Activity Feed › Discussion Forums › GNSS & Geodesy › HZ rates and fixes with RTK
- Posted by: @jonathan50
If the rover only received the even second corrections, no amount of ‘special way’ interpolation can provide new accurate data for the intervening time samples.
That would be true if all samples were independent.
But the true values at those times for which the rover computes estimates at 5 Hz are correlated, meaning that each one doesn’t tell you exactly what the next one will be, but the recent history tells you a value the next one is likely to be close to. So you can make a prediction that is not as good as the base would be able to get at 5 Hz, but much better than not using any values at all between 1-second times.
. - Posted by: @jonathan50
This is the same for what the salesman was describing. If the rover only received the even second corrections, no amount of ‘special way’ interpolation can provide new accurate data for the intervening time samples.
I think the system only needs “accurate enough” data to make effective use of the higher solution rate, something a well-designed extrapolation engine can likely provide. But I’m just an end-user who will never understand all the number-crunching that goes on in the box, so I can’t offer details.
I do know that when it comes to choosing an RTK system I’ll take the recommendation of a widely-respected and innovative GNSS system designer over that of a former GIS Image Analyst all day long.
- Posted by: @bill93
each one doesn’t tell you exactly what the next one will be, but the recent history tells you a value the next one is likely to be close to
That’s wrong Bill. There is no research paper that’s says you can predict the next value because the ambiguity parameters are not linear. The ambiguity parameters are in themselves located inside of statistical ellipses. It means there is no exact or correct value for each instance. As you yourself stated they are correlated but not linearly related. If what you say is true then someone would have made something akin to a logarithmic table to predict each 0.2 second of ambiguity resolved parameters.
- Posted by: @jim-frame
I do know that when it comes to choosing an RTK system I’ll take the recommendation of a widely-respected and innovative GNSS system designer over that of a former GIS Image Analyst all day long.
That’s ok Jim. Someone has to buy the stuff so they can keep their payroll going. It’s difficult for people that are only trained in 1 specific area of the geomatics field to grasp that geodesy does not only cover boundary work. So unless you have not used Google Earth ever in your work process previously, I will enlighten you that the images on Google Earth did not just appear out of nowhere on your laptop. There are GIS analysts that made those images zoom in with increasing detail using digital orthorectification software that are worth more than your house, car and several years’ income. All just to make sure that you won’t get lost while you drive to your nearest bar.
But hey, what do we know about GPS positions right?
- Posted by: @jim-frame
recommendation of a widely-respected and innovative GNSS system designer
and who voted for them to be a ‘widely respected and innovative GNSS system designer’ ?
must have been locked up in the GIS room when the survey was sent out.
- Posted by: @jonathan50
I guess we’ll just have to disagree until someone reveals the algorithm used for this extrapolation so we know for sure.
I’ve made my guess based on the ideas of correlated random process theory.
I’m not sure what you think their algorithm might be.
. - Posted by: @jonathan50
must have been locked up in the GIS room when the survey was sent out.
If you don’t know who Javad Ashjaee was, then I agree — you must have been locked away somewhere.
- Posted by: @jim-frame
If you don’t know who Javad Ashjaee was, then I agree — you must have been locked away somewhere.
How about you? Do you know who Javad was? If you did then you would have realized that Trimble & Topcon products were also made by Javad. So you see, Javad the company does not hold the title of the only ‘widely-respected and innovative GNSS system designer’. So if you believe Javad’s product to be superior then logic would also point to Trimble & Topcon to also have superior products since they were based on Javad’s work too.
So how’s the boundary work Jim? If you need any help on GIS or image rectification or satellite imagery processing, give me a heads up. Never too late to teach an old dog new tricks. Lol
Why do I have a feeling that you feel yourself to be superior to a GIS analyst? Am I correct? If you think the GIS tech is low compared to your boundary survey then better do more research my friend. You would be surprised to know that what we were using 20 years ago are just now being used in your surveying field. The drones that you are using to get aerial imagery were based on technology from the GIS field. The stitching of imagery to get a seamless coverage is based on the GIS field. The street navigation system in your car is based on the GIS field. The database that we had to create and edit held more rows than the number of shots from your largest topo survey.
Sometimes mocking others just reveals your insecurities and ignorance my friend and I am really sorry for you at your age to have such insecurities.
I do see a lot of insecurities on display. Verbose ones, at that.
- Posted by: @jim-frame
I do see a lot of insecurities on display. Verbose ones, at that.
Well it takes one to know one right?
- Posted by: @jonathan50
logic would also point to Trimble & Topcon to also have superior products since they were based on Javad’s work too.
Javad designed products for those companies a long time ago, but I don’t think recent ones.
As processing power has gotten more available and affordable, companies are refining algorithms, and Javad had long-accumulated knowledge of GNSS that enabled him to be a leading innovator in those refinements.
. - Posted by: @lurkerPosted by: @lurker
I believe your choke point is going to be ….
…. human capacity to comprehend.
Jonathan’s capacity seems to have blown out too.
