(483) ESP32 precision GPS receiver (incl. RTK-GPS Tutorial). How to earn money with it (DePIN)

[@AndreasSpiess]

Please order the "S" type of the antenna (all band). It is in the same link I provided.

[@AgOpenGPSMagyarorszag]

I think Ardusimple product pricing is quite competitive with those items you've linked

[@silverXnoise]

Crypto scams have had plenty of opportunities to justify themselves. They can’t. Avoid everything associated with them.

[@RWBHere]

Thanks Andreas. Very interesting, although I didn't quite grasp all of the nuances after listening once. More reading is required! The major weakness of GPS is the satellite constellation; a powerful CME, or a man-made EMP from an orbital nuclear explosion, can disable or damage numerous satellites. While it works though it's superb.

[@protektwar]

well the price went up 140E for S 110E for D

[@adenwellsmith6908]

There are some interesting distributive set ups. ADS-B monitoring leads to a business that makes money Blitzortung is another interesting one for citizen science. The general model of distributed sensors sending information to a central website, which merges and presents the data is interesting. It's an area where libraries should lower the cost considerably. RTK is clearly an area where this model works, particularly if costs can be lowered. A raspberry pi, a hat and an internet connection surely has to be the model.

[@mapgeek6]

Part of the reason that the US Military stopped degrading signals after the Gulf War is because scientists and land surveyors had already figured out how to get drastically improved results even with the degraded signals. But RTK is even better with non-degraded signals we all have access to today. I love this video!

[@AndreasSpiess]

You are right. Plus the competing systems were not degregated…

[@Sylvan_dB]

And another reason was the military was unable to supply enough special units and had to resort to commercial. Turning off the encryption on the lower bits allowed them to use commercial units with full functionality.

[@AndreasSpiess]

@@Sylvan_dB Indeed, this was mentioned in the book.

[@thisnthat3530]

Their reasoning was simple: Always obfuscate the signal and everyone ends up with a workaround rendering it useless. Don't obfuscate during peacetime and most receivers won't bother with extra tricks and will therefore be impacted when obfuscation is reinstated during war.

[@brookerobertson2951]

Gulf war ? It's only a game why did people go to war over it..

[@balee15]

I'm an engineer in Brazil, power electronics and lately developing circuits for use in the field in agriculture. The use of RTK was discussed the year before last, but it was not applied Brazil everything is very expensive and bureaucratic. It was used for planting with tractors. Today this idea was abandoned and they hired the company Kimble .. today my project consists of lora modules with the llc68.. where each device has 4 inputs, 4 isolated outputs, 1 GPS, and a Gateway with just 1 GPS module and covers 5km.. tractors, gates, motor pumps, sirens, everything done by this system...your videos are the best...congratulations

[@FullCircleTravis]

If I understand this correctly, you use lora mudules to broadcast, and then receive the signals with GPS to triangulate location of equipment?

[@balee15]

@@FullCircleTravis every device on tractors, for example, has a GPS. each device has its ID, a Gateway accesses all devices within a 5km area. The algorithm I wrote for lora radios They work like this: for example, tractor 3 has ID number 0x34. The user requests the position of tractor 3 (0x34) The Gateway acts as a broker, it requests data from 0x34, all devices receive it, but only ID 0X34 responds, and the complete package comes (ID, sensor status, actuator status and GPS)... The Gateway publishes this data to the broker and the user finds out

[@AndreasSpiess]

RTK is now widely used for precision farming. It seems you had a different use case

[@balee15]

@@FullCircleTravis The initial idea in 2021 would be to use RTK to map irrigation pivots. But due to the cost and the difficulty of development, it was an abandoned project. And the GPS modules purchased were used in tractors which send the position through a LorA network. Sorry for my English hehehe

[@balee15]

@@AndreasSpiess Unfortunately, I had to abandon it, who knows, maybe one day I will use it again.

[@Billcasiopost]

I too pay my respect to the engineers 40 years ago who devised this technology. Amazing

[@AndreasSpiess]

Indeed!

[@realulli]

Fun fact: the GNSS satellites constantly apply corrections to their timers, because they move fast enough and need to measure time precise enough that relativistic time dilation becomes relevant. 🙂

[@AndreasSpiess]

Thank you for the addition!

[@TymexComputing]

Gps also do that i think

[@Reach41]

@@TymexComputingCorrect. If not adjusted for relativity, GPS is way off.

[@realulli]

@@TymexComputing AFAIK, all of them do - they're all going at several km/s, so they all need to compensate for relativity. (at a guess, about 0.00003c)

[@janami-dharmam]

@@realulli even if they are not moving, they are affected by the gravitational field of the earth. A clock outside the earth's field with run slower. A different clock is needed for space application. The problem is currently managed by applying small corrections.

[@John_Ridley]

The first GPS receiver I used was a Sony Pyxis in 1992. It chewed through a pile of AA batteries in just a few hours and it took something like 10 minutes to lock on every time, and it couldn't deal with even a little bit of tree cover or heavier clouds. I now have a < $100 watch that can get a lock INSIDE a lot of the time in just a few seconds and can track for many hours on a tiny internal battery.

[@AndreasSpiess]

Indeed, we came very far…

[@mytech6779]

Your watch is continuously searching and has no accuracy standards to meet so it can take a half informed guess based on other hints. It doesn't actually aquire satelite locks that fast. I work with aviation GPS, and from a completely cold boot even with an external antenna on an open field they still take several minutes to aquire and verify enough satelites. After acquiring they update position multiple times per second, and with a quick power-down and reboot they retain some information and know they couldn't have been transported too far in the elapsed off time so they can reaquire much faster.

[@hydrocarbon82]

I built one with an arduino to clock the speeds of my RC boat a few years ago...maybe $10-15 in parts lol. The $5 ublox units are pretty amazing.

[@bdot02]

​@@mytech6779it's actually pretty interesting how phone and watch gps actually get a lock, whereas with a traditional GPS system you need to wait for the packet where the stations transmit location information (almanac), cell phones download this data over the internet, same typically is done over to the watch but that depends on the brand. What's crazy is that some gps chips will only work with a data connection and without it have no ability to get a gps lock.

[@jcugnoni]

Absolutelly great video. I looked at RTK 10years ago and it was just out of reach.. Now it seems nearly magically simple.. Amazing times.

[@AndreasSpiess]

Indeed, we live in amazing times!

[@schrodingersmechanic7622]

I've got one of those gps guided mowers, Luba 2. It is mind blowing how precise it is. It runs right up to my curb consistently. RTK is a gamechanger.

[@AndreasSpiess]

Thank you for sharing your experience!

[@golfshoe9321]

I have my RTK mounted in my air conditioned house attic which communicates with the LUBA. The attic has wood trusses. Is this an acceptable location? I would have to hire someone to mount on my roof. Would I gain more antenna views moving it?

