JAVAD data to that. With that done just export the coordinates to your CAD or whatever. It won't require any scale factor or further adjustment from there. On your final file (plat) it would be good to give the meta data (your ground projection stuff) so that someone could later use your projection, which would allow them to back it out to the original (or very near) original GPS coordinates and then project as they see fit.

I'd expect this is all way easier than you think. You just need to escape from the previous mindset (combined scale factoring and such). Your software will do all this for you, you just need to make sure you understand whats going on in there.

You might look at this way. Your GPS system (JAVAD) doesn't keep or store your data in SPC, it projects your data in SPC because you set it so. It will just as well project the data in some other projection (ground oriented LDP, UTM, some other SPC). Just set it so, change it back and forth, whatever.

Work in grid. Just grid. It's really difficult to jump back and forth.

It would be no trick to create a custom Caddo Gap zone and just work in that. The difference between grid and ground would then be negligible.

I started with LOCUS l1 units. They output a SPC file, that was real. (Real SPC)

From there, I studied the output sheets, and picked an average elevation, and an average location for my project, and developed a CSF (Combined Scale Factor)

I think I want to STAY in SPC. BUT I want my final plat to be on ground. (most of the time)

So, it goes like this with JAVAD:

Set up and start base. With correct slant height.
Do all my work.
Come home.
Hook LS to internet, after midnight. About 3 minutes later, it says "Move N 16-14-37.256 E 3.729 ft. And, Go UP 7.639 feet.
OK to adjust?
Yes.
NOW the whole days work is all SPC.
Now, I download it on a Thumb drive, ascii file.
Open it all up in Carlson.
go back to LS, look up CSF for BASE, or any other point, or an average of ALL the shots in that file.
It gives me Grid to ground, CSF.
Back to Carlson, and scale it all, by that factor. 102 PPM (1.000102) and now it's all at ground.
Now, I want to send line work, and points back to LS.
So, I 1/x (Flip over the scale factor) and, it is a number slightly less than one. I scale EVERYTHING (Don't forget to turn on frozen layers!). points, lines everything. Now all of it is on SPC again. Then, I say "Update the points, from the cad file". Now the coords are BACK on SPC too.
Now, I can upload it all into JAVAD, to stake. And, go hunt for more corners.
Back in, we get a new base coordinate. (Javad forces you to make a new base file every time.) Now, DPOS says "MOVE S 21-13-13.259 E 0.022' and DOWN 0.031'. OK to adjust? No.
Back to the carlson, we down load fresh coords, and scale them back to surface. Do more work. Scale back to SPC, and go set final boundaries. It is VERY important to always use the correct scale to go back and forth, grid to ground, and ground to grid.
This will thoroughly screw things up!
Anyway, I understand the basics of it. I just don't have a SMOOTH way to do it all.
I want CARLSON to work in SPC, and to ANNOTATE on any CSF I tell it. AND any rotation I want.
I think long term, that this would be good.

Nate

On some slow cold day you should experiment with changing the projection in your JAVAD file. It will do practically (if not the same) thing as all this scaling you are doing. After you have done your scaling in Carson (your CAD) go back to the JAVAD and change the projection to match your Carson stuff. Then compare the coordinates. It might take some effort to figure out the projection parameters needed in the JAVAD but I'd think the JAVAD folks would help you out here. Once you figure it out I'd expect you won't be running all you coordinates back and forth through some extra scaling routine, there is just no need for that.

I spent a few years doing almost all my work in SPC. As far as I'm concerned not much need for that dinosaur anymore but hey, it's only a few clicks away should I need it. Should I want all my bearings at odds with the original GLO, state highways, RR's, and most deeds with the added benefit of the distances shown short YUP, just a few clicks in a computer.

I have one engineering firm I do some work for that wants UTM's. So I give them a grid based ground file (topo) for close to actual data and then, a few clicks away they get their UTM points file for what ever reason they want it for.

