Check out this new system. Looks like the UAS and AG industry may start driving the cost of equipment down. RTK for $699 a piece.
https://reachrs.emlid.com/
There's another post about this today.
L1 unit limitations
Ah didn't realize it was only single freq.
People on the Reddit r/uavmapping forum are saying it's just as accurate at close range RTK as dual frequency. Is there any truth to this? I've never gotten good results from single frequency, even on wetland flags...
I agree...the big survey equipment companies have been ripping us off for years on these and other things. It's the same in the sUAS world. 95% of surveyors will get zero benefit out of buying a $75k Leica sUAS vs. a $5k DJI one.
tomchurch, post: 411728, member: 10174 wrote: People on the Reddit r/uavmapping forum are saying it's just as accurate at close range RTK as dual frequency. Is there any truth to this? I've never gotten good results from single frequency, even on wetland flags...
Just going off there specs the accuracy is nowhere near as good as dual frequency, regardless of range. And I would expect the accuracy to degrade as the range increases much more rapidly than dual frequency. Dual frequency allows ionospheric biases to be modeled much more accurately because the different frequencies are affected differently. This is only one of several reasons why L5 should be such a dramatic improvement once it is fully operational.
tomchurch, post: 411731, member: 10174 wrote: the big survey equipment companies have been ripping us off for years on these and other things
When you pay the big bucks for a high end receiver what you're really paying for is largely the R & D that went into developing it. When I worked for one of said "big equipment companies" we were told that they had to sell something like 10,000 receivers just to recoup the cost of developing a new model. Some of the companies selling low cost receivers don't have those costs, they're buying everything OEM and slapping it together in a factory in China or somewhere.
tomchurch, post: 411731, member: 10174 wrote: 95% of surveyors will get zero benefit out of buying a $75k Leica sUAS vs. a $5k DJI one.
Depends on what you're trying to do, although I agree that I'd never pay $75K for a rotary UAS.
I predict that the big players in this whole game will be the data collector and software
Nate The Surveyor, post: 411738, member: 291 wrote: I predict that the big players in this whole game will be the data collector and software
I agree, and this has a lot to do with why I'm so big on Trimble - Access is a fantastic piece of software, and Trimble's overall solutions are extremely powerful and solid.
Wouldn't some or a lot of the accuracy be related to antenna design and size on a UAV? As in much of the radio world, it is antenna that determines if anyone can hear you.
SHG
gschrock, post: 411729, member: 556 wrote: software defined receivers that use your smart phones processors are a reality as well.
Yep, in the amaturer radio world SDR is the big and upcoming thing, in fact, there are starting to be VHF/UHF radios that operate as a radio, an Android phone and fit in your pocket. Here is one that just released, not only radio, but a DMR digital radio, there is going to be vast changes in radio devices in the near future and at consumer prices.
SHG
I recall reading years ago that a significant chunk of a dual-frequency receiver's cost went towards licensing fees on patented algorithms or somesuch. Anyone know if that's still - or ever was - true?
Jim Frame, post: 411757, member: 10 wrote: I recall reading years ago that a significant chunk of a dual-frequency receiver's cost went towards licensing fees on patented algorithms or somesuch. Anyone know if that's still - or ever was - true?
I heard this as well, and that there are only 4 patents, this was around 2007 so there may be more patents now. It's been awhile but I think Ashtech had one which is now trimble, Leica had 2, and I forgot the other one, but it has to be Topcon.
My guess would be Trimble, NovAtel and probably Septentrio provide more OEM boards than any others, at least for the higher end gear, not sure who the predominant supplier of chipsets in consumer devices is? A good guess would be Broadcom...
Here is a GPS World link about some of what we are discussing.
SHG
Not to discount the future of low-cost precision GNSS, but I just read Gavin's article on the Trimble Catalyst software-defined receiver that runs on a smartphone. It requires a software subscription, which currently costs $350 per month for the high-precision version. At that rate you could pay for a Javad Triumph-LS in 3 years. So, we're not quite there yet on the low-cost part.
Shelby H. Griggs PLS, post: 411755, member: 335 wrote: Yep, in the amaturer radio world SDR is the big and upcoming thing, in fact, there are starting to be VHF/UHF radios that operate as a radio, an Android phone and fit in your pocket. Here is one that just released, not only radio, but a DMR digital radio, there is going to be vast changes in radio devices in the near future and at consumer prices.
SHG
Can you explain to a novice what I am looking at when I open your link? Is it just a cell phone combined with a programmable radio?
