USING CELL MODEM FOR A BASE AND ROVER RTK SETUP??

It is, but it is slightly complicated by the cell phone in the base having an 'inside IP address' which can't be routed to from the internet. There are a few solutions:

o Carlson has a tool called Listen/Listen where the base sends corrections to a server that 'reflects' the base corrections back out to one or more rovers.

o CHC has a built in service call APIS that does exactly the same thing.

o It is fairly simple to setup a 'reflector' behind a static IP(, or an DynDNS IP address) that accepts the corrections and then re-transmits them. I have successfully used the LeFabure NTRIP Caster for years to do this. Another common tool is SNIP.

o Ashtech used to have a dedicated tool (Real Time Data Server: RTDS) to do the reflection also.

The problem with all of these scenarios here in Utah is that the cell network is not dense enough outside of the cities to have decent coverage for most areas. So you end up fighting cell coverage most of the day, thinking about how great it would be to have a UHF link back to the base.

What part of North Texas are you in? Western Data Systems has an RTK network that covers a good deal of north-central Texas and southern Oklahoma. Here's their coverage map: http://wds-us.com/coverage-map/

I live in baylor co, work north up to red river and generally about 150 miles every other direction, more southerly than east but do go west to near lubbock area, I am a former Txdot employee, but I left there in 2003, prior to them getting their network setup for cell rtk, but i was personally involved in helping to get networks in some of the txdot facility in Texas, which are also available on all of the post processing sites, just wish they had a subscription scenario for private surveyors, as i think it is currently only available to contractors and txdot employees, basically they have a network receiver every thirty miles or so, with exception to far west texas
i will check out the wds site and see what it says,
thanks for the info

thanks for the info, I read JT Stricklands post or reply regarding a similar issue from some time ago, he does this exact thing, with similar techniquess and processes that you mention, cell coverage is generally good where i work with a few exceptions, nothing that a cell booster could not help fix, I know these units i plan to buy have wifi also, curious if that could not be used for this process somehow, otherwise not sure the benefit of it yet Just seems to me this could be some sort of field process, but maybe it has to bounce off of some gps static network somewhere, to me that is kind of what purpose my base unit is serving as out in field, currenty less the cell modem, i am just a wanna be radio guy and know nothing really, but I have been reading up on how the radios work and they must have some sort of trigger that starts and stops a data packet or something, which is where the eot timeout steps in,I am not looking for a full replacement or to do away with radios, but with the restrictions that fcc has placed on the frequencies, the ability to survey more than 2 to 4 miles is almost not there unless at night and setup on a bluff on the caprock, I have been thinking of this for years, but had no way to implement it, without purchasing new equipment, but now that has become a necessity i now am interested in finding out more about this ability to help me purchase the right equipment, as i am low budget guy, but very blessed, happy and thrilled to be doing what i am doing, so either way it beats almost every other job in the world, just always looking to improve what is already a wonderful life

You must have a backdoor into TxDot RTK
I use downloaded TxDot data for static and here it is just less than 2 meters off of actual location as compared to results from CORS.
My best results at the rover is in the region of 3-4 mi from two user control points.

I bought a mobile hotspot to which I connect my base, and I paid Verizon $500 for a fixed IP address. That seemed kinda like highway robbery, but since Verizon covers most of the areas I work, it's been worth it. I do have a 35w UHF radio, but using a TCP connection gives me better coverage and a simpler (and much lighter!) setup.

Jim Frame, post: 451336, member: 10 wrote: I bought a mobile hotspot to which I connect my base, and I paid Verizon $500 for a fixed IP address. That seemed kinda like highway robbery, but since Verizon covers most of the areas I work, it's been worth it. I do have a 35w UHF radio, but using a TCP connection gives me better coverage and a simpler (and much lighter!) setup.