[@AndreasSpiess]

@@golfshoe9321 I do not know, You have to try. Wood usually does not have a lot of attenuation (if no metal is inside).

[@Stefan-st]

I don’t know your model but normally this have cameras. Because GPS is not accurate enough with the small view of the sky under trees and next to buildings..

[@golfshoe9321]

@@Stefan-st My model does not have cameras. I am playing with GNSS planning software to time an optimal window for hight SN ratio.

[@jmr]

Knowing how GPS works only makes it seem more impossible. The precision is hard to comprehend.

[@AndreasSpiess]

I completely agree. BTW: My 1995 GPS still found its position after many years in a drawer...

[@jmr]

@@AndreasSpiess I remember how excited my uncle was when he got one around the same time. 😂

[@SimEon-jt3sr]

Just imagine image stitching but 3d... Once the image is built and verified and checked and updated over time, once that work is done... You are just checking points. The more points you get to check routinely the more confidence u have. Certain devices are verified very trustworthy or sent into the field to take readings to verify stuff. One the network is big enough, it works. Is that accurate at all?

[@jeffro.]

I remember getting my first GPS receiver in early 90s. I remember how disappointed I was to find out about the "ambiguities" the US Military put into it, and I sure was glad when they stopped! (I had " insider info" back then, lol). Still, it's so amazing that it works so well, and that it's used for so many things. As a ham operator, I use APRS regularly. I've been wanting to build an RTK for several years, just been waiting for the cost to come down a bit ... Thanks, Andreas! 🤪 👍 👌

[@tonysheerness2427]

When they put the technology into keys and wallets, one will never lose anything again.

[@chrisbryden8102]

Crazy! I’ve been into AG RTK for over 15 years for sure and probably have close to 500k into gear. Warms my heart to see you put together a base station for $300! I want to say my first station way back then was $50k!

[@AndreasSpiess]

This price drop was one of the reasons for this video. With the prices you mentioned this for sure was nothing for Makers like on this channel. And it seems that prices will fall even more in the future as there is some comptetition.

[@klauszinser]

@@AndreasSpiess , All: This one: simpleRTK2B - Basic Starter Kit is around 250 US$. They also used it in the Ardumover. What you have shown (also UBlox) seems to be better especially re communication. Correct me when wrong but your setup for the rover is (around 200-400 US$) and similar to the base station (300-600 US$). When there is somehow access to the Base Station only the rover is necessary. Just for a field or to follow a vehicle where the leading one has a driver or much better navigation (Range max 400m) and where there is just a cm accuracy but no link to the GPS necessary (includes precision farming and gardening, lawnmower..) I think I had seen different much cheaper technology. Any ideas? Dyson farming division where the produce a lot of strawberries etc inside, the must use s.th. different. And they say, they have an accuracy, when remembering correct below 10mm.

[@viktorakhmedov3442]

This is revolutionary. I'm a road surveyor/inspector in the US and use a Trimble RTK receiver with my state's free correction network over a 4G hotspot and it gives me awesome accuracy in the field all by myself but it cost $20k for the receiver (6 years ago) and when I opened it to replace a part, it was layer after layer of complicated circuit boards. To think it's been simplified this much is inspiring. Now if only I can find a way to do DIY tilt-compensation for the pole I'd mount it on.

[@AndreasSpiess]

These "layers over layers" are now in the chip, I assume. And therefore cheaper to produce. I agree, with this pricing it becomes attractive for DIY

[@pat_rick01]

Didn't know about the free state's services!

[@perstaffanlundgren]

Cant you simply mount two spirit levels 90 degrees of etchever to the pole and adjust them to center = pole plum ? Or is more complex to solve?

[@etmax1]

That's what one of those really cheap MEMS gyros can do for you.

[@allpointsthreesixty]

@viktorakhmedov3442 Trimble proprietary IMU tilt is based on electronic bubble technology that is not proprietary. Moreover, an electronic inclinometer is not so hard to execute. A little plumbob and a little protractor. Electronic totalstations have been doing it since the 80s for zenith angle compensation.

[@dcole7092]

I was a deputy test director for the first USA military gps application in the world back in 1989 : Rockwell Collins and TI manpack/vehicle test and Marine test. They were accurate to hit a 1/2 dollar size coin benchmark.

[@AndreasSpiess]

Incredible! Without a reference signal?

[@Native_love]

God bless our engineers! We owe our cellphones, computers, tv's, and all other 'smart' objects to their ingenious work! Respect!

[@AndreasSpiess]

Indeed, it is a valuable profession ;-)

[@robguyatt9602]

I agree with you to an extent but before the engineers are the scientists who do the base physics. Then engineers can design systems based on the science. I absolutely love being a designer and owe it all to the scientists that give me technology to work with.

[@amorpheuses1627]

As your subscribers we too want more. I would second the suggestion already made by a viewer: another video on base station setup. I was hoping this video would cover that but that would have made it too long. I know you weren't planning on doing one but I and I'm sure others would very greatly appreciate it. At any rate, thanks very much for the video - very interesting technology. All the Best!

[@AndreasSpiess]

We will see. The video performs much better than anticipated…

[@ste1l1]

@@AndreasSpiess I would love such a video. I've been looking into setting up my own RTK station and building my own auto-steer for my tractor setup on my farm. Commercial systems typically costs minimum 8-10k euros for the initial purchase of the system. On top of that a yearly subscription to RTK costs from €500 to €1000. From what I've been able to gather, I could probably build my own auto-steer system for €2000-€3000.

[@AndreasSpiess]

@@ste1l1 In the meantime, I started a project to build an autonomous rover (using Ardupilot). I hope it will be ready after summer break...

[@hypercube33]

Totally want this, I appreciate the links and options but its overwhelming how many there are to choose from - what did you end up picking, what worked well or didn't, are the cheaper options good enough etc. Thanks! Love your videos.

[@AndreasSpiess]

@@hypercube33 I used the UM-982, but the 980 will work too as a base. The info for the antenna is in front of the link.

[@pat_rick01]

Dear Andreas, I highly recommend you watch a beautiful English movie entitled "The Last Bus" which had my wife and I smiling and crying simultaneously at the ending. Also, I'm retired, disabled and poor as dirt but still marching forward on a project which will benefit grandly by a DIY indoor base station that makes it affordable enough. Thank you so much for addressing RTK the way that you have!

[@kingofcastlechaos]

I loved that movie, it was extremely well done.

[@AndreasSpiess]

Thank you for the tip. I will watch it!