What capabilities does this add to a programmable radio...or is it the capabilities added to the cell phone that are significant?
Looks to me like they have not reached the production stage yet, otherwise they would have actual pictures rather than just models. Same goes for the Reach RS.
From the little bit that I've been able to see things from the other side, RTK and precision GNSS in general, is more than a collection of hardware (receiver boards, antennas, etc.). The processing engine is just as important. I was thinking about the question of L1 only RTK that Tom Church posed above. Most of us could give some experienced answer, but it would be based on experiences that are a decade or two old. Many advances have been made in atmospheric modeling and multipath mitigation, which would render many of these experiences out-dated.
I actually had a base I was testing that was accidentally only broadcasting L1 corrections for GPS and Glonass. At the rover, I was pushing all of the places I usually work (none of which fit the textbook suitable places for RTK). My performance was noticeably off, but I was still producing fairly well, so I didn't investigate the issue. That evening, I discovered my issue. I still wouldn't want to work with L1 only, but my point is that the rover's ability to process the data was significantly better than that of a few years ago. The difference, in my opinion, was the RTK engine.
How developed is the RTK engine firmware in a $700 receiver? I don't know, but I would suspect it isn't terribly robust and likely doesn't have a team of engineers perpetually improving it like the larger manufacturers. It's not just the software that you see (like the data collection) it's the software that you don't see that makes the real magic happen.
Others can speak to this question, but I wonder if the Chinese receivers with Trimble boards have the same firmware as their Trimble clad counterparts. I have it on good authority that the performance is equivalent, at least for some receivers, for Chinese made and Trimble made receivers, but I still wonder about the firmware.
I'm all for technological improvement and capitalist competition. We all win in that. Most of the individuals I deal with are not yet equipped to take an RTK system out of the box and start making it work without support, which costs money, either from the manufacturer or a dealer. I suspect that the $700 RTK will not be able to offer this support. I believe this was a huge barrier for the Chinese made receivers until they found some domestic dealers with very good reputations and support skills to ease those concerns.
Surveyors are a pretty conservative bunch. They typically don't jump on bandwagons, understandably having a strong preference for reliability. Lower cost is attractive to some, but most realize that if they spend a week trying to get something to work that they could have been billing out, the cost savings start to diminish quickly.
Just some random thoughts.
RFinder has released the radio/phone AFAIK. I have not seen one of these in person, but the idea is a single Android device has both a phone and a two way radio, this radio is specifically geared toward the Digital Mobile Radio (DMR) flavor of digital two way radios. There is getting to be quite the DMR repeater infrastructure on both commerical and amatuer sides, what this device brings is ease of use, via a database and built in GPS it will show you what repeater is close and set all the settings automatically. Many of the DMR repeaters are linked via internet, so you can actually talk to any other user anyplace, even other side of world if you are both on the same network, the key is keeping all the database data current, so this device makes that easier. This device is geared toward amatuer use so you couldn't use the radio part without an amatuer licnse nor could you use it for work unless you had a FCC business license AND it is Part 90 approved AND it is open to business frequencies. Most, if not all DMR commercial repeaters require paying a monthly fee to roam on the network. Here is one commercial offering in my area: http://www.daywireless.com/tower-services/trbowest.htm
A few other links about DMR and a video review of the RFinder device.
https://en.wikipedia.org/wiki/Digital_mobile_radio
http://www.livefromthehamshack.tv/2016/12/06/episode-70-rfinder-android-dmr-radio-review/
makerofmaps, post: 411721, member: 9079 wrote: Check out this new system. Looks like the UAS and AG industry may start driving the cost of equipment down. RTK for $699 a piece.
https://reachrs.emlid.com/
Did you look at the specs?
PPK HZ 10mm+1ppm, PPK VT 20mm+2ppm
RTK HZ 25mm+1ppm, RTK VT 50mm+2ppm
Did they change the plan to phase out L1?
The $350 a month option for SDF looks very tempting. Certainly for me as a GIS tool looking for decimeter level recording. This would have to tie in with a business model where there is three months in a year of GPS heavy work and 9 months of other activity that doesn't need a measuring device.
Buying a new GPS over 3 years is fine if you have the use for it, but that Javad Triumph LS will be out-dated after three years with all the developments taking place. Consider my Hiperlite, bought second hand 4 years ago, the dealer now laughs when I mention trade-in. The Hiperlite will do fine for when I need a higher precision, four or five times a year, but the regular tool will be something that fits in the car glove box and talks to my phone.
All depends where your market is.
Dave