THAT IS VERY INTERESTING SCENARIO, THERE MUST BE A LOT MORE INVOLVED TO IT THAN THAT, OR IS THERE?? THIS CELL NETWORK THING IS BRAND NEW TO ME, THE STATIC IP ADDRESS I HAVE HEARD OF BUT HAD NO IDEA HOW RELATED TO NETWORK RTK. IN MY AREA THERE IS NOT CURRENTLY NETWORK RTK, ALTHOUGH IT IS ONE COUNTY AWAY, AND I MAY HELP GET IT TO MY AREA, SIMPLY FOR THE EASE OF ONLY USING ONE UNIT, MOST OF TIME, EVEN IF IT WERE IN A COUPLE OF COUNTIES I WORK IN IT WOULD NOT BE COST EFFECTIVE AT 2000 PER YEAR TO JUSTIFY PURCHASE. THIS IS ONE OF THE FEW NEGATIVES OF LIVING AND WORKING IN A RURAL AREA, AS IT KEEPS ME ON THE ROAD MOST OF THE TIME AND PUTS A LOT OF MILES ON VEHICLE, BUT WOULD NOT TRADE IT FOR THE OTHER OPTION, SO ATTEMPTING TO LEARN NEW IDEAS AND TECHNIQUES THAT WILL HELP ME OUT OVERALL IN MY WORK

THANKS AGAIN FOR YOUR INPUT, I AM VERY INTERESTED IN KNOWING MORE ABOUT THIS, I WORK BY MYSELF WITH OCCASIONAL BENEFIT OF WIFE (SHE DRIVES ME AROUND WHILE I WORK OR SLEEP IN BACK SEAT)

WHY ARE YOU YELLING AT US?

A Harris, post: 451331, member: 81 wrote: You must have a backdoor into TxDot RTK
I use downloaded TxDot data for static and here it is just less than 2 meters off of actual location as compared to results from CORS.
My best results at the rover is in the region of 3-4 mi from two user control points.

iT IS MY UNDERSTANDING ACCESS TO TXDOTS NETWORK IS LIMITED TO EMPLOYEES AND THEIR CONSULTANTS ONLY, I HAVE NEVER INQUIRED HOW TO ACCESS IT FROM ANYONE, I DON'T HAVE ACCESS TO IT, BUT SINCE IT COVERS THE ENTIRE STATE ONE WOULD ONLY PRESUME THAT IT WOULD PROVIDE A VERY CONVENIENT AND USEFUL TOOL FOR SURVEYORS, I HAVE TALKED TO TXDOT SURVEYORS AND THEY LOVE IT, I SOMEWHAT UNDERSTAND THE POSSIBLE PROMLEMS AND ISSUES THAT COME WITH LONG DISTANCE RTK MEASUREMENTS, WHICH IN THE CASE OF TXDOT WOULD PUT THEM UP TO 15 MILES ATLEAST AT TIMES, I HAVE NO IDEA WHAT HAPPENS IF A PERSON GETS 30 MILES FROM A NETWORK BASE, DOES IT ACT LIKE OVER EXTENDING A UHF RADIO?? A PERFECT SCENARIO IS LIKE FOR A MIDSIZE CITY WHERE EVERYTHING CAN BE SURVEYED FROM ONE NETWORK LOCATION IN A 5 MILE RADIUS, I HOWEVER DO NOT WORK IN THAT KIND OF BUBBLE,

ONE DAY I MAY BE IN ABILENE, NEXT DAY IN CROSBYTON, NEXT IN VERNON, NEXT IN HENRIETTA, WHICH MADE THE RADIO SCENARIO PERFECT AND STILL A FUNCTIONAL SCENARIO, BUT SINCE I NEED NEW EQUIPMENT I WILL NOW BE FORCED TO FIT WITHIN THE 12.5 MHZ SPACING THING, WHICH IS STILL BETTER THAN A TRANSIT AND PLUM BOB AND MEASURING TAPE OR EVEN A TOTAL STATION, BUT I AM NOW SPOILED AND IT SEEMS KIND OF CRAZY FOR TECHNOLOGY TO BE SO MUCH BETTER BUT TO HAVE TO TIE ONE HAND BEHIND THE BACK BY FORCING THE RADIO LIMITATIONS ON SURVEYORS
MAYBE TRUMP WILL LESSEN THOSE REGULATIONS ALSO, I AM ONBOARD WITH THAT
SINCE I AM A TRUMP FAN, I WILL SEND HIM EMAIL OR TWEETER AND SEE WHAT HE SAYS, I MAY EVEN TRY A FACETIMER

sirveyr, post: 451342, member: 6680 wrote: WHY ARE YOU YELLING AT US?