[@sergiopagano599]

Very nice and informative video. Just an addition by a physicist. The engineers designing the gps system had to include the effect due to the fact that time flows differently on Earth surface with respect to satellite orbit, as explained by general relativity. The legend says that they at the beginning did not believe that it was necessary, so they introduced a software switch to activate/deactivate this correction, but then they had to use it in order to achieve the wanted precision.

[@AndreasSpiess]

Interesting detail! We engineers are always a little less to the detail than the physicists. But we accept reality (at least in a technical sense) ;-)

[@vogonjelc]

You have to account for speed and height of satellite.

[@GRBtutorials]

How would they not know? If you can calculate the correction, you can also calculate the error incurred by not using it.

[@AgOpenGPSMagyarorszag]

There's also centipede with quite good coverage in Western Europe. We use F9P receivers in our AgOpenGPS projects for both base (pi based) and rovers (tractors with Arduino )

[@AndreasSpiess]

Thanks for the info. It seems to be very good in France in Slovakia.

[@bEse11]

⁠@@AndreasSpiessFarmers in Hungary (not Slovakia) build these base stations by themselves. The cost of a station (~500€) is cheaper than one year of commercial correction subscription offered by tractor manufacturers / dealers for one tractor. Ater install, its free for all of the farmers' tractors within 20km radius :) We are running rtkBase (opensource) on a RaspberryPi4 + UbloxF9P, caster is Centipede

[@entropiemaximun]

​ @AndreasSpiess mainly France & Hungary! Nice open source project

[@OldCurmudgeon3DP]

Entrants in a GA Tech competition were using differential GPS for 1cm resolution some 25yrs ago. About time it became easy for everyone.

[@AndreasSpiess]

Indeed, technology advanced a lot!

[@newmonengineering]

I remember buying the google G1 with GPS maps. Iphone was released a year before, but it didn't have google maps. It was about 5 years after that apple finally had gps maps on their phone. I loved that I had maps at my finger tips, always knowing where I was on a map was a game changer. All the iphone people were jelous because they couldn't do that, and they already spent their money so the G1 being out the next year was a huge hit. Life changed during that time. Instead of guessing where you were, you knew exactly where you were and could easily get to any place you dreamed of going without trying to get out the atlas or large maps. Now everyone uses maps on their phone almost every day. Its probably one of the most used apps on a daily basis. Amazing how we are so dependant on it today, and yet before the G1, we had to basically guess about where we stood in relation to a map.

[@AndreasSpiess]

Thank you for telling your story! Very interesting.

[@gregorymccoy6797]

This is the best tech video I've seen all day. It is clear and information dense.

[@AndreasSpiess]

Thank you for your kind words and your support!

[@rickrock2525]

Video with high quality standards, fact based criticism where needed and professional content. I've seen so many "hobbyist"-youtubers tinkering in their videos, making low quality products, repeating well-known mistakes and reinventing things - just in lower quality.

[@AndreasSpiess]

Thank you! I try my best.

[@TimoNoko]

Original Garmin 1993 was funny. It did not work right in the southern hemisphere. I bicycled in Australia and it reported negative speeds and sun rising in the evening.

[@AndreasSpiess]

That is interesting! I had no chance to test mine in Australia...

[@confuseatronica]

hah I saw that setting on my old garmin gps and wasn't totally sure what it was for- i mean certainly the model wasn't so simple it would think people were upsidedown in the south. I guess it was..

[@alexjohnward]

If you bought one in Australia it didn't work right in the Northern Hemisphere!

[@mjgrebert]

AND it took ages to get a lock when starting up

[@alexjohnward]

@@mjgrebert They took 12-15 minutes to get the Almanac.

[@tin2001]

I bought my first GPS receiver - a little yellow Garnin handheld thing - because me and a friend were looking at the feasibility of using wifi and yagi antennas to link his place to mine back when internet speeds were still measured in kilobits per second. We ended up building it and using it for a couple of years. 20mbps connection between houses almost a kilometre apart was amazing at the time.

[@AndreasSpiess]

Indeed, today this became easier (and cheaper, too)... But it was fun back then.

[@MiniLuv-1984]

Your explanatory videos are stupendously useful Andreas. Thank you!

[@AndreasSpiess]

Glad you like them!

[@Milosz_Ostrow]

If I'm not mistaken, this technology was developed by a team at Stanford University, Palo Alto, California, in the United States. They tested it while flying around the area in a Piper Cherokee single-engine airplane. While doing so, they were vexed by random vertical position errors of 2-3 cm that they could not eliminate. Eventually, they discovered the error was due to the flexing of the airplane's wings in slightly turbulent air! The result of their work has made it possible for airliners to take off and land safely under zero visibility conditions, completely under 3-axis autopilot control, as long as there is a GPS base station or "pseudolite" present in a precisely known location at the airport.

[@AndreasSpiess]

AFAIK, aviation uses Differential GPS, not yet RTK (WAAS)

[@eclectictech]

I believe I attended a presentation at Oshkosh years ago that covered that work (if it's the same one). My understanding is that many airliners, particularly older aircraft like the 757/767, older 737s, and many others aren't using GPS because their navigation systems were certified so long ago and the costs for retrofitting a certified system into the older aircraft isn't deemed worthwhile... I think the 757/767 had some really good Inertial Navigation Systems. Aviation (at least certified VS experimental) is often far behind the rest of the world in application of new technology - for multiple reasons. The precision landing capabilities of many airliners is often due to a combination of two or more relatively older technologies: ILS, microwave altimeters, microwave guidance systems (CAT III ILS, I believe)

[@ericwilner1403]

Very interesting - it fills in some big gaps in my understanding of how RTK works. It's also potentially useful to me, as there are many potential applications for accurate positioning on a nerd's hobby farm.

[@AndreasSpiess]

Glad it was helpful! And enjoy your first project. We want to know about it!

[@damny0utoobe]

Thanks for mentioning a non greedy company for RTK. That helps me quite a bit.

[@AndreasSpiess]

Glad to help!

[@stevecrabb1]

Thank you for being the first one who explained how RTK really works. Unlike LORA devices I think there will be an explosion of RTK enabled devices and your average consumer will not want the hassle of base stations and positioning them with a good view of the sky. So definitely a good case for depin i think.

[@AndreasSpiess]

I also think it is more mainstream than LoRa. But we will see what the future offers…

[@619ota]

I’ve been running a GEODNET GNSS Station for little over 2 years…. DePIN is the future ❤

[@AndreasSpiess]

Thank you for sharing your experience!

[@originalmianos]

The developer of the most advanced GNSS chips and firmware, UBlox, are also more people with the Swiss accent

[@AndreasSpiess]

Yes, they are headquartered in Switzerland. Daniel Amman is one of the founders…

[@dchall8]

In the 1970s I was an engineer in the USAF working in the building next to the GPS development building. Every year we got to see briefing charts showing the GPS receivers on the back of a deuce and a half truck with the concept drawing showing that, one day, perhaps every Army platoon might have a guy with a GPS backpack, so they could take advantage of the technology and not just ships and airplanes.