You will get a lot of solid advice on this forum. Keep in mind the experiences, purposes, equipment, laws and customs vary WIDELY. You will need to filter out things that don't fit your circumstances.
I work in several states. That means different units, projection types and distortions. While some local tricks are handy I find it best to use a simple and consistent work flow.
Before visiting a site, I compute an SPC combined factor covering the township. If there in no legacy data to be concerned with I stop there and go to work. We use the combined factor applied to whole ordinates to keep the math simple. We use file and folder names to distinguish grid versus ground. All data is gathered and processed in SPC but expressed at nominal ground. Regardless of flow we maintain grid bearings. Conversion to true is quite simple without the pesky issues of qualifying a true bearing systrm.
If we are doing work that requires it, we do process using proper (textbook) techniques. This is limited to BLM or USDA work.
Just my random thoughts. Good luck, Tom..

Nate, You could run completely in SPC and using Carlson's Survnet process the raw data to spit out both SPC and ground coordinates. Then just import the SPC back into your device and work with the ground plane coordinates in Carlson. One other thing that you should pay attention to if you use carlson survce for your total station work, Set it to traverse on SPC, then look at the raw file. It records the actual distance measured which is the ground distance. I caught this because I though survce actually scaled the distances to spc in the raw file but they dont it calculates the coordinates to SPC only, and i double dipped on the scaling. Luckily I caught it.

Here is how we do it...

1. Set up data collector with projection details. In our case all are Transverse Mercator, some using a scale factor, and with differing meridians

2. Load data collector with known marks. Previous surveys, boundary and road line work etc is also useful as a guide

3. In the field find a known control mark and record observations.

4. 'Site Calibrate' data collector to this mark - that is Trimble speak setting up a local translation.

5. Observe at least two other known control marks.

6. Compare measured positions with calculated and confirm errors are within acceptable tolerances.

7. Complete field observations.

8. Export data from collector to computation package.

9. Calculations, new points, linework as necessary.

10. Export back to the data collector for any field setout.

11. Export to drafting package for plan preparation.

Some Notes:

we are a Trimble shop, using TSC3 R10 S6 and S8.
We do have Trimble Business Centre but we use 12D for calcs.
We use AutoCad Light for drafting.
Exporting is done in CSV, DXF, Trimble Job and 12D field file formats.

NZ is fortunate that almost all old surveys were done on TM projections with given meridians. We dont really have an issue with having to match to surveys done on magnetic or assumed bearing origins. While we have at least thee control marks, we only use a single base point for calibration. Using only one means points are simply shifted X and y. More than one can introduce unwanted rotations and bearing swings

The process I generally follow is:

1. Collect GPS data as static observations, and/or RTK in SPC, and total station data at ground.

2. For static GPS, process vectors in TBC using ITRF using day-of seed positions from OPUS Projects, OPUS-S, and/or OPUS-RS.

3. Export static vectors from TBC to ASCII format, and/or export RTK vectors from the Javad receiver in g-file format.

3. For total station data, convert the raw data file to Star*Net input format.

4. Import GPS vectors into Star*Net.

5. Constrain selected control points to NAD83, using published or OPUS values, as appropriate to the project.

6. If ground coordinates are desired, set up Star*Net to rotate, translate and scale as desired.

7. Run the Star*Net adjustment.

8. Export ground coordinates from Start*Net to ASCII format.

9. Import ASCII ground coordinates into CAD.

10. If stakeout is needed, export ground coordinates from CAD on ASCII format.

11. Import ASCII coordinates into data collector for stakeout.

12. I've not used RTK for stakeout yet, but I *think* the Javad can create a custom projection on the fly to allow the ground points to be staked in SPC. I need to look into this when I get time.

Thanks everybody. Yes, I can get ground coords from the Javad LS. It is just a few clicks. (If I only could remember which ones! Wink) As I think about all this, I want to be able to seamlessly do all things. It seems handy to be able to do the Annotate Rotated, and to do the Label with Scale Factor, in Carlson desktop.

Nate

Carlson Survey will annotate using a scale factor. I'm not certain which version they added the feature, but you can leave coordinates in SPC and annotate line distances with an applied scale factor that you enter for the project. You probably still need to be aware of scaling factors for input distances when calculating. I don't think the scale factor is applied to offset, extend, circle radius, etc.