I do not do much RTK, and have never used it other than with a base radio (except for VRS).
I have an application where being able to use a cellular link between the base and rover would save me a lot of time, and using a radio solution would not be feasible.
So, how is it done? What I have available is a Mifi at one end (base?) and my Droid phone at the other end. Obviously both have access to the internet. I have used both for VRS. But how does one create a link between them without a fixed IP? Or maybe this isn't the right equipment for the job. In the old days, when cell phones were more like modems I could see how this could work-the rover dials the base, logs in, and begins to receive corrections.
a possible solution-not sure if it exists
I think one way to do it would be to have software running on a office computer (with a fixed IP that would receive the RTK corrections from the base, and "re-transmit" or forward them to the rover.
Does this exist? Other than high end VRS server software, which is not needed in this case.
Maybe something like this:
Thanks, Gavin. This would have to be very mobile, and would occupy any given point for hours or maybe a full day.
When I got my first cell modem (a pcmcia card) many years ago, it came with a fixed IP address.
The application I am looking at is to take elevation check shots over a large area, often a county or several counties. I do all my photo control and Lidar surveys using fast static from a local base, within 15 km. But, that is overkill for the check shots, and I consider RTK to be the appropriate technology. But, the radio would be the limiting factor. Of course this is ideal for VRS, but some of the areas do not have VRS.
Perhaps setting up an NTRIP server would be a good way to accomplish this.
We belong to a network Superior Network
I haven't set-up a base in years..thank god.
Of course once L.S. comes online we'll be back to chain and theodolites 😉
TSC2 base options?
If I create a new style, and set base radio to internet connections, then go into the dial profile screen, there are two options under base operation mode:
Operate as a server
Upload data to remote server
anyone know how these work or where I can find documentation?
I subscribe to Keystone, which has a pretty large coverage area but this is outside of that area.
TSC2 base options?
This option has been around in Vancouver,Canada for a long time now.Cell phone in pocket....run w/rover.
Surprisingly accurate,bases stations often on Fire Dept's and City Bldgs if I remember correctly .We used to monitor the preloads w/this setup..
Gotta' love technology.
🙂
> The application I am looking at is to take elevation check shots over a large area, often a county or several counties. I do all my photo control and Lidar surveys using fast static from a local base, within 15 km. But, that is overkill for the check shots, and I consider RTK to be the appropriate technology.
Minor hijack: I'm curious about what kind of accuracy specification you have to meet for the check shots, and how well RTK conforms to it.
I don't have a firm number.
When I am doing the actual control, I try to keep it under 3 cm.
But, this is to compare against the final product, which in this case is 15 cm RMSE.
Since we can pick wide open spots, I feel confident that an observed control point (Trimble terminology) should be ± 5 cm at worst.
In the past we did the check shots by static as well, but they are now specifying so many that I felt we should try alternate methods. They might ask for 8 control points and 100 check shots for a typical project. .
This is possible with my current Leica gear, BUT I am using a Seimens modem on each end that can either do dialup or IP, it is somewhat carrier dependent too as not all carriers support circuit switched dialup. I have been doing this for about 10 years, but less and less, since if I have wireless service I just use a RTN and if I don't I have to use the radio anyway. You might want to see if other RTN's cover your area, I have been known to drop $600 on a project just to use a foreign RTN for a few days (the minimum term of service was 90 days). No pointers on how to do the dialup task with your hardware, so not much help there, just relating my experience that it can be done.
As far as your project, what you want to do would be single baseline RTK and at some point the wheels may fall off that due to vector length even if you can get the comms to work, BUT I am sure that isn't news to you 🙂
SHG
Shelby-Thanks. That is the conclusion I had reached after some research-that you needed phones capable of circuit switched data connections. All the phones I have are packet switched, i.e. no direct connection between phones (as far as I can tell).
I had occasionally come across base stations at airports that had a phone tethered to the unit.
If I had the time I would look into setting up my own NTRIP server and caster, seems very do-able. Maybe if the work dies down a little this winter-but it never does (that's a good thing, I guess).
