Hi,

Im in the middle of an argument about GPS accuracy and a statement someone has just made.

The statement was :-
You should power up your drone and leave it on the ground for 15 minutes and it dramatically improves the GPS accuracy because the drone learns the errors.

Now this to me is bull..., RTK uses a static ground point and can over time see what the errors for each satellite passing overhead, send the correction up to the drone which then reacts accordingly. I dont see any way at all that the drone can 'learn' the error which in my will vary with satellite position anyway, as it drops down to the horizon the error will increase.

Can anyone confirm or deny the statement above?

Thanks - J

Sounds like BS to me.  Who wants to sit waiting for fifteen minutes?  That's just stupid.  

I wouldn't call the less than perfectly accurate satellite fix an error.  I would say it's either within specs or not within specs.  But even if it's not within specs, that doesn't mean there is an error in the system.  The system can only do what it's capable of doing relative to the visible satellites at a given location.

It's true that waiting a bit will potentially improve accuracy of the "fix" relative to the surface of the earth.  That's because waiting a bit allows the GPS/Glonass module to acquire more satellites for more accuracy.  IMO, 30 secs is usually plenty of time.  Sometimes you might want to wait for up to a minute or so.  If the accuracy is off by a few feet, so what?  Also, once you launch and the elevation mask decreases, satellite fix accuracy will improve dramatically, even if your home point is a bit off.

Also, just my own rant, I hate the acronym GPS these days.  It's like Kleenex.  Not everybody uses Kleenex only, and not everybody uses GPS only.  I like "satellite fix" better.  MHO

Good luck

I don't see the rationale here. Could be BS

Well, its close to that with my P4P before she tells me im good to fly compared to my mates Mavic pro

In other news, is this smiley waving or saying someone floated a cheese biscuit?

Its BS.

What they may have confused it with : Circle of Errors ... or Circle of Precision (depends on which side of the argument you are on !!).

GPS recvr. receives sat data, computes position, passes it through filters which compare to reject what it believes are erroneous positions. The recvr is computing position repeatedly and passing that info through its filters and  as before rejects those it computes outside of Circle of Precision.

A boat plotter is an excellent machine to see this on.  Leave it on for an hour or longer and the plot is like someone has taken a marker pen and randomly plotted all around the boat. Very few are actually spot on position of the boat ! You can see speed and direction figures changing even though boat is not moving.

OK - so why does our DJI not do similar ...... its using averaging, so it keeps as best it can to a reasonable track and speed etc. as well a positional data. So in fact it does do similar but the averaging masks it well enough for us to accept its displayed figures.

We will leave out Car Navs ... they use averaging but also what is called 'Jump to Road' which further reduces the jumping around of plot.

It doesnt matter you wont get good GPS accuracy if you leave the sitting for 15 mins, for good accuracy is basically how many satellites are in your view at one point. which is mostly 3 or 4. which still has a margin of error too

Mark The Droner Posted at 6-9 15:21
Sounds like BS to me.  Who wants to sit waiting for fifteen minutes?  That's just stupid.  

I wouldn't call the less than perfectly accurate satellite fix an error.  I would say it's either within specs or not within specs.  But even if it's not within specs, that doesn't mean there is an error in the system.  The system can only do what it's capable of doing relative to the visible satellites at a given location.

"Also, just my own rant, I hate the acronym GPS these days."

I would agree, it should really be GNSS of which GPS & GLONASS are but two systems.

BagoDJIoperator84 Posted at 6-10 14:53
It doesnt matter you wont get good GPS accuracy if you leave the sitting for 15 mins, for good accuracy is basically how many satellites are in your view at one point. which is mostly 3 or 4. which still has a margin of error too

good accuracy is basically how many satellites are in your view at one point. which is mostly 3 or 4. which still has a margin of error too
If your receiver is only seeing 3 or 4 sats, something's wrong.
If you are flying in the open rather than in a deep canyon etc, you should be getting lots more than that.

Um 15 minute warm  up doesn’t leave much flight time.
Think term GPS  has morphed into generic term for most users these days.

The Term GPS came about to differentiate from the previous Transit System.

Transit was not Global and had severe limitations in various latitudes due to cyclic bunching of sats passing overhead. For example in S. China Sea ... over 10 days the sats would bunch up and you would have fixes bang bang bang after each other ... then hours of nothing. Over days - the sats would spread out but 10 days later back bunched up again. (I was Nav Officer on vessels that were trialing Magnavox Transit....)

GPS came along and suddenly we had near global coverage and evenly spaced sats that as long as above the 'event horizon' could be 'read' continuously. Thus the term Global Position System came about. It has become by its common usage the term used.
Even more that it is common to hear that People use term GPS for just the US based system.

Aardvark Posted at 6-10 15:02
"Also, just my own rant, I hate the acronym GPS these days."

I would agree, it should really be GNSS of which GPS & GLONASS are but two systems.

I like it!!!

I hate the acronym GPS these days

Come over here then ... ALL 4x4 's are called Jeeps here ...

In many countries a vacuum cleaner is a Hoover ...

Many items in life have incorrect 'names' given to them.

I have two pet hates :

Laptop .... for anyone old enough - a Laptop was actually a folding mains powered heavy beast that was superceded by NOTEBOOK computers which is the more correct term for todays portable 'laptops'.

Drone ... for our Multi Rotor craft, when in fact Drone was used to name unmanned remote craft air and water and later became connected with Military unmanned aircraft.

I've been using DroneDeploy and the images are pretty much spot on and it's not RTK.