[@AndreasSpiess]

Very interesting! It is increadible how far technology came in the last 50 years!

[@GlennHamblin]

Dude with the Swiss accent, you are awesome! Thanks so much for sharing this information with us! I love your content! ❤️

[@AndreasSpiess]

Glad you enjoy it! And thank you for commenting and following my channel for a long time!

[@serverguy2]

Part of the reception process is to determine the slight frequency difference of each satellite, as received, due to doppler shift. This helps spread the signals out a bit. If they truly were all on one frequency at one time, it really would be essentially impossible to make sense out of it. Even with the signal spreading and the frequent repitition of the code, it is still very difficult to receive. These tiny units do an amazing job for a small price. Thanks for the great, interesting video.

[@AndreasSpiess]

I was not aware that the doppler effect is necessary for the decoding. And I agree that these are wonderful small devices!

[@Sylvan_dB]

The progress in GPS receivers is amazing. My first modules were surplus motorola units which could track 8 satellites and that was amazing for the time. They used a lot of power and were closer to 100cm2. The real magic to me still, is in getting all that data by dealing with signals that are below the noise floor. 🤯

[@AndreasSpiess]

Indeed, many miracles have to happen to get a precise location!

[@carlettoburacco9235]

What I find bordering on science fiction are the new GPS/Altimeter/Compass modules for drones. (M10) In the size of a fingernail and a couple of grams they also include the antenna and have an accuracy of around one metre.(They are just a little slow in initial signal acquisition.) Considering that my first Garmin weighed like a brick and gave me 50 meters of accuracy in the middle of a flat plain, after about 10 minutes of waiting, only when all the planets were aligned looks like there was a "slight" evolution of technology.

[@AndreasSpiess]

Indeed. Fascinating!

[@mladenmatosevic4591]

Some 20 years ago I earned my postgraduate degree by proving that GPS corrections improve precision even if Selective Availability is disabled. To achieve that I used one of old u-blox receivers as reference station. You neederd to get raw range data. However, it wasn't full RTK.

[@AndreasSpiess]

Cool! You were very early with you work!

[@mazgch]

Hi Andreas, great video about a technolgy that fascinates me since more than 25years. Thanks for mentioning the HPG project and the various u-blox GNSS/GPS modules and services.

[@AndreasSpiess]

You are welcome. You know who started this journey ;-)

[@mazgch]

I spent half my life with GNSS technology, so maybe also for you it might not be the last time you discuss GNSS in your awesome channel!

[@NeroDefogger]

GPS is an EXTREMELY interesting technology that is very rarely talked about, and usually very vaguely, there are many great details very cool to know, people should study GPS way more

[@AndreasSpiess]

I agree!

[@mb106429]

they don't want too many people thinking about it too much

[@clintonherring]

I am SO going to build this, thank you! I have been looking for an rtk system for my drone and this allows me to build something and learn new things too!

[@AndreasSpiess]

Have fun!

[@JamesTrimble]

Same here! This will be very useful for my drone research.

[@mb106429]

yep, I want some bitcoins coming in from such a gadget.

[@clintonherring]

@mb106429 it won't be bitcoin, it will be onocoin or during beta, bono (beta-ono)

[@bears7777777]

The GPS knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation.

[@AndreasSpiess]

Good description!

[@Neumi]

There were people who figured this out ... and then there are people who think the world is flat.

[@AndreasSpiess]

Indeed, unbelievable!

[@MrRfaass]

@@AndreasSpiess The average IQ is 100, average means there are people with

[@flat-earther]

hi neumi, I think the earth is flat. I suggest watching _Level with Me (2023)_ by Hibbeler Productions to see evidence that space agencies are fraudulent.

[@flat-earther]

hi neumi, I think the earth is flat. I suggest watching _Level with Me (2023)_ by Hibbeler Productions to see evidence that space agencies are deceitful.

[@flat-earther]

hi neumi, I think the earth is flat. I suggest watching _Level with Me (2023)_ by Hibbeler Productions.

[@martink9785]

I use gps clocks for large area show synchronisation. Independent locations over 100 miles run perfectly in sync. Brilliant technology

[@AndreasSpiess]

Indeed. This would be hard without these satellites.

[@richard_wenner]

Yet another brilliant production Andreas! A perfect explanation without getting 'stuck in the weeds'. Watching this video has produced, in me, the same 'peak of joy' as in that moment when you first construct a digital coherer and resolve a hidden signal - that just 'pops up' magically out of the noise. Suitably invigorated, I can now return to yet another dead project, that could now work at a reasonable price - given your excellent research and guidance provided here. See you at the next WEF meeting in Davos - where we could share some of our massive gains?

[@AndreasSpiess]

Thank you! Indeed, these modern modulations are so different from what we knew before. Extracting a signal out of this "noise" seems impossible. Shurely is for conventional technology. I am not sure if I would go just to Davos if I get rich, BTW ;-)

[@richard_wenner]

@@AndreasSpiessI look back at the 'old days' of analog modulation and all of the problems involved. I feel sorry for all the folk who spent so much time trimming and aligning circuitry - when just mixing high speed digital circuits to/from RF circuits is such a breeze (using digital processing to do the 'heavy lifting' (as they say). The thing I really appreciate about your research is the time and effort you put into it and the practical outcomes. Too many times I have looked at these pages (and like Helium) think that they are a scam. Now you have taken the dive into these murky waters and given them your approval, I will follow as I too 'want more'! Thanks again. As for Davos - I thought that it was a little closer than Cardiff. Much love and good health to you. Richard

[@AndreasSpiess]

@@richard_wenner I know I never made it to Cardiff. You know, it is still on my bucket list. This year, we will go to the other end of the UK (Orkney). It was the wish of my wife. I hope this is enough proof of her existence. As you know, I would never choose such a destination myself! I would have chosen Cardiff ;-)

[@richard_wenner]

@@AndreasSpiess Why Orkney?

[@dragonfly-7]

Awesome compilation ! Actually I do have an application which requires high accuracy/precision as shown here. Now three years back I built my on system using an u-box evaluation board ZED-F9P plus a Raspberry Pi 3B+ incl. a 7" touch display as hardware and some 400 lines of Python code, PySimpleGUI and the GPSD daemon for software. The Python code is used to support GIS translation and to offer a GUI for a 7" touch screen. The high precision is achieved by using a NTRIP service (SAPOS in the given case). My device is now being used to support the localisation of "corner stones" ("Grenzstein" in gemran language) in both agriculture and forestry. When watching this video I had the idea for some improvements on my end ... 🤓 ... So: Andreas, thanks for the trigger !

