Just to make it clear before I start I'm not a scientist, I'm not a doctor, I'm just an old beach bum. Now that's out of the way I'm certainly not going to tell you I'm smarter than you and you should listen to me. On the contrary take whatever I show you here as a guideline not a rule.

As I'm a simple man I like simple things and it's the same with a gps. I just want it to record raw data with doppler speed errors and talk to me....I get lonely on the water! I'm not interested in connecting cables, analysing noise, standing still and looking pretty. I want something that tells me how fast I'm going when I'm actually moving while I still can.

So I came up with the simple man's gps SIMANGPS or ROOGPS for my own version! No it's not April 1st, this is serious stuff and I'm not joking. Stop giggling over in the back corner Daffy.

What I'm going to show you is earth shattering and will forever change the speed time continuum when powered by a flux capacitor.......well not really as flux capacitors aren't available commercially yet other than at the Area 51 gift shop. Sorry I digress.

The latest generation of Android 10 phones tend to be sold with the capability to use 3 or 4 gps systems to give you a location. The cheapy $60 version I've been experimenting with has GPS, Glonass, Beidou and Galileo. What it also has is S.Acc errors, i.e. the speed accuracy of the doppler speed. Just what I've been looking for. It case this is major news to you it just shows you haven't been reading my previous posts (I told you about this in May 2020). For a bit more money you can get a fully waterproof phone so you won't need an aquapac to keep it dry. There are also dual frequency GPS phones on the market that are even more accurate.

You can use a neat little free app called GPSTest to view the data and record it if you want. Shows all the sats being used and the accuracy. play.google.com/store/apps/details?id=com.android.gpstest&hl=en_US&gl=US

For those of you with inquiring minds this probably isn't enough, you want to have all the GPS cake and analyse it too. So what you need is an app to record the raw data and download it. Sadly there isn't one however that's not the end of the story. Google in its great wisdom is happy to give you gratis a copy of Android Studio. So what you may ask! Well smartypants I'll let you in on a secret...it lets you write your own apps so you can record the data you want and do with it whatever you wish. developer.android.com/studio

I've been doing just that....aren't I a smart little bunny? Well not really as Studio makes it simple to do do. So I did. I have my own app to record the raw data and accuracy and automatically send it to me from the phone so I can analyse the file. Just working on it to tell me my speed while I'm moving. I've built my app to work with my phone and you can do the same if your heart so desires.

I reckon pretty much anyone can build the own SIMANGPS system using a cheap phone and their own app. It will never be officially recognised by any United Nations approved speed measuring secret society but it will keep you amused for hours. No need to post any pretty red and blue graphs to show how clever you are, just build your own and the speed will come.

Yours in Speed, Roo

JulienLe said..

Roo said..
There are also dual frequency GPS phones on the market that are even more accurate.

Don't go spending more money to specifically upgrade to a multi-frequency device, it's not interesting for our use-case.

It's just to offer people options Julien if they have lots of money and are technerds! The simple $60 Android 10 phone does the job nicely.

boardsurfr said..One might ask why you'd want to do that, since apps like WindsportTracker only require a download to record your speed, and even talk to you on the water if that's your thing. .........

I would think a 'Scientist' might ask the obvious question: "Does WindsportTracker record the error data?"

Of course, it might be able to de done with GPS-Logit as well, but that would have to be added in to the functionality by Manfred.

sailquik said..

JulienLe said..
Don't go spending more money to specifically upgrade to a multi-frequency device, it's not interesting for our use-case.

Good point. As I understand it, (not being a Scientist and all ) multi-frequency is a technology to enhance positional precision and may not help Doppler precision at all, but positional improvement could help with Alpha proximity circle accuracy.

I am still waiting for good accuracy dual or more GPS system.For my rural fencing requirements. Professional survey service in this rural setting may cost thousands of dollars to mark your property borders.I believe that properly designed system using existing GPS satellites could offer few cm accuracy.Remember that we may have unlimited time, not in hurry when marking position. Our device and software could spend as much time as needed to scroll over satellites, apply correction etc.
I we look at any smart phone description or promotion, hardly anybody mention gps positioning accuracy.But in near future we could possibly measure our board length or our height using gps without any other tools.

It will be interesting to know what is theoreticall upper accuracy for device that could combine reading of all satellites. In the nearest future even low flying SpaceX Starlink satellites may serve as super accurate source, if only equipped with right software.\

These require space and power. Which surveyors and farmers have plenty off but smartphones don't.

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."

JulienLe said..
These require space and power. Which surveyors and farmers have plenty off but smartphones don't.

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."

I hope that one day smartphones come with dual or triple system and we can get off the shelves ready survey tool.

Interestingly, he mentions at minute 13 that a slightly moving device has an easier time finding its footing compared to a stationary device.

boardsurfr said..

