I have owned Leica, Trimble, Carlson and Topcon. The only brand I no longer have is Topcon. My Topcon would lock every where and it would lock quick. Problem was, too often the points were garbage. Got to where I didn't trust it. Meanwhile, most of my competitors use nothing but Topcon...that is, until they tried the BRx7. Now, several of them have switched to Carlson.
All of the builders and excavating companies we work for use topcon gnss (because of price). Some of the work I see out of them is bad. I always assumed it was user error, because these places are wide open, no canopy. Sometimes they build a pad that's 5 feet too short in depth for the house going on it.
I used to have a sokkia grx2 base and rover and I can't complain about it but I spent a lot more time trying to get good shots in a little bit of canopy. The Trimble r10 that replaced it was maybe slightly better and the r12i is a lot better and I have found some usefulness for the IMU from time to time.
I would think all the major brands newest models would be somewhat similar in canopy.
I've had firmware make a huge difference on the r10 I was using before my new r12i. It went from 11-12 satellites to around 20.
It also seemed to help the old sokkia grx2 as well.
I tried Carlson survPC demo on my old Panasonic fz-m1 tablet (windows 10 tablet like the one you're using) and it ran fine on it just the same as magnet field did.
I would base the purchase decision on the equipment and software "ecosystem" you are or want to work in.
I love our BRX7. I hated using Topcon GPS, but that was about 15 years ago so almost certainly have improved since then. Sokkia's small "bullet" receivers work well for the construction stake out firms in my area.
I'm looking for you guys' experience with these 2 GPS units. We currently have a Topcon VR on rent-to-own that we are considering purchasing. We have also considered purchasing a new Carlson BRX7 unit instead of the Topcon. The reason we have considered the Carlson over the Topcon is because it seems there claims of how well it performs in canopy are true based on a couple of local surveyors that have the BRX7 and getting signal in canopy is a game changer for sure. I know a surveyor that claims he hasn't used a total station in 2 years since having the Carlson unit. I know another surveyor that has 2 of the Carlson units and says that they perform well in any terrain at any time of year. Our Topcon sales rep claims that the new 5.5 firmware upgrade for the Topcon VR allows it to go head-to-head with the Carlson BRX7. What has your experience been? Has anyone seen both units first hand and if the Topcon performs just as well with the most up to date firmware? Thank you
So I have used the Topcon Hiper VR system via a base & rover RTK setup in moderate to heavy pine canopy here in NC as well as for machine control and staking via Topcon Pocket 3D. There were times that it really impressed me. Then there were times I'd get bogus shots and was pretty disappointed as it wasn't really tracking the constellations as advertised in my opinion. Great GNSS for grading/utility contractors - I work closely with one who spent quite a bit on two individual base/rover setups with the FC5000 tablets and software. but I kept hearing stories of how Trimble, Carlson and Javad were killing it in heavy canopy
I then demo'd a Trimble R12i twice on the VRS network here in NC. Super impressed and it did what everybody was claiming. But just the receiver alone was double what I paid for my BRX7. I ended up buying the BRX7 as I was just as impressed with it from a performance standpoint in the woods running on the local VRS network. And thus far I love it. Not perfect but it's leaps and bounds better than the GNSS units we had from 1-2 decades ago and it's making life easier for everyone. Plus Carlson allows you to do the GNSS analysis point averaging to verify shots
I use the Brx7's. I purchased them to replace a set of Topcon Hiper-lite+. I also use a Leica 1105 Robot. Since I purchased the Brx7's, the only thing I use the robot for is to tie in buildings after setting a network of reference spikes with my Brx7's, or to double check my local TBM's for a septic design. In that situation the robot saves me time there over the Brx7's. I always check the GPS reference spikes with the Leica and find the GPS locations agree spot-on in both horizontal and vertical. In a thick wooded situation I might expect 0.1-0.15 foot variation between the two.
I'm getting to the age (76) when I would not consider a project where I have to traverse with a Robot. To do that would change my day from an enjoyable walk through the woods, to a grueling repetitive grind with heavy equipment that, in the end, would be less accurate than the multi-frequency GPS.
As far as comparing brands of multi-frequency units, I would guess that since they all have access to the same constellations, they all have the same potential capability, with some variation on account of the individual programs use of the GNSS data received.
