What RTCM3.x messages are people using?

As the titile says. I’m not 100% sure of the differences in some of the messages. Mine are WEBBPARTNERS on rtk2go.


I think these were the default ones on the base setup configuration file (except 1008).

I see quite a few use the MSM7 type messages rather than 4.

I also can’t work out how to alter the individual message rates, if possible on an F9P?

Message rates are set first by setting the overall message rate (200ms for 5Hz, 100ms for 10Hz) under CFG_RATES, and then individual messages can be set as multiples of that under CFG_MSG. For example if your base rate was 100ms, then if you set the specific RTCMv3 message type to “1” that would send every 100 ms, or 10 Hz. If you set it to 2, that would be 5Hz (200 ms). Set it to 10, and that would be 1Hz. Some messages are not required very often, like 1005, 1008, and 1230. Could set those to 100 which would be every 10 seconds.

I use MSM7 messages, which seem to work with my Trimble receivers. Not totally sure the difference over MSM4. 1Hz is enough for the MSM messages, 10Hz is enough for the antenna messages.


Ah right!! Thank you. I was mistakenly thinking the 0 or 1 for messages was just a Boolean on off thing. Looked everywhere for an individual rate for messages!

Is there any point in the base rate being say 5Hz if the messages are going out at 1Hz and 0.1Hz?
Does it improve accuracy?

I don’t know, honestly! The usual rate I’ve seen in the wild is 1Hz.

I left the default RTCM parameters on my piksi at 1htz

Yes, that’s what I’ve seen. I don’t understand the hardware anywhere near enough to know whether a 10Hz receiver rate would have a positive effect on the 1Hz output message quality.

I have seen one Ardusimple page that mentions accuracy improvement with MSM7 over MSM4. Obviously with a heavier data payload.

Pretty sure the MSM observations need to be at least 1 Hz for any sort of accuracy. I’ve seen fixes last for up to 30 seconds without an RTCM message, but I’m sure accuracy drops off precipitously.

The antenna messages (1005, 1006, 1008), and the 1230 can be less frequent. I’ve seen some commercial networks that broadcast them at 10 hz. These messages never change anyway, as they are describing characteristics and attributes of the base station, like it’s position, which never changes. Probably the rover just needs to see them once is all.

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With an F9P as Base 1230 will be an empty message. The bias corrections are already done before it creates rtcm data, so you don’t need them.

I’ve set the board to 1HZ, and use RTKLIB in between the F9P and Snip Caster.
I send the following string:


In this case I also send out legacy data for older systems like my neighbours AgLeader Paradyme


Are there some who have an overview of what rtcm messages should be sent to the different brands of recipients, thought it might be smart with a table where the different brands were listed one way and the different rtcm messages the other way and one + in the table if needed. Last year my neighbor was on my F9P base which at the time when trying to connect to Raspberry zero, then the power went one day and he switched back on his expensive purchased rtk signal, but when he looked at year-end to pay again he would on my base again but we can’t get it, and I can’t remember which config file I had loaded at that time, he was running but an almost new New Holland (trimble). Now that time I sent via rtk2go mountpoint (hegnsgaardvej10) think I have tried sea of combinations also tried with inject 1008, just will not work again.

Relay his purchased stream through snip and see what’s in it?

Or is that not possible.

He’s probably having some login credentials and an IP adress + port number. Insert the IP + port into monitor.use-snip.com and you get a source table from the expensive one to see which messages are sent

Yes I realise that. That’s what I’ve done with his rtk2go mount point. What I don’t have any idea about is what proprietary paid providers can do (if anything) to prevent others analysing their data streams.

Its only caster information probably

There is no base station antenna reference point information (RTCM message 1005 / 1006) in your stream ballymagorry85 in the rtk2go.com -caster.
Maybe you have not turned it on or maybe the coordinates are not put right to the F9P.

I would suggest reading more U-Blox manuals of how to use U-Center windows software to set up the receiver. Also lot of other good stuff about the issue in the net:
Configuring the base manually - RTK F9P Positioning Solutions

Was looking your stream on RTK2go caster. Is your base antenna outside with an excellent sky view to all directions? Or is it maybe upstairs under a roof window? The signal to noise ratio (SNR) from satellites in the south seems to be somewhat low.

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There obviously was at some point because RTK2go still has 1005 listed and it will have parsed the stream itself.


It has parsed it again now and 1005 has gone.

@pniels, I can verify that for my Trimble 372 receiver, 1005, 1008, 1077,1087,1230 work. I believe 1074 and 1084 would also work.

EDIT: added receiver model for the record.

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Perhaps would be useful to mention the Trimble receiver model. Trimble has been on the market a long time, a long time before MSM messages were defined. Many old models would not support those.

Thanks it was smart, get the following answer so I got something to go for.
1004(1), 1006(10), 1008(10), 1012(1)

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Mine is a 372 (ag).


@torriem My neighbor is also pretty sure his is a Trimle 372 that is integrated into the New Holland terminal,but we can’t get it on my base via rtk2go MP hegnsgaardvej10, which sends the following 1004 (1), 1006 (10), 1008 (10 ), 1012 (1), 1077 (1), 1087 (1), 1097 (1), use your username and password, and are your Mountpoint name uppercase or lowercase letters