According to the Promark 2 manual, when establishing control, let's say with three units, you need to turn all the units on at the same time. My question, how can one person accomplish this? Are they talking seconds, minutes, etc.
Thanks in advance for you knowledge....
The units need to be on and occupying 3 different locations at the same time in order to use downloaded information from the same satellites in order to compute their locations in respect to each other with any redundancy.
It can also be helpful before occupying the locations to have the all the units turned to assure they all share the same settings.
The note does not mean that it is necessary to turn all 3 on at the exact same moment in time for them to work properly.
Turn ProMark 2 On and Move On
Turing on all units at the exact same time is necessary only if you are going to occupy as many points as possible and use all the memory before downloading. I have never worried about the limited memory because it is several days of occupation time.
I have 3 ProMark 2s and that is all I had for quite some time. The only thing you worry about when turning them on is that the last units turned on is the unit that controls the session time. Assuming you are only occupying 3 points close together and will live with the minimum "3 Mile" solution, about 25 to 35 minutes. The "# Mile" solution is internally calculated based on visible satellites. I believe the algorithm also includes satellite geometry but I have never had a problem with it, so I don't worry. I have occupied whole chains of points with 3 PM2s by the following method. When the 3rd unit turned on shows a "3 Mile" solution I return to the 1st unit, turn it off and move it. When the 1st unit, 4th occupation, shows "3 Miles" I repeat the procedure at the 2nd unit. This can go on all day long and never fill memory at the default 10 seconds. If you have NGS or other monuments in your observation list and want elevations, double the occupation time or at least max the mileage "12 Mile" solution. Suppose you want to tie in 2 off project monuments and I assume they are much farther from your project than your project size, having run a while on your project move 1 PM2 to an NGS monument, occupy for the required distance, then move one project PM2 to a second NGS monument, occupy the required time, then move the 1st NGS PM2 to the last occupied project or another project point and go the required time. Then move the other NGS PM2 to a project point. Note that you have a project point with a very long occupation that is tied into both NGS and several project points with longer occupations, this should be your control point. Once you have downloaded and progress to a network solution you may find some short duration vectors. Either exclude them by setting a higher minimum vector time or specifically select those vectors for exclusion. For an all day project close the day out with some reoccupations, remember to use the same point name and make sure your antenna heights are correct. An incorrect antenna height can actually create occupation location errors. Trust me, I found out the hard way, once and never again. For that project I had borrowed 2 PM2s and did not have fixed height setups for them. With 5 PM2s I found out that with the time required to take down, move and setup again, I could get not more work done that with 4 PM2s. I would say 4 PM2s maximizes efficiency for one man, and using only 3 is no great penalty.
When doing only 3 points with 3 PM2s, I turned them off in reverse order, with the first 1 on being my chosen control point. I would download 3 CORS, calculate and mean those 3 positions for control. I would then add my other PM2s, hold my PM2 control point fixed and get CORS control tie checks. Sometimes my other PM2s were too short duration for a fixed solution.
These days I most often go to a personal project with 1 or 2 legacy Z-12s and all 3 PM2s. My usual setup is 2 Z-12s and a single PM2. But since things can go wrong with the older Z-12s I sometimes use a second PM2. When everything that can possibly go wrong with Z-12s, batteries internal and external, I know I can still get the information I need with the 3 PM2s. These days I have 4 fixed height, 3 legged bipods, so 4 points (usually for projects with or for others) are done. Most I have ever done, several times is 3 Z-12s and 7 PM2s, 10 points simultaneously. Usually that is a 3 man job, and enough job time for 3 2 hour OPUS observations, 2.5 to 3 hours or say 1,2 day. On occasion we have gone to 14 points on a project, not all simultaneous. I have also in the past worked with a surveyor and his 2 Leica 1200s. In that case I switch to match his 5 second observations, not that it is necessary but it saves him asking any questions.
BTW, what will you use for post processing, Ashtech Solutions, GNSS Solutions (both end of life support) or something else?
Paul in PA
Turn ProMark 2 On and Move On
> These days I have 4 fixed height, 3 legged bipods
I prefer fixed-height 4-legged tripods, myself. 🙂
Turn ProMark 2 On and Move On
I use GNSS Solutions...thanks Paul and Mr. Harris....
Have You Used The VRS Option?
If PM2s are all you have, use the VRS option at your selected Control Point position. Create a RINEX file from the created VRS file and submit to OPUS or OPUS-RS. Heck I even extrapolated L1/L2 files from a PM2 file and gotten OPUS-RS solutions, but that is much to much work top do on a daily basis.
Paul in PA
Have You Used The VRS Option?
Yes, PM2's are it...I'll try the VRS option and submit, thanks Paul, you are a wealth of information concerning the Promarks...thank's again..(I'm not forgetting you Mark Silver)
Have You Used The VRS Option?
Paul, (not to hijack this thread if this question has that effect...) when you send the compiled file for the VRS point back to OPUS, how different is the OPUS derived position from the one that GNSS Solutions calculates for the VRS point?
Unless you purposefully choose reference stations that are different from the ones that OPUS will use, is it not likely that they are post processing the file against the same stations that the software used to compile the file?
Just wondering...
Different Software Can Give Different Results On Same Data
Since I choose the closest 3 it is probable that OPUS does also. Essentially you are getting an independent check on your position.
Now sending it to OPUS-RS uses a third software. 9 CORS in OPUS-RS can give me a much better vertical with less work
There are some clients that are so used to OPUS reports that having one to show them makes them more comfortable with your work.
Paul in PA
