I am opening a discussion concerning the use of a satellite based source of RTK corrections. Specifically, Point Perfect. It is a pre pay subscription source of rtk corrections that comes from the satellites in much the same way the GPS signal comes. No internet is required in the field. No radio base either. I’m neither selling it or pushing it. Just wondering the level of desire for it. My initial thoughts is that if my dad can simply plug in one gps and it is automatically corrected then it would be worth the subscription. But want to know what the community thinks.
Ublox sales and tech please feel free to offer your advice and what you offer here. Let’s find out what the pros and cons are of this solution.
First question:
Can the F9P receive these corrections without the separate daughter board? Stickers on a new F9P says try PP for a month for free.
The free trial service is the Internet version of PP. The GPS receiver will need Internet access somehow. A 4G daughter card, WiFI, etc. The L-Band reception version requires a receiver daughter card. Ardusimple lists it for $143 but one has to contact them to order it.
Thanks for clarification on this. That makes sense.
If using through wifi is it similar to the typical ntrip mount point etc?
I know the L band there is an access code that changes every 28 days.
Also you need an antenna that will receive this band.
Through Wifi would be similar to using a service like rtk2go.
The encryption key changes every 2 months and needs to be provided to the F9P at every startup. This would require modifying AgIO to send the key.
The L-Band board can do an antenna pass through to the GPS so no extra antenna would be required. The antenna will need to be one that includes L6.
Does the F9P request the key? The AgIO can be changed easy enough to send a key. Does the user get updated keys automatic or would AgIO be able to send a GET request when it has internet. And if the intended use is without internet, can the user get the key from the satellite service?
Correct.
I have this working now and it’s pretty sweet. One RTK2B board plus the D9S and L-band compatible antenna. Took a bit of head scratching to work out the procedure as I was passed various manuals to read, but it’s actually pretty simple.
Happy to write up a full procedure for this.
I’m out in the field with a bunch of archaeologists testing it out and am getting an RTK fix in about a minute, then around 3CM precision (I believe, this is being tested).
The beauty of this system is that no base is required which means that half way through a job, you don’t lose RTK (NTRIP) if your neighbourhood suffers a loss of power. It also means that only one board plus antenna is required which saves the cost of a second board and antenna. No range limitations, no loss of precision over long distances, no base station security issues, no settling down (survey-in) delays, no radio base station fiddling.
Configure it once, fire it up and you’re working in a minute.
Is there a subscription cost?
Yes, there are various plans. I’m paying £30 per month for unlimited RTK because I am going to hammer it, but prices start at $0.25 per month.
https://portal.thingstream.io/pricing
If you consider the price of a simpleRTK2b plus antenna (£250 ish) then this is an excellent alternative.
This has now changed. It is possible to store two keys, 58 days.
There is a drawback with satellite based corrections. These corrections come from a geo-stationary satellite and if the fields are a bit far from the equator, the signal may well be lost from any limited view towards the Southern sky. Very different from the loss of GNSS satellite visibility where a hill in one direction does not matter much if other directions have reasonable visibility.
Pricing usually is not competitive at all with a private RTK base. I got a bit lost with the $0.25 per month plan, how useful is 500 messages per month per device?
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That’s interesting.
I’m in Northern England and the results are bang on so far. Took some points, went out the following day and verified them.
The pricing does confuse me to be honest, I’ll clarify this.
After months of fighting with the Point Perfect we found that for a point survey tool, this may be an alternative for some people. However, the key upload monthly or bimonthly is a deal breaker for our purposes. Having to install the key each f9p start is not practical.
To be fair, we are not using this for the AOG software. The software we are using is a Pi based gps logger. The key transfer may work well in windows. But for our uses inside a Pi network it is not useful at this point.
Perhaps others will have better results. We were able to use this through the GNSS master android app with some success.
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Just gave up on it, unfortunately.
If you ever have problems uploading the key to your MQTT client, then you need internet access to download said key. If you have internet access, you may as well just use NTRIP.