[@AndreasSpiess]

Very good. Is this software open source?

[@dragonfly-7]

@@AndreasSpiess Not yet ... Actually my aim is to make it open source one day. But I'm not happy with its state at this time. I need to do a lot of refactoring. Actually it was my very 1st application I did in Python. So: Lots of quirks here and there which need to be straightened out before getting released on github. At least: making it open source is on my list ... 😄

[@darnok102]

If you combine rtk with imu sensor in rover (with eg kalman filter) you will receive even better results.

[@AndreasSpiess]

I can imagine. And I am sure this will be combined in modern warheads because of GPS jamming...

[@iniciusv1]

This type of solution gets me really excited! If commercial versions are expensive for those living in developed countries, imagine here in the third world where every dollar equals 8 local currencies. Perhaps it's a little beyond my abilities, but I would like to understand better. Thank you for sharing this.

[@allpointsthreesixty]

The short of it is a base station knows where it is, and runs on-the-fly position calcs on the SVs it sees every few seconds to derive a delta between otf position, and known position. It then sends corrections equal and opposite of the deltas to the rover. "I know I am at X, but OTF says I'm 1m S. Pseudorange correction for this moment=1m N."

[@nikjs]

if we could select a handful of people to make immortal so they can keep innovating and moving our civilization forward, i'd nominate this guy.

[@chuckb4375]

Great video Andreas - thanks! You obviously worked hard to find good economical solutions, and you have inspired me to start trying out RTK. I was also an early adopter with first unit being a GPS95XL, slightly older than your GPS90! I was fascinated enough by the technology to get the Tom Logsdon (AKA "father of GPS") book on it. Here in Oregon USA, our state government actually provides free (for the moment) RTCM3.x NTRIP/RTK access with good coverage, so no Onocoy revenue for me! I wish RTK module vendors would make their USB connection an integrated hub with 3 separate serial devices (one for RTK module configuration, one for NMEA output, one for RTCM input) to provide more flexibility to run separate apps (Google Earth Pro, GIS apps, etc.) without external mess attaching to other serial interfaces. The only solution I've seen so far is the uBlox EVK-F9P evaluation kit, which does this by adding a hub chip and two FTDI chips to the module PCB. Again, great video!

[@AndreasSpiess]

Maybe Ublox will also bring a 3 frequency chip. Then we can use theirs.

[@chuckb4375]

@@AndreasSpiess That would be great - some competition for things like the amazing Septentrio Mosaic-X5...

[@anthonycross901]

Yet again I learned a lot from this video of yours, Andreas. Super.

[@AndreasSpiess]

Glad to hear that!

[@vanhetgoor]

Yes! This was interesting. There is such a beauty in numbers and in mathematics. It is a true genius that thought of looking to the phase to get a higher resolution to the navigation. One day even this will be perfected again and again, the receiver can detect if it is standing upright or upside down by looking at the phase. But then it is necessary to know the exact polarisation of the satellite's antenna. Than the next improvement would be the checking of the phase in combination with the satellite's Doppler status, if one of the satellites is moving towards the receiver or from the receiver, then again another fine correction can be made to the timing. Then there is something with the steepness of the up-going flank of the sinus and the lesser steepness of the down-going flank, but I have no clue what we can do with it, yet! Life is so beautiful!

[@onocoy]

Let's unwrap this: * upright or upside down: This is not accurately possible with a single antenna RTK rover - but there are "heading" receivers which use two antennas and a short (1m or less) baseline between them, and can then determine orientation of this in space. A simple upright / upside down detection would best be done with a cheap MEMS accelerometer * antenna polarisation: The GNSS signals are RHCP polarization, and the antennas are designed to this [except for mobile phones, where antenna polarization for GPS is of little concern - usually linear polarized, at the expense of gain and multipath resistance] * phase versus doppler: It is the other way round: Doppler is measured by a GPS receiver already (as part of tracking the code and the frequency adjustments required to keep tracking it). Doppler is a relatively coarse (compared to carrier phase) measurement. GPS receivers determine the 3D velocity vector of the antenna out of doppler (and not by differencing consecutive positions as one may assume). Further, the phase measurement is actually reconstructed from doppler and can not be measured directly by a PLL. So only thanks to doppler measurements can the accurate carrier phase be "tracked" - by integrating "instantaneous" doppler measurements at a high rate. * "steepness of the up-going flank" Unclear to me what you mean by that

[@vanhetgoor]

@@onocoy Not even so long ago we could not even dream about measuring and pointing out a specific point at the phase. All of these innovations you spoke about are one by one wonderful achievements. At this moment in time it is almost impossible to make a prediction about what would be next.

[@wolpumba4099]

<a href="#" class="seekto" data-time="418">6:58</a> 1ns corresponds to an error of about 30cm, not 30m.

[@AndreasSpiess]

I knew that I get it wrong somewhere :-(

[@bengim]

At 6:17, too

[@bengim]

Also, at 9:25 (and further), you say the wave length for 1500 MHz is 20 cm (which is correct), but on the image, it’s drawn as a length of 2 wave periods, not 1 (ie 4pi, not 2pi).

[@Xsiondu]

Also you put your socks on backwards.

[@bengim]

@@Xsiondu it’s a technical discussion, about specific technical issues. Nothing personal. I fully respect Mr. Spiess. If you think your joke about the socks is appropriate here, you probably are in a wrong place.

[@ariafpv]

Such DePIN projects like you showed could be truly amazing to use in combination with open source software like Betaflight for drones and planes. They could really make this technology more widely available/affordable. A follow-up about small and efficient receivers for the "moving side" (drone, rover,...) would be really useful

[@AndreasSpiess]

I agree!

[@sebast6826]

Andreas, would you please stop filling my aliexpress shopping cart?

[@AndreasSpiess]

:-)) For me, this purchase was expensive, but worth the money. The time I invested in understanding it was even more "expensive".

[@sebast6826]

@@AndreasSpiess You are lowering these "understanding costs" for all of us.

[@dougcox835]

The fact that the satellites are so far away only improves the accuracy. All the receiver knows is time differences so the further away the better to see any differences in time from one satellite to another.

[@AndreasSpiess]

Good to know. Thanks.

