Tyro129 BN-220 GPS works great when sky is clear but loses signal several times during a flight when there's thick cloud cover. Is there a better GPS that would plug in using the same cable? Flights are getting longer, so would like to make sure GPS rescue is always available.

https://www.amazon.com/Beitian-Navigatio...B07WM1GFY8

It’s tough reading the specs of a GPS module to decide if it will perform better or worse compared to other GPS modules.

The better tuned a GPS antenna, the larger the size of the GPS antenna, the lesser electrical and RF noise in the system you have will affect performance.

If you are doing flips and rolls around large buildings or trees, you will lose satellites simply because either the signals are being blocked or the antenna is positioned away from the sky.

Ardupilot for example has documented abilities to extrapolate/project/estimate the position of the craft to a certain distance if it losses GPS satellites. Betaflight on the other hand may not have such abilities.

Some people swear by Mateksys GPS units but I have even lost satellites mid-flight with a Mateksys GPS when doing rolls or inverted yaw spins. You can’t defy physics.

Should you be concerned? Think for a moment how GPS rescue works:

- If you had a GPS fix and home position set at take off
- at some point you lose failsafe
- the quad will stabilize itself before it initiates a return towards home
- at this point in time assuming you accelerometer is working the GPS will face the sky
- the distance and direction will be calculated and the quad will fly towards the home position
- during this phase the GPS data is constantly evaluated and the flight path is adjusted to ensure its heading in the correct direction towards the home point

Another question is, if you failsafe do you actually need GPS rescue all the way back? Not really. Once you establish video and rc link its always best to take over by moving the sticks on the transmitter.

I fly long range in remote areas and just slow cinematic style. So I guess a strong signal/cloud penetration is what I'm looking for in a GPS. I don't want to find out what happens if I fail safe a long way out and don't have satellites

Even with a Mateksys M9N-5883 onboard, no one can guarantee you will be able to get your quad back.

try to get more separation...

I found the tiny matek module sam m8q having a very good reception (>20 sats)

(23-Sep-2021, 02:49 PM)jasc Wrote: try to get more separation...

I found the tiny matek module sam m8q having a very good reception (>20 sats)

GPS sits at the highest available point of the quad, on top of the gopro. I also always have around 20 sats and have never lost signal when sky is clear . But thick cloud cover makes it very unreliable.

Just want to make sure I've done what I can to minimize the chance of losing the quad, so if there is a better GPS available I'm gonna stick that on.

As you are generally getting good satellite reception with the GPS module you already have it is clearly performing well on your quad under normal conditions. I therefore think you will face the same issues with any of the GPS modules with heavy cloud cover. The best you can probably do to mitigate the problem as much as you can is to get a GPS module which has the biggest antenna you can find. The Beitian BN-880 and the Matek M9Q-5883 modules both have one of the largest GPS antennas available for a standalone GPS module.

(23-Sep-2021, 03:36 PM)SnowLeopardFPV Wrote: As you are generally getting good satellite reception with the GPS module you already have it is clearly performing well on your quad under normal conditions. I therefore think you will face the same issues with any of the GPS modules with heavy cloud cover. The best you can probably do to mitigate the problem as much as you can is to get a GPS module which has the biggest antenna you can find. The Beitian BN-880 and the Matek M9Q-5883 modules both have one of the largest GPS antennas available for a standalone GPS module.

Largest antenna makes sense, thanks!

Looks like BN-880 is even plug and play with my FC:

https://ibb.co/p0LLgxr

https://ibb.co/Hh6XTbp

Edit: Nah, have to move pins around a bit.

I have the Matek M9Q-5883 on my 7”. It is way more reliable than the M8Q-5883 I have on the 5” quad. I find the altitude on the M8Q-5883 to be jumpy for lack of a better term. The gps altitude on the M9Q-5883 is way more believable. I have had to enter coordinates in an app to locate the quad and the coordinates in the googles were dead on and found the quad.

i had bn220 and had many issues with it
https://intofpv.com/t-gps-rescue-why-it-...ot-to-home

M8Q-5883 72 i use now and it is perfect

the noise from your gopro is probably messing with your gps.

(25-Sep-2021, 02:20 PM)p-i-engineer Wrote: the noise from your gopro is probably messing with your gps.

Negative. It works flawlessly 100% of the time when sky is clear. Thick cloud cover is the only scenario where I lose sats.

I ordered the BN-880.

Hmmm, I would have guessed the gopro would be the cause too. I struggled with this on a small 7" quad myself and never had issue without the gopro. Maybe it worked marginally ok but with the introduction of clouds attenuating it made it more noticeable? Don't know, will have to take note of this on future builds. Let us know what you find with the new unit, I might have to try it myself!

my bn-180's work great even with cloud cover, but they're spaced away or have they're wires shielded and grounded.