My typing habits are almost as lazy as my writing habits, but I will try to lower the tone a bit, thanks for letting me know, this is my first day on board, so I will attempt to not go against the grain, i also need to trim my fingernails, that usually helps too

RUSSELL RIVERS, post: 451341, member: 13111 wrote: THAT IS VERY INTERESTING SCENARIO, THERE MUST BE A LOT MORE INVOLVED TO IT THAN THAT, OR IS THERE??

It's a Javad system. The Triumph-2 base receiver connects via WiFi to the mobile hotspot and pushes corrections out a TCP port to the hotspot's fixed IP address. The Triumph-LS rover connects to my phone (which I set up as a mobile hotspot) via WiFi to receive the corrections.

I needed a lot of help getting all the settings right -- the Javad support guys have been great in that regard -- but now I just turn everything on and go.

That is fascinating, I have no doubt complicated, unless a person knows all of the ins and outs needed for the two units to talk to each other, but definately gives me a direction to look down, certainly gives good reason to purchase a unit with wifi and internal cell modem, I greatly appreciate the information and I may have a few more detailed questions for you after i look into this process a bit,

When I first started with RTK Cell we bought a cell phone for the base and one for the rover. We were using Leica 500 series. If I remember you had to dial from the rover and the base answered automatically. Then we swiched to a cellular data modem. In that configuration we needed fixed ip address because we had a cors station perm. fixed at the office and restricted it by ip address. I can only remember using the cell modems a couple of times in the base rover mode. But yes it should be possible. And those old phones were the flip phone.

We have the Leica GS14 Base Rover Setup and Use an AT&T Static IP for the base. AT&T only charged us $5 for the static setup and it works like a charm and requires very little bandwidth (3g is fine). We really like the Base Rover solution because we are able to record baselines and when we do the NGS double occupation method, we can bring that data into StarNet for analysis and reporting.

There is a difference between using cellular for communication between base and rover and accessing an RTN. In one scenario, the base has an IP address that the rover looks for on the internet. As Mark explained, the base needs a static IP address for the rover to be able to find the corrections. Or, the base can transmit its corrections to a server with a static IP. Getting a static IP from a cellular carrier can be a lot of trouble (but offers some real advantages). Using a server to reflect those corrections back out will offer more flexibility in getting that static IP from other providers.

In the other scenario, the rover looks for the RTN with corrections provided by others on the internet These corrections are supplied using NTRIP which has a mountpoint for a particular correction message or TCP which has a particular port for a correction message.

In one scenario, you provide the corrections, in the other, someone else provides the corrections. Both are transmitted over the internet via cellular.

I would recommend maintaining some sort of independence from cellular. It may be the best way for 99% of your work, but there will be those occasions that you will not have cell service. A small one watt radio would provide you with an alternative in those rare situations. It could even be a license free FHSS (frequency hopping spread spectrum) radio. Typically you will be able to get around a mile (sometimes less, sometimes more) with a one watt radio. Use the cellular for most of your work and use the one watt as needed.

I have the a similar setup to Greg's. For a point-2-point solution Leica has a very easy set up. Basically the Base modem is just treated like any other radio. You set the parameter up to connect to the wireless network. I can second Jim's comment on Verizon's highway robbery. I think AT&T charges me $3 a month extra to have a static IP on their IP.Gold network. If you want to access an AT&T static base using an AT&T rover, both need static accounts.
In areas with cellular coverage it performs much better than a radio, you just need to recognize the limits of the single base RTK.

John Putnam, post: 451506, member: 1188 wrote: I think AT&T charges me $3 a month extra to have a static IP on their IP.Gold network. If you want to access an AT&T static base using an AT&T rover, both need static accounts.

In fairness to Verizon -- which I offer grudgingly, since I consider Verizon, AT&T and their brethren to be predatory oligarchs -- the $500 fee reportedly gets you up to 10 fixed IP addresses. I've only needed 1 to date, so I haven't verified this.

When I had it, Verizon said it was good for all of the line on our account.