[@chats5957]

It's not that new. I've been using centimetre accurate GNSS for 25 years. RTK, PPK and static observations. Trimble, NovAtel, Leica, Topcon etc. After looking at photos of GNSS base station installs for DePin projects, I would never use the service for anything that required precision. Many of the GNSS antenna installs I've seen are terrible: * Tall, unstabilised masts on rooftops that flap around in the wind. * Masts secured poorly with zipties * PVC pipes, or lengths of timber with a 5/8 thread stuck on top * People regularly adjusting, or moving their antenna will cause errors in connections broadcast. * People not installing their base antennas level, thinking that placing it on a slant will solve their 10 degree elevation mask issue with nearby trees. * People installing antennas on highrise buildings (thermal expansion and contraction from sun causes the building to move) * Installed on apartment balcony balustrade with >50% of sky blocked. Amateurs installing these bases have no concept on how GNSS systems work and cannot be trusted. I've installed many official GNSS base stations, and there are strict requirements for how they are established. Deep concrete base in stable ground. Calibrated and certified antenna. Several days of observations to establish base coordinates etc. Anyone using GNSS for commercial use would no use DePin network corrections. We spend $20k to $50k+ on our survey grade GNSS receivers and generally use our own base station setup over a known coordinated point and broadcast corrections over UFH, VHF or LoRa. These DePin GNSS networks will never get a foothold in the GNSS correction market. The only users will be hobbyists. I see founders of these projects claiming that agriculture will be a big market. That's not true either. Machine guidance systems generally come with a GNSS base to install at the farm. One base can transmit corrections to all farm equipment over radio. No need to pay a DePin project for corrections when you can supply your own for free.

[@AndreasSpiess]

Thank you for sharing your knowledge. I am no specialist in this matter. So we will see how and if such networks will evolve. For my part, at least I avoided the mistakes you mentioned ;-) And it took a while till my antenna was validated by Onicoy. I assume they try to do some tests about the facts you describe in your comment. Still, for a noob like me it was mind-boggling to see the accuracy and understand at least a bit how it is made.

[@chats5957]

​@@AndreasSpiess It's great that people are learning about precise GNSS as a hobby, as you mentioned, but as soon as startups start aiming their products at the crypto crowd, the network quality deteriorates. 99% of helium hotspot owners are never going to use helium LoRa devices, they're just in it for the money. Same goes for GeoDNET, ONOCOY etc. people are drawn to the $ instead of the tech, which isn't sustainable long term. Going forward, GNSS corrections will be required for many applications like ADAS etc, and government bodies will broadcast corrections over the internet, NB-IoT, LTE-M etc. free of charge. It's already happening in Australia. Nearly every GeoDNET base station in Australia is a government run base station (Geoscience Australia), and public access is free. Base stations don't need to be spaced at 20km intervals. Using surrounding base stations, the ionosphere can be modelled and virtual base stations established anywhere inbetween. That way GNSS bases can be spaced at 100+km intervals. Another way to receive RTK corrections is via satellite. Trimble RTX is one example. Centimetre accurate positioning without a local base or internet/radio connection. It's great to see that affordable RTK GNSS receivers are now available, and accessible.

[@onocoy]

Sure, what you are describing is highest-end RTK networks which can deliver mm-accuracy, as is required in surveying use cases, and a sub-1000$ equipment installed by a broad community can not deliver that. However, for many use cases, 1-2cm accuracy is sufficient. And things like long antenna masts that move in the wind, or antennas moved can be identified by QA through processing the inbound data

[@rspencer972]

Great points both of you, for what use cases would 1-2cm accuracy be sufficient ? I figure activities like geological surveys for gas, oil and construction industries right?

[@MichaelWoodrum]

In Ohio it's crazy easy to get access to the states correction system and link to base stations to allow much better collection of data points. I used it years ago to map my property for photogrammetric scans. The base station was $900 and adding more to triangulate was at least $400. Building these would be much better for this purpose now. Thanks for the info

[@AndreasSpiess]

So you are lucky that you do not need a base station anymore!

[@poisonouswhisper]

Could you do a more indepth video to follow to build such a base station and rover?

[@AndreasSpiess]

So far I have no such plans. But you never know…

[@klassichd10]

Thank you for your effort and sharing RTK knowledge. Keep us informed, please. RTK has huge impact on ariculture and so also on the production of food. Precise farming optimizes the amount of seeds and fertilizers etc.

[@AndreasSpiess]

You are welcome! I saw some examples in agriculture, and they are very promising. We will see if these new possibilities will change other industries the same as Google maps changed my way of driving ;-)

[@saxpert]

Sehr interessant. Du kannst mal auf den Cheisacher wandern, da steht neben der Sternwarte auch ein Mast einer Bodenstation für Vermessung.

[@AndreasSpiess]

Du bist ein guter Beobachter. Ich vermute, ich werde ab diesem Video auch welche sehen ;-) Es muss ja einige geben.

[@saxpert]

@@AndreasSpiess Die Bodensender sind glaube ich auch in der swiss geo admin map in einem Layer angegeben. Es ist eine sehr schöne Ecke dort mit dem Turm als Highlight ;-)

[@AndreasSpiess]

@@saxpert Ich hab ihn gefunden. Ersteht neben der Sternwarte shop.swipos.ch/Map/SensorMap.aspx

[@saxpert]

@@AndreasSpiess Sehr gut. Die Schweizer sind da einfach top wenn es um offene Daten und Kartierung geht.

[@TymexComputing]

Yes please tell it to us! Each year your english becomes more precise, just as public GPS services ;)

[@AndreasSpiess]

That's the plan! Thank you.

[@spicybaguette7706]

I'm curious if it would be viable to transmit RTK correction data over Lora. That way you don't need a power-hungry mobile connection on a remote device. Also, how often does the correction signal need to be transmitted for good accuracy?

[@AndreasSpiess]

I am sure it can be done (and maybe is already done). But only by a direct connection (not LoRaWAN)

[@onocoy]

GPS RTK data is latency critical. The data shouldn't have a latency larger than a few seconds from the RTK base until it reaches the RTK rover. Also, it is a continuous stream of ~1kB/s. Not sure whether Lora could fulfill both requirements

[@John_Ridley]

Another good book on the subject is "Pinpoint: How GPS is Changing Technology, Culture, and Our Minds"

[@AndreasSpiess]

Thank you for the tip!

[@TerraMagnus]

This kind of video should come with a blockchain crypto bro warning 😂

[@nyeleskettes]

10-15 years ago we played around with M8N and M6N neo modules with custom fw and settings + RTKLib. Back then the lesson learned was: use a good antenna. Till today I have doubts to invent into F9P based receiver because of multipath fading you really need a good GPS anteanna that performes on L1 L2 bands and is also capable of receiving well Gallileo and GLONASS satellites. The more SATs the better. The more bands the better. A really usable antenna (i mean on ground and heavily obstructed area like trees and buildings) costs 1000-2000$ The receivers got relatively cheap, but antennas are still beyond the hobbyist price range.

[@AndreasSpiess]

The receiver and antenna I use are capable to receive all kinds of satellites on L1,L2, and L5. As you write, this seems to be important.