At a surveying convention, a couple of years ago, I walked into the lobby, where about 10 persons were gathered. They all tried to get me interested in Trimble gear. I grinned, and said “it’s too late, I’ve already got Javad equipment, and I’m not interested”. They TOLD me that javad was going under, and when he did, that Trimble was going to buy up Javad, and they would have me then.
The general attitude of idest, and @jonathan50 is the same as that little Trimble gathering. They kick up dirt, (mostly imaginary dirt), and belittle, and behave in a most un professional manner. Are they related? I don’t know. But they seem that way to me.
It seems that this “group” does not want javad users to comment on a public forum, about their good experiences with Javad gear.
They throw rocks at the Javad LS, as being ugly, too square looking. (You are welcome to your opinion)
They say 5 Hz does nothing. (This is a lie)
They say RTPK does nothing. (This is a lie)
It’s a combined campaign to keep javad out of market share, push him under, and then buy his great technology.
I am a simple end user. I use javad surveying equipment. And I like it.
Last time I checked, this was USA. You can use whatever equipment you like. It seems that there is a little noisy group of people who want to push javad off the table. Then buy them. Just like they said they were going to do. This is in fact a business model. Google, and Facebook, and eBay seem to use it.
I think what this group is doing is un ethical. But, dangle the dollars, and it’s there. Trimble has apparently a large market share. And, they want to leverage this against all others.
As I said to that little group, in the lobby, at the 4h center, I’m not interested. I’ve got a Javad.
I don’t appreciate the folks who betray the whole industry, for their business model. Now you know some of what I think.
Nate
@nate-the-surveyor Nate, you have never been short on words. I have seen nothing unethical, maybe some barbs thrown.
Many of us have been around COGO, GIS, surveying software, CAD software, GPS, and now GNSS. Both on the development side of some and the user side of all. There was a time when cogo users bad mouthed CAD. Now, most if not all use CAD. There was and still is a time surveyors bash GIS, yet most use it every day in their work. COGO and CAD have merged into a desktop solution using GIS data as a background. All of these technologies are tools to help us do our job. I use them all. I am starting to use Lidar data and find the accuracy of most recent lidar good enough to use for most surface design except to tie to hard surfaces and underground stuff.
This thread started as a question of real time data rates from a base to a rover and do different rates better the end user. It has morphed into a good discussion about data. GIS data is gaining accuracy, in some cases survey grade accuracy.
Nobody has mentioned that you may be the only one tall enought to reach that box when it’s locked out at a 2M height. ????
Shawn had a Javad video where he demonstrated that three section collapsible pole, was that pole a snap-lock, or a compression lock pole? Didn’t hear that in the video. Cool as hell, though.
- Posted by: @nate-the-surveyor
Last time I checked, this was USA. You can use whatever equipment you like. It seems that there is a little noisy group of people who want to push javad off the table. Then buy them. Just like they said they were going to do. This is in fact a business model. Google, and Facebook, and eBay seem to use it.
I think what this group is doing is un ethical. But, dangle the dollars, and it’s there. Trimble has apparently a large market share. And, they want to leverage this against all others.
If Trimble really wanted to take out or take over Javad, it could easily have done so already. I used to be pretty heavily involved in Trimble-world as a trainer, beta tester and tech support, and Javad rarely came up in conversation. If it did, it was never in the context of being a threat, nor was there really any animosity toward Javad.
Those of us tech-nerds were always interested in what they were doing, and I always liked the offbeat ad campaigns. While there is some overlap, Trimble and Javad have slightly different approaches and different target markets within the geospatial world, so I don’t think that it’s fair to straight up compare them as if they were the same. Each one has a solid following and its own strengths and weaknesses.
I really don’t see the David-vs-Goliath or tech-monopoly analogies here. If anything the market is becoming more diverse compared to 20 years ago. I for one want it that way. Competition and innovation go hand in hand.
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman - Posted by: @nate-the-surveyor
They throw rocks at the Javad LS, as being ugly, too square looking. (You are welcome to your opinion)
They say 5 Hz does nothing. (This is a lie)
They say RTPK does nothing. (This is a lie)
It’s a combined campaign to keep javad out of market share, push him under, and then buy his great technology.
Let’s answer that one by one.
Yes, it’s ugly. When I buy anything, aesthetics is part of the consideration if others also offer the same functionality.
5Hz does nothing if as the salesman said, it’s extrapolated in a ‘special way’ to 1 hz.
RTPK does nothing, Static session needs to receive GNSS signals to process to positions. The problem in canopy is that signals DO NOT get through easily. If signals are able to get through easily then why the need for RTPK? RTK would have been sufficient to get several repeatable point coordinates. So if signals can’t get through then what is the RTPK going to use in its computation? Interpolated data? You are using the same batter to make both pancakes and waffles and you claim the waffles taste better than the pancakes.
You yourself said that your error circle was 0.19′ for a 2nd shot from a 0.05′ 1st shot. Let me remind you that when we talk of statistical error circles, the 0.19′ and 0.05′ values are for the radius not diameter. That is not repeatability for me. So where is the accuracy that you keep on saying you are getting from your gear. That’s worse than what Javad stated on their specs sheet for accuracy.
I am not laughing at Javad equipment. I am laughing at YOU because of your claims that don’t pass scrutiny based on your own results.
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