It would seem that this is great so long as you have some way to connect to the DPOS server, i.e. if you are using a cell phone modem or something. What happens when you're out of cell phone service? Not knocking it, because GOD knows I'd love to use a service like this; however, if I have to use my base, then I have no cell service and if I have cell service, I have my R10.
Or am I totally missing the boat on something here?
I agree Duane.
We certainly must trust the technology, as we all do. Else we would still be doing hand calculations. Which is nearly impossible to do the calcs needed for GNSS computations. There just needs to be a balance between the button pushers and enough meta data sent back to them in order to analyse the results. I'm sure Javad's system will provide many statistical values, for which the average end user may not understand. Javad may even provide nice big RED flags, stating these results are poor due to short occupation times with very long baselines.
I have followed many construction projects where the original topo was performed with a network GPS by licensed surveyor firms, where the results were incorrect due to a mis-understanding of technology. Such as choosing the wrong datum, wrong projection, no Geoid. Or with static surveys I have seen those whom use no post processing at all and using an autonomous position, using CORS stations too far away, poor geometry in the network, or too short of occupations.
Kris Morgan, post: 359624, member: 29 wrote: It would seem that this is great so long as you have some way to connect to the DPOS server, i.e. if you are using a cell phone modem or something. What happens when you're out of cell phone service? Not knocking it, because GOD knows I'd love to use a service like this; however, if I have to use my base, then I have no cell service and if I have cell service, I have my R10.
Or am I totally missing the boat on something here?
Not a bad question. I wouldn't suggest this is a cure for all ills. If you have access to an internet base (RTN or a roll-your-own) and good cell coverage, then you may not need this feature very often, unless you find one place that the rover just can't get a good cell signal in. In that case, log the raw data, then head back to the base, download it and ship it to DPOS to solve after the fact. It's not real time, but it gets you an answer while you are in the field. If it's an RTN, then you can't really head back to the base, which leaves you processing to CORS (similar to OPUS, but processing at higher rate when available and processing Glonass as well).
This is speculation on my part, but I believe the post processed solution will provide a more accurate position than RTN. I could be wrong about this, but I'm encouraged by what I have seen already at 9.5 miles.
I suspect that this feature will largely be used by those in remote areas without RTN access, without a cellular based correction, or with a low power modem requiring occasional longer range measurements. That lower cost, license free frequency hopping spread spectrum solution starts to become a more viable option for some.
One thing that I am looking forward to testing is the comparison between RTK and post processed. For a brief period with my old system, I would take the time to process the raw data from my Altus receivers that I collected during my RTK observations in Ashtech's GNSS Solutions as a Stop and Go file. I was cobbling together a lot of software (using Carlson's raw file to generate the stop and start times and using a little of my own code to generate a D-file that Solutions would use to break up the continuous raw file) and then manually comparing between RTK and S&G in Carlson Survey. It was a real chore and I ended up dropping this approach after a while. Much of the cobbling I was doing can be automated, getting me straight to a comparison. What will the value of this comparison be? How independent is a forward and reverse post processed solution from an RTK solution? I don't know the answer to that one yet, but it's a question I'm excited to explore.
Kris,
You are correct that cell service is needed at some point to obtain the DPOS adjustment.
A cell connection is not at all needed for field work, which can use UHF, WAAS corrections, or be completely autonomous.
I usually have cell service, and normally choose my own base anyway. This provides me with much faster fixes in the woods, and a significant improvement in precision as compared to our VRS.
leegreen, post: 359628, member: 2332 wrote: I agree Duane.
We certainly must trust the technology, as we all do. Else we would still be doing hand calculations. Which is nearly impossible to do the calcs needed for GNSS computations. There just needs to be a balance between the button pushers and enough meta data sent back to them in order to analyse the results. I'm sure Javad's system will provide many statistical values, for which the average end user may not understand. Javad may even provide nice big RED flags, stating these results are poor due to short occupation times with very long baselines.
I have followed many construction projects where the original topo was performed with a network GPS by licensed surveyor firms, where the results were incorrect due to a mis-understanding of technology. Such as choosing the wrong datum, wrong projection, no Geoid. Or with static surveys I have seen those whom use no post processing at all and using an autonomous position, using CORS stations too far away, poor geometry in the network, or too short of occupations.
Yes, even with automation it's really not a button pushing thing, if done correctly. I have compared DPOS with OPUS in challenging areas (nearest cors 25 miles, tree cover, mountains). Long occupation times are needed, but even then OPUS doesn't seem to work as well as DPOS. Mostly it shows up in the vertical. DPOS is using different algorithms, much like personal post processing different users might end up with slightly different answers depending.
leegreen, post: 359599, member: 2332 wrote: Shawn,
I really like the ideas Javad has brought to the hardware side of GNSS system, but the cogo routines, and lack of robotic/optical instruments collaboration is just NOT there. If we could combine the Javad GNSS hardware with the cogo and field applications of Magnet or Carlson, it would be a very efficient set of tools in the surveyors bag. I feel Topcon is getting behind in the hardware market of GNSS technology. When compared to other vendors, the GR-5 and Hiper V's are too heavy, too bulky, have no slope sensor, no camera, and lack of other features recently introduced to market. I was hoping [USER=8922]@pmoran[/USER] of Topcon would enlighten us on what Topcon may be doing in this area. I have always believed not one vendor will make a single best product, it takes others to push them and help us all advance in technology. There is not a single magic tool that can do it all, but a well equipment tool box with the a properly selected set of tools that with make us most efficient.
An example: Everyday I bounce between multiple software's such as Bentley InRoads and Carlson Takeoff on the same project, because I know one software has a more efficient routine for the task at hand. As these products mature and one vendor creates a new routine, we often see a similar routine adapted by the other vendors in future upgrades of their software and/or hardware. This is what I see Javad doing for today's market in GNSS.
Topcon and Sokkia are very much the leaders in Hybrid Positioning- Magnet Field remains connected to a network rover and a robotic instrument at all times allowing seemless and stress free toggling between the two sensors. The localization process is either automatic or user controlled. There is one icon at the top of the screen that allows the surveyor to choose GNSS or optical measurements. Magnet Tools allows the surveyor to process all relevant data at one time and if CORs data are required that process has been automated too. Magnet Field is leading the way in Hybrid - without a doubt.
Progress. It's like that. Word processors. Calculators.
They make the Complex easy, and the easy complex.
I did a demo of the LS yesterday. For another surveyor. We stuck it in a cedar tree, and shot several shots, that agreed with each other by up to 0.04'.
It's the cats meow, for RTK.
I'm excited.
It's still RTK. But, it's the best RTK to hit the market.
Nate
I am thinking.... How This might work.
I have an android based phone. It gets good signal, on most hills around here. It is VERIZON. This is "Verizon Country".
I can use this android to control the LS, via RAMS. It can also MAKE a little MiFi. It becomes the "Internet Portal" for the LS. During these little episodes, it uses battery fairly fast.
So... with my current configuration, and with an external power supply, for the cell phone, (Which CAN BE SUPPLIED via a cable to the LS!) or a cable to the base battery, or a cigarette lighter plug on the ATV, or truck.
Thus, I already have the components to do this new Post Processed, Static shot. I just have to learn it, and apply it. We are gonna need a name for it.
I already have learned alot. When's it gonna quit? I think you cease to be a surveyor, when you stop learning.
OK, here is the big question, will the next release of J-field be here Monday? 🙂
N