[@john999]

Finally, a correct explanation of GPS. How often did I heared "triangulation" instead of "trilateration" (/ multilateration)

[@AndreasSpiess]

I am glad I got it right. I am an electronics, not a civil enginner ;-)

[@Joao46Andrade]

Hello Andreas. I don't comment a lot but I've followed your videos on and off since 2016. I was pleasantly surprised by seeing the subject of my Masters Thesis in one of your videos, and I wanted to thank you for doing the subject justice (it's been 8 years since I worked with RTK and I still can't fully comprehend the dark magic behind it). Cheers from Portugal!

[@AndreasSpiess]

So you were pretty fast in adopting this technology! Indeed, it is complex.

[@Joao46Andrade]

@@AndreasSpiess In the mainstream, yes! It's seen a lot of increase in popularity since, due to the availability of cheap GPS receivers that offer carrier phase measurements, which is always satisfying to see.

[@niyaziugur]

When you make the Helium-hate video several years ago, I posted a comment to it. I said that the bussiness idea is so good but in reality even if the beginning of the implementation of the idea welcomes some more doors to be open. Thanks for your videos

[@tonysheerness2427]

I take my hat of to you, You explained that very well in English and English is not your first language. I hope you make money as you deserve to.

[@AndreasSpiess]

Thank you for your kind words!

[@DigitalArtisan77]

That’s excellent news for competing with the major players such as with drones and DJI for example, whom have held monopoly until now.

[@AndreasSpiess]

Their bigger drones already use RTK…

[@DigitalArtisan77]

@@AndreasSpiess Sorry if I wasn’t clear. My point was, we as amateurs and enthusiasts are now able to create the same with a home build, something until now unattainable without firstly paying large sums to a major manufacturer and secondly operating that expensive closed system without the ability to learn something from it.

[@fgregerfeaxcwfeffece]

Seems promising. WIth how much cheaper this is compared to buying one it doesn't really matter if it ever makes money via DePIN. But I think that's plausible if the network is big enough to be considered a real alternative to the more expensive services. even if it just lowers their price.

[@AndreasSpiess]

For me, a cheaper price reduced the risk to start. To justify 700 dollars with my wife is much more difficurt than 300 ;-)

[@joetkeshub]

GORGEOUS! GENIUS! and so awesome! Thank you so much Andreas for your clear explanations and pedagogy. Great experiment with practical demonstration.

[@AndreasSpiess]

Glad you liked it!

[@HillTreks]

Fascinating. Thanks for taking so much time to explain how GPS works.

[@AndreasSpiess]

My pleasure!

[@cookinsteve9281]

Hope you’re doing well Andreas. Going from studying your videos to working in industry has certainly dampened my passion, but thank you for everything you do. It’s great to be reminded of why I do this to myself 😃

[@AndreasSpiess]

You are welcome. I hope you still find time for your passion…

[@dachoeks3]

Glad you are getting into rtk! In the USA we have free rtk correction service through transportation department.

[@AndreasSpiess]

Cool. Everywhere in the US?

[@dachoeks3]

@@AndreasSpiessyes.

[@billosland672]

@@dachoeks3How do you get access to local correction or base station? I looked up rtk 2 go and the closest station on their map shows about 100 km away!

[@AndreasSpiess]

@@billosland672 So you have to build your own 😞

[@bazoo513]

Extremely interesting. Of course, the fully detailed explanation would take a pretty long series of videos. Going over to your playlists... Thanks!

[@AndreasSpiess]

There is a whole lecture available on KZbin. But you have to invest a bit more time for that. For sure very interesting as a next step.

[@PassiveCryptoMining]

It's always interesting to see the crossover between experts in the industry and the stuff that I do which is focusing on DePin I can't post the link but my channel has videos on two projects that are adding quite well from this technology

[@AndreasSpiess]

I am not yet convinced, but DePINs with a business case have a better chance of surviving.

[@PassiveCryptoMining]

@@AndreasSpiess Geodnet is a project that is really growing in this space ( I made $7,000 from earning GEOD tokens, made a video about it too)

[@geromiuiboxz765]

🇨🇱 Ich wohne in Chile, und spreche deutsch 🇩🇪🙂 All I must say, your video was not only useful, it vas VERY useful, and not only interesting, it was VERY interesting ‼️ Vielen Dank, für dieses TOP Video 👍👌. Saludos de 🇨🇱

[@AndreasSpiess]

Vielen Dank für deine netten Worte!

[@johnlaurencepoole6408]

Thank you. I have anxiously awaited this episode since you hinted you would explore this topic.

[@AndreasSpiess]

It took way more time…

[@RideGasGas]

Speaking of Swiss accents, I just returned from Geneva where I was attending the ITU WP4A meeting. Always enjoy my visits there. Next trip in October :)

[@AndreasSpiess]

Indeed, our accents are similar because we both speek a kind of German as a first language.

[@arturmichnik3889]

God bless you Mister Swissman for such a fantastic quality feed for our curious minds. Not so strange, as its been made out of genuine passion. Respect. We owe you, Sir.

[@AndreasSpiess]

Thank you for your kind words!

[@DavidPritt-xh7qq]

I purchased a very large, and expensive, Magellan GPS unit for my boat in 1991, the consolation still had gaps in coverage and of course SA, but compared with Decca it was a revelation, had 20 waypoints, and I think you could store about 5 routes. Big screen do you could see the x-track error easily as you went along the route. But the basics are the same as my B&G Zeus system on my current boat, so I, too, am in awe of the sngineers behind GNSS.

[@AndreasSpiess]

Thank you for sharing this story. Indeed, for boats the initial precision was ok, too. Like planes, they do not use roads ;-)

[@dandan-gf4jk]

Haven't been here for some time but you've caught my attention with this video. Glad to see you're doing well Mr Andreas

[@AndreasSpiess]

Indeed, I am still healthy and curious. Thanks for visiting.

[@dr_jaymz]

We used differential GPS 20 years ago when surveying archaeological sites. It would give reasonable positioning down to about half a metre. If you want to know where that kind of precision becomes important, aircraft conduct gps approaches these days to align with a runway they cannot see because of weather. These are increasing and the older ils are decreasing because there is no cost involved to airports because no kit is required.

[@AndreasSpiess]

Indeed, DGPS and WAAS is used since a long time. Both use the modulation signal and not the phase.

[@alexl.3965]

Grazie per aver messo a disposizione le tue conoscenze. Molto interessante. Complimenti....

[@AndreasSpiess]

You are welcome!

[@TheLomsor]

I've been looking at this topic a while ago and couldn't find anything of use to make it work. Thanks for this Andreas!

[@AndreasSpiess]

Happy to help!

