Looking for better GPS / MAG sensor for Pixhawk clone

Hardware Pixhawk family
1

Hi everyone, looking for some experience based opinions on reliable GPS & MAG sensors,

I have 2 knock off GPS units that I bought cheap. They pick up a lot of sats and get a low HDOP but wander a LOT. So now I’m in the market for a better GPS & MAG sensor and trying to find the best options.

I’m interested in the Here+ RTK GPS (RB-Htl-01) here: https://www.readymaderc.com/store/index.php?main_page=product_info&cPath=505_778_781&products_id=6452

Unfortunately, I don’t know if it will work since the only instructions I can find are specifically geared toward RTK which i’m not interested in at this time or only for the Pixhawk 2 cube. The ground plane, sensitivity, dual mag sensors and other features make it seem like a nice GPS unit. $48 + $3 shipping = $51 total.

I also read great things about this:

but while the price isn’t bad, the shipping to the US is a killer. $47.13 for the GPS, $27 for shipping = $74 total.

Both units incorporate NEO-M8N as well as HMC5983 MAG but the Here+ also has a LIS3MDL mag.

I would love to use the Zubax GNSS Positioning Module — GPS, Compass and Barometer but @ $150+ it is out of my price range. http://nicadrone.com/index.php?id_product=56&controller=product

I also considered the RadioLink SE100 since it is cheap but have heard very mixed reviews of it as well.

Any input is very much appreciated!

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Just get the HERE GNSS ( the one you linked to at readymaderc).Not the HERE + (which is the RTK expensive flavour).Be warned - they are big.It’s fit and forget GPS and a compass but you’ll need a lead.They should have made the difference clearer to my mind but the + is the technical one and the HERE just a standard GPS/compass unit.

I also like CUAV parts.Nicely made.I hope Drotek stuff is good as I just ordered two units from them for my Solos.In the States mRobotics is a good place to shop.

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Thanks for the input! I didn’t realize there was a difference between the 2 HERE models. Great info! I’m putting it on my F550 Hex, planned on setting it right in the center of the top (empty) PCB. Do you know if it is recommended to mount a GPS like this (with included 6cm ground plane) on top a mast / tower like others? I assume it would connect same as the HERE+ http://ardupilot.org/copter/_images/here-plus-pixhawk.png

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The more I think about it, it still makes sense to put it on a mast to get it away from the other electronics. The ground plane is for GPS gain, not interference.

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If the wander you are seeing is with the aircraft sitting on the ground, it is perfectly normal.

The deal is, when the aircraft is on the ground the EKF is basically using sensor noise.

Read this: http://ardupilot.org/dev/docs/extended-kalman-filter.html

As the saying goes, “The proof is in the pudding,” so set up a switch to trigger RTL and then take the aircraft out and fly it around, test Alt Hold/Loiter/PosHold and then trigger RTL.

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