Affordable RTK Receiver

Try bad Elf.?ÿ I'm not repping for them but in the real world it's probably your best option with the price and features you're seeking.

Your dilemma will be work flow and follow on data management and and and.....

The higher cost isn't always a legitimate up charge but sitting down to flesh out the bigger long term goal on geospatial data collection and goals for it's use are always overlooked until you buy something that has a short life span in software and hardware regardless of the inexpensive possibilities.

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A Javad triumph 2 with Javad Mobile Tools running on a tablet would work. You can also output nmea messages now to be used with arcpad.?ÿ

Posted by: @shildebrand

i have my eye on a the polaris s100.?ÿ

I know a guy who has an Emlid Reach, which is in the same price range as the Polaris. His complaint with his Emlid is the radio range between base and rover. Less than 1/2 mile in practice. That, and he doesn't find it to be all that user friendly.

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The answers above are valid but overlook one of your stated requirements, namely: cm accuracy.

You cannot obtain cm accuracy from any unit on the market without some sort of correction source to take the inherent randomness out of an autonomous position.?ÿ That means either another receiver to run as a base or more likely, a network correction source.?ÿ Centimeter level positioning is, by definition, a precise position and you can spend quite a lot to get from the submeter WAAS corrected units widely available today to the centimeter positioning you say is a requirement.?ÿ Is that level of accuracy specified by the work you're doing??ÿ If so, what sets that specification??ÿ I was testing a Juniper Systems Mesa2 a couple of years ago, and using the internal WAAS corrected GNSS solution built into the computer, the distance between two observed points checked within less than 7 centimeters. That should be plenty precise for most GIS-type work.?ÿ Don't know about the internal GPS in iPhone or Android devices.?ÿ They certainly are not going to provide accuracy statements.?ÿ Connecting to the app you're using is likely a separate issue.

Looking at Polaris s100 website, that isn't true RTK. If I understand correctly, in order to obtain corrected position the data must be submitted to their online PPP/PPK post processing application to obtain the correction to achieve cm accuracy. It's not real time corrections like you would get running a base/rover. I work for utilities and I've seen them attempt going this direction with their construction field crews using the Trimble Juneau and the results were less than desirable because the field guy collecting data barely has a clue what they are doing and getting the data post processed is a PIA for them. Combined with no QC protocol, it pretty much guarantees me job security.?ÿ

Not sure if this would work for you, but a software-defined receiver solution like Trimble Catalyst would be a lot less up-front cost, and just a subscription thereafter. It does require a real-time network to connect to.

@williwaw?ÿ ?ÿCorrect, it is a Network Rover. Conventual RTK has to be done post processing, you can use the base station's corrections (which came from the network) or you can download the network's corrections directly. You have to convert to Rinex .obs and .nav files to process in your own GNSS software. How are the corrections your base station provides different from the corrections your network service provides?

Hi Shayne

I do development of low cost precise devices using GNSS.

I recently developed a unit single frequency L1 that is decimeter accurate in autonomous mode. The unit is operational but requires a lot of refinement.

If you are interested feel free to message me

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You don't need cm accuracy. A $300 Garmin will provide all the accuracy you need.

https://emlid.com/reachrs2/

This receiver (with base & rover units) will deliver all except #3.

The User Interface is improving but it does have a steep learning curve esp for someone with no surveying/GIS experience.

There are numerous 3rd party apps that can be used in tandem with these units and Field Genius has released an Android App/Software that also works with these units.

I am told that SurvCE is also compatible if the NMEA feature is used.

Cost for the Base & Rover RTK pair is under $5,000

Data can also be post-processed for greater precision

I have no share in this company - just a satisfied user

If you are collecting data that your GIS dept. would normally collect, why not purchase the same equipment they use? Then you could have seamless workflow.

@norman-oklahoma?ÿ

If you have cellular data, you can set up Emlid Ntrip caster (no cost service).?ÿ

Reach view app is limited.?ÿ Can use other apps such as Field Genius windows or android, at added cost.

I tested Reach RS2 single unit on local Ntrip, but found issues with my RTCM corrections from my nearest stations.?ÿ Some stations on the network based on WGS84 and others ITRF.?ÿ This was not an Emlid problem, as confirmed testing some South receivers with Surv -x and Field Genius apps.?ÿ

• If the ITRF coordinates are returned to WGS84 by the RTCM client then they can be interpreted as NZGD2000 correctly. However, if the stream user converts directly from ITRF to NZGD2000 then a ~ 0.7 m error may be introduced due to the divergence of the NZGD2000 and WGS84 datums.

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@kotuku4?ÿ

As it happens, I use cellular data to connect to the state DOTs VRS system in my suburban city. I have plenty of trouble getting a good enough connection (using either the city's VERIZON phone or my personal TMOBILE) to stay fixed. It's a real frustration. I do not find cellular to be a truly satisfactory solution, and I'm not in a remote location at all.?ÿ ?ÿ

@norman-oklahoma?ÿ

Agreed. We currently only use base and rover RTK with UHF radios.?ÿ

Have some watermain replacement projects that would have been ideal for Rover Ntrip for topo point collection, and as built surveys.

But I could not resolve positioning problems, later found to be the base station I was trying to use.?ÿ The network owner really needs to upgrade.

Still an option to set our own base and use an Ntrip caster, but I doubt we will bother.?ÿ

Hands down Emlid.

If you don't mind the differences, you can go even cheaper with Polaris, but the wiser choice would still be Emlid.

After all the advice you get, you will find yourself going back to the Emlid solution.

Emlid RS2

@timd1971?ÿ I chose Polaris since it uses my own cell phone (3g, 4g or 5g), has no internal parts other than a receiver, bluetooth and a flashchip, and the cost makes it disposable. It makes for a good second order network rover (1cm), all day static receiver and one-step Rinex3 conversion for OPUS.?ÿ And since it's Taiwanese, I can tell myself, 'it's not really Chinese'.

@oldpacer?ÿ

Let us know how it goes!!?ÿ I am quite sure you got the lowest price possible for multiband GNSS besides DIY. (i.e. Emlid M2 and the additional components to make it complete).

Is there a Rtn (real time network) available? If so, there are a bunch of javad users buying new GPS base stations. Me included. If you download the javad app, onto a cell phone, your cell phone can receive the corrections from the Rtn. And, it can produce a hotspot.(WiFi). Our old gps units (Triumph 2 units) will hook up to this WiFi, and you now have a functional cm grade unit. I saw one of these used ones sell on eBay for 1k.

There are a number of surveyors who upgraded to a 4 constellation base, but still have a T-2. I'll probably sell mine. After I'm sure my t3 is sound and happy. The t2 is a 2 constellation system, with part of other Galileo, and Bideu.

Of course, there are a number of ways you can solve this. GIS does not usually demand more than 1 meter accuracy.

If you have a local surveyor, who has javad gear, it's a possibility that he can help you.

GPS is neat stuff.

Nate