[@evlo8059]

Finally you solved my ultimate most wasteful over the top way to position how much the gete is open - RTK was the answer. So from boring rotary encoders on the wings we can go to hklink radar, which one might still consider sane way of doing it, it can at least detects objects in the gate wings etc. (in theory), but this, this makes no sense at all. So obviously i'm going to attempt getting precise gate wing positions this way now.

[@AndreasSpiess]

Probably a bit more expensive than a rotary encoder…

[@ohmicronD]

Excellent video and explanation. FYI, I believe the statement at <a href="#" class="seekto" data-time="418">6:58</a> should be 1 ns is 30cm not meters. Thanks!

[@AndreasSpiess]

You are right. My mistake.

[@ToeCutter454]

a lot of those "inaccuracies" are due to using less satellites to calculate position, most commercial devices will only stream data from 3 or 4 satellites because that's all that's needed for navigation in places where there's lots of signs and landmarks to find where you're going. the more satellites you can stream from the more accurate your resolution.

[@AndreasSpiess]

More satellites are always good. But this fact does not replace the need for RTK for high precision.

[@onocoy]

The number of satellites today is usually not a problem. Any modern receiver supports all constellations (GPS, Glonass, Galileo, Beidou) and have ~40+ Satellites in an open-sky view environment, even the ones in mobile phones doe multiple constellations (and in some models even on L1 and L5) In outdoor open sky environments, the accuracy is limited by Orbit/Clock/Atmospheric errors and that is what RTK can compensate for In urban environments, accuracy is degraded due to Multipath, so RTK works best in areas without reflective surfaces

[@dataplatter]

I use a homemade RTK pair to determine lake surface level. Using least squares regression over 6 hours it’s typically within 2mm of the survey markers, pretty much the meniscus.

[@AndreasSpiess]

Increadible! Thank you for sharing your experience.

[@Milosz_Ostrow]

While watching the video, I was thinking along the same lines. Instead of hiring a professional land surveyor at great expense, I would be possible for a reasonably knowledgeable person to use the technology to locate property boundary lines with comparable accuracy.

[@coffeegonewrong]

A lot of this sounds like just good customer care. - ensure there aren’t extra needs - avoid surprises by setting expectations up front

[@AndreasSpiess]

I do not understand the relation of your comment with the content of the video :-(

[@dronetoulouse]

Spent many many on the topic. Best explanation I saw.

[@AndreasSpiess]

Thank you!

[@TillmanZ]

Top Video Andreas! Mir war nicht klar, dass RTK inzwischen auf Rover Seite für nur noch „ESP32“ zu realisieren ist! 👍🏻😀

[@AndreasSpiess]

Viele nehmen offenbar auch Raspberries. Aber einen Rover habe ich noch nicht selbst gebaut. Hatte ja ein cooles board ;-) Vielen Dank für die Spende.

[@Master_of_Chess_Shorts]

super nice summary of the key concepts of GNSS perhaps some additional explanations on constellations of which GPS is a special case and geometry for geometric dilution of precision, how alignment of satellites plays a role in getting final accuracy. I remember how in Europe it was best to use a combination of satellites from different constellations (Glonass, Galileo, Beydou, GPS) and consider an angle greater than 14 degrees from the horizon before integrating their values in our calculations. We also used LORA to transmit from base to rover and vice-versa as wifi in the field could get expensive fast. We would probably use 5G today although network credentials checking from tower to tower is a precision hindrance adding delays. LORA did a great job. Thanks again for the update on a topic I miss in my current functions.

[@AndreasSpiess]

Newer receivers like the one I used "see" more than 20 satellites. So the constellation seems to be fo less importance than when there only was GPS. LoRa is for sure a good possibility to connect the rover and the base.

[@Master_of_Chess_Shorts]

@@AndreasSpiess 3 or 4 GPS are usable at any given time and I doubt your receiver sees 20 GPS satellites, it is already using multi constellations...

[@paulchamberlain7942]

Just the other day I noticed an automated line painting machine marking out a football field in a recreation park. I saw it had GPS receiver dome but the straight lines were too precise for civilian GPS. In fact on civilian precision there should have been no straight lines at all. I had to guy and ask the guy responsible for it if it had military grade GPS system. He replied that it was all managed by some company in Denmark. I figured had to be military but after seeing this then perhaps not. For a moment I thought about trying to rob the GPS off it, but quickly realised I and it would be found very quickly and decided against it. After seeing your video I realise this technology is accessible legally. I guess civilians can now guide drones accurately to their targets, ooops i mean destinations, with high precision too now. Delicious.

[@AndreasSpiess]

I am pretty sure, too that this robot uses RTK.

[@kiwirosethistles]

Nice video. However the true science of positioning is understanding coordinate reference frames, transformation parameters and datum’s. The earth crust is moving at different velocity and direction across the globe, while relative positioning solutions (RTK) account for this locally it is critical to understand these movements, particularly when you get to cm level positioning accuracy. The absolute accuracy of RTK is only as good as the coordination of the base station. Garbage in = garbage out.

[@AndreasSpiess]

I agree. Try to put all of this in a 20 minutes video ;-)

Real Time Kinematic (RTK) is/was either a trademark and/or a marketing term of Trimble Navigation Ltd. The difference between it and dGPS is/was corrections while the receiver was in motion, while dGPS required both the base and receiver to be stationary. 1cm horizontal precision and 1m vertical precision was available to professional users in the year 2000 (SA on or off).

[@AndreasSpiess]

Thank you for the additional information!

[@fredsteinhauser]

Great video, augmented GNSS in a nutshell! I believe an RTK base station should be in every major electrical (air insulated) substation. Creative asset managers with fantasy would imagine what they could get out of this. If it works with lawn mowers, it will work with any other robot. Even the costs of commercial base stations would be justified in this case. Of course, GNSS are vulnerable to being disturbed (as mentioned in the video), but there are ways to at least detect this. E.g., Galileo also offers message authentication. At <a href="#" class="seekto" data-time="412">06:52</a> you probably wanted to say: "a difference of 1 nanosecond means already an error of 30 centimeters". In imperial units, the speed of light is easy to memorize: one foot per ns.

[@AndreasSpiess]

Indeed, I made a mistake in this calculation!

[@emmanuelr6698]

Very nice, thank you for sharing this project. It's still amazing that we can now achieve nanosecond precision with some COTs !

[@AndreasSpiess]

I agree.

[@gafaff]

I am fortunate to have access to free correction data from the government's AUSCORS service in Australia, with the nearest station about 15km away. That said, given accuracy is a function of the distance from the base station (baseline), I'm tempted to set up my own local base station.

[@AndreasSpiess]

You are lucky! I geared that inside the 20 km, the degradation is not big.

[@ifell3]

You are such a geek I love it 😁. With things like this and meshtastic I can see it might be very handy in disasters.

[@AndreasSpiess]

Indeed, I am fascinated by technology!