Dual GPS output format for AOG

Hello, which heading do you use?

I am using ads, f9p, ublox antena and Brick. Using 2 antena is there a big difference with accuracy?

I thought your re using dualheading.

There is no dual heading, there is a dual GPS that defines coordinates and heading

Hello, has someone experience better precision with dual antenna heading and roll ? or is it too soon to go for ?
Thx

Hello, Iā€˜m using dual heading from AOrtner. On a flat field it works well.
When the tractor sways the heading is a little bit unstable.
On the otherside you can stop and go on and you are stable on the line.

have you seen a terrain compensation (i e you come from both side of a inclined field(hill side) and are guided on the same track ?
Thx

The reason to use 2 gps to generate a heading is so you can avoid getting the heading from a magnetometer
Magnetometers are very susceptible to error due to magnetic interference and the dual gos is not
One gos is set up in moving base the other uses a fixed base
The output of this is a fixed position and an accurate heading

That, i did understand, what i wonder is if you have 2 antennas side by side at a certain distance, then you could probably calculate a Roll as a machine never really slide much and the difference of altitude and more could give you a roll degree and so the need for a Roll sensor could also be avoided.

Yes
the dual antenna system id so accurate that if you orient the antennas at right angles to the longitudinal axis it will give you roll. It also provides position and heading
Max

any experience with AgopenGPS ?

What happened to your github repo @Aortner Aortner?

Very intrested in trying to run a dual simplertk2b setup for accurate heading, but struggling with how I can get the heading input into AOG. Thanks

sorry its active now againā€¦

Thanks for that @Aortner , how are you getting on with it? Assume you have the two antennas mounted to the left and right of the roof? Do you just set the AOG antenna offset (side to side) to the primary F9 antenna?

It would probably be best to take the average of the two antennas. is that possible?

Always seems ā€œwrongā€ settings the receiver off center with an offset, but putting them front - back would loose the ability to make roll calculations using the two which I think would be a shame.

As you say Brian an average / the center point would be ideal but guess that would have to be calculated via the Arduino being used to calculate the heading / roll using Aortnerā€™s codeā€¦

Got dual GPS to work with 2 Ublox f9p and esp32. Data can be transferred via USB or Wi-Fi.
It corrects the position by using roll and creates a virtual Antenna position.
Just an early release.

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I see you have antenna height in set-up, what would we need to set Aog height setting?

When using two antennas do they each produce a fix at exactly the same time or close enough to? The reason I ask is because I notice youā€™re applying the kalman filter to the calculated roll before computing the virtual antenna position. If the two positions are computed at the same time, why is the kalman filter needed at all? After all if antenna 1 is position x, and antenna 2 is position y, then the compensated position is known to a high-ish degree of accuracy is it not? I suppose the accuracy of GPS is probably around 4cm for altitude, so after extending that to the ground, the accuracy of the fix itself could be significantly reduced, and thus noisy.

Also Iā€™ve been wondering what value for the earthā€™s radius to use when doing these calculations. I looked at the UTM transforms and while they are ellipsoid, not spherical, they seem to use two value, 6378137 and 6356752.314, at least for the common WGS84 ellipsoid. I notice you used 6371000.8 metres. I suppose the best value here depends a lot on where one is in the world. I found that a value closer to the larger UTM value seemed to be pretty close to the results I got by converting first to UTM and then adjusting for roll and offsets.

[quote=ā€œBrofarm, post:58, topic:184, full:trueā€]
I see you have antenna height in set-up, what would we need to set Aog height setting?[/quote]

Iā€™m assuming zero since the sketch already compensates for roll and generates a virtual lat/lon position thatā€™s already on the ground as it were.

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