The only time that "error data" are every relevant is in the GPSTC challenge. You, who seems to be the person who has the final say about device approval, have made it clear that there is no chance that only devices with error data can be approved.

So as a GPSTC member, I ask:
1. Are you planning to approve logging with phone as long as the data have speed errors?
2. Will you have minimum requirements for actual accuracy, or will you approve phones with poor accuracy, like Roo's?
3. How will you deal with the vast variety of phones and GPS chips in the phones?
4. Will you allow any self-written phone recording software? If not, which criteria will you use to decide if logging software is acceptable?
5. Is there a formal, publicly available protocol for device approval that anyone interested in using a phone for GPSTC could use as a guideline?

I've got plenty of "$60" Android phone lying around that I'd love to use, as well as Android logging software I've written in the past. I never bothered trying to get anything approved, since I got the impression that actual accuracy would be not just very important for approval, but also needs to be shown without any doubt. But perhaps I misunderstood what you, as the apparent gatekeeper for GPTC device approval, said.

Wow! So unnecessarily aggressive!

It's clear that everything is not always as it 'seems' to you.

You have no idea of the accuracy of Roo's phone. You jumped to a conclusion based on a single image which you knew nothing about including where it came from, what phone it was and how it was being used. Very unscientific of you.

However,
Devices that demonstrate that they can reliably produce Doppler velocity data with closely comparable levels of accuracy and consistency as the better currently approved devices, and which can produce the Doppler error validation data can be approved for use in the GPSTC.

There is a formal document of guidelines and procedures that is available on request to those who wish to apply to have their device approved.

If you have any Android phones 'laying around' that you think could meet the requirements, go ahead and knock yourself out. As said, it would have to demonstrate comparable or better, accuracy and consistency, as the better currently approved devices, and produce Doppler error data of the same type as the currently approved devices, that backed this up.

But, if you don't think it can be clearly demonstrated that it is at least as good as your own currently approved home made ublox based device, you probably should save yourself the bother.

sailquik said..

Wow! So unnecessarily aggressive!

It's clear that everything is not always as it 'seems' to you.

Look who's talking. You jumped in on Roo's thread, even though the two of you could not have more different opinions about which GPS units should be allowed on GPSTC, to attack me. Your very next sentence is just another example of that.

sailquik said..
You have no idea of the accuracy of Roo's phone. You jumped to a conclusion based on a single image which you knew nothing about including where it came from, what phone it was and how it was being used. Very unscientific of you.

That's both false and aggressive. There are very good reasons to believe that phones in general, and $60 phones in particular, will have worse accuracy that devices like the Motion that have been specifically developed for high precision speed measurements. You only need to read the application note about GNSS antennas on the u-blox site. That information seems quite accurate, from what I have seen looking at both phones and the Sparkfun u-blox M9 GPS with a chip antenna.
If Roo's phone actually gives him speed accuracy estimates that are comparable to approved devices, it would be quite easy for him to post them.

sailquik said..
There is a formal document of guidelines and procedures that is available on request to those who wish to apply to have their device approved.

That's news to me. There was no such "formal document" when I tried to get prototype devices approved in 2018. So please send it to me, you have my email, and you know that I am currently working on a plug-and-play prototype.

Andrew, my thought about this thread was that it was having a dig at Peter, it's no wonder he jumped in.
I agree this should settle down, but it's certainly not all one sided.
We know Roo is a stirrer he's done it often enough to you in the past, now it seems it's Peter's turn to be targeted

Roo must be pissing himself laughing after he stirred the pot and stepped back to watch you two old keyboard warriors have a go at each other.

sailquik said..
There is a formal document of guidelines and procedures that is available on request to those who wish to apply to have their device approved.

I have requested that "formal document" here, but not received anything from you. You have my email.

Does such a document really exist? There was no such thing in May 2018, when I first tried to get a prototype approved. If there is a document that actually has been approved by the GPSTC advisory group, why do you not send it out as requested? Or better yet, post it here or on the GPSTC web site so anyone interested can see it?

boardsurfr said..

sailquik said..
So far we have just seen some results that suggest ONE particular 25Hz device MAY not be anymore accurate for Doppler speed @25Hz than if running it at lower Hz. Lets try not to get carried away trying to formulate a 'Grand Theory of Everything Doppler Accuracy' on such a limited sample.

Never mind that the "one particular device" is the only chip that has 25 Hz and error data that is commercially available. Never mind that Julien Le expressed multiple times that the M9 chip is mostly marketing hype, and choose to stay with the M8 for the Motions.

I used the neo-m9 in a Gyro, Ublox changed quite some stuff, especially under the cover.
But it is the same design as a 5, 6 or 7...

For my Gyro designs it is a very nice and welcome improvement.