Welcome Inspire Pilots!
Join our free DJI Inspire community today!
Sign up

Fly-aways in Australia

agree. we will never ever get something more precise since civilians are always a potential threat ... no offence meant to anyone and this is my personal opinion.
Surveyors use sub-centimetre accurate GPS every day of the week.
Civilians have had easy access to high precision GPS technology for years.
 
  • Like
Reactions: Paul Moran
Thanks Meta4 for your answer once again.
I would like to ask if there is a difference between northern and southern hemisphere on the number of sat's available to our Inspire sat reciever's at any given time.
On my other auto pilot osd I have seen up to 14 sat's available , allowing for the different types of sat systems ( some not used for our systems ) does the southern hemisphere have more or less usable stat's than the north.
In this Inspire forum some pilots are asking DJI for a sat count to be shown on the DJI app screen.
I take it , this would then show that the Inspire requires a given number of useable sat's to hold opti lock.
Dropping one or two sat counts below this required settting would then cause the Inspire to loose opti lock and go into atti mode for the amount of time until the required sat count is re established.
What would the Inspire GPS HDOP setting be for the Inspire????.
If the Inspire 1 or other auto piloted uav's do not get the correct sat count "at the point" of setting the home position...it definatly wont be able to set home point after it is airborn or moving ...hence ...fly aways.
I just like to have a firm understanding of the systems that control my 4k investment when it is in the air..... to be a responsible pilot as well.
...Pete
 
I would like to ask if there is a difference between northern and southern hemisphere on the number of sats available to our Inspire sat receiver's at any given time. ... does the southern hemisphere have more or less usable sats than the north.

GPS satellites aren't fixed in the sky. They orbit the earth - they're constantly moving through space.
Inside the birdcage they make around the earth, our planet is rotating on its axis like this.
4457788776_a0dafeec28_o.gif

North or South or anywhere else - it doesn't matter where you are.
GPS is a Global Positioning System

If the Inspire 1 or other auto piloted uav's do not get the correct sat count "at the point" of setting the home position...it definitely wont be able to set home point after it is airborn or moving ...hence ...fly aways.
So it is important to ensure that your home point is set - and easy to check this after launch rather than assume it is set and perhaps only find out when it is too late.
 
Hi Meta4.
Well ....that's what I call an answer.
I must say how impressed I am with your reply.
May I now.... make a "educated" answer to the question first asked at the beginning of this thread that,
1.....there is no real difference between the northern and southern hemisphere towards the number of sat's available to our Inspire 1 sat recievers.
2....from your well presented working explanation of global orbiting of the stat's that there will always be a difference between how many stat's our Inspires can lock onto.
3....my observation's is there could be available anywhere between 6 to 12 usable sat's available depending on the orbital position of the sat's relative to our position on the planet.
4.... loss of satellite lock for our Inspire 1 is fully dependant on the DJI software setting on how many stat's are required to maintain a positive lock for opti mode.....hence the reports of dropping from opti to atti and back to opti modes several times during one single flight time.
5....incorrect time allowed for the setting of home position before take off.
6.... or attempting take off outside of (green) Opti mode...but attempting take off in ( yellow) atti mode.... and then expecting the Inspire to return to home point when problems are evident...when no home point was allowed to be set.
As a conclusion .....to my attempts to ask far fetched questions with the assistance and patients of your reply's....we are better prepared to understand why...when and how our Inspire 1 react to loss of GPS lock.
To confirm satellite lock and home point is set correctly....initiate return to home function after take off ....at a safe height and distance from launch to see if the return to home response by the model is correct....something I do with my fpv auto pilot every flight.
Understand that if this loss of sat lock happens...the model is still under your full control in atti mode...so learn how to fly and recover the Inspire 1 in atti mode before attempting those first great video/ photo flights .
Thanks Meat4 for all your comments.
....Pete
 
3....my observation's is there could be available anywhere between 6 to 12 usable sat's available depending on the orbital position of the sat's relative to our position on the planet.
There are a few more satellites in the GPS constellation since that animation was made.
I've managed to get up to 16 with a Phantom.
The Inspire uses Russian Glonass satellites as well as the old fashioned US ones so it should find even more but I'm not sure how it handles the combination.
 
There are a few more satellites in the GPS constellation since that animation was made.
I've managed to get up to 16 with a Phantom.
The Inspire uses Russian Glonass satellites as well as the old fashioned US ones so it should find even more but I'm not sure how it handles the combination.

Meta4 Glonass ??? Are you sure. I really hope so. I'm a surveyor so if the Inspire uses Glonass as well then definitely no issues with GPS signal. If GPS only then sometimes the satellite health can render a satellite out of commission for a period of time and although you might be flying high multipath around buildings can also be an issue
 
just a note on the GPS - the USA have several times enabled selective availability which fundamentally introduces an error to the civilian GPS market, the new p3 has a dual band receiver GPS & GLONASS) which should have been included in the Inspire if it was intended as a flagship device. Dual band would keep a better fix and I doubt we will have any where near the number of fly away victims using the P3 as a result (if they are honest and admit they neglected to calibrate).

The Inspire 1 does use both.
 
US Government has used selective availability from time to time - this introduces a deliberate error into civilian GPS recievers and GLONASS being Russian would be no different. Most Survey equipment, even RTK gear takes several minutes if not longer to initialise and UAV users are turning on devices and flying away in minutes if not sooner.

As an engineer I would like to see some testing on the minimum number of sat's required for a good fix (not just the DJI >6 statement for an A2 or wookong system) to determine if the sensor has had sufficient time to really know where it is AND if the flyaways do not tend to be in the direction of the previous flight - possibly some coordinate artefact in the system somewhere, you loose signal and it heads to a known coordinate ??
 
US Government has used selective availability from time to time - this introduces a deliberate error into civilian GPS recievers and GLONASS being Russian would be no different. Most Survey equipment, even RTK gear takes several minutes if not longer to initialise and UAV users are turning on devices and flying away in minutes if not sooner.

As an engineer I would like to see some testing on the minimum number of sat's required for a good fix (not just the DJI >6 statement for an A2 or wookong system) to determine if the sensor has had sufficient time to really know where it is AND if the flyaways do not tend to be in the direction of the previous flight - possibly some coordinate artefact in the system somewhere, you loose signal and it heads to a known coordinate ??

My standard operation proceedure now includes at least 2 minutes of control checks before I head away from the home point.
 
Old thread new life.

The issue I had was a fault with the firmware at the time. Looking at the logs you could see the drone was dropping GPS and going ATTI it was cycling modes in the air. I saw this in latter logs with my second I1 but not as bad. After a few firmware updates the cycling between GPS and ATTI stopped.

There was at the time a lot of user error as well with flyaways. However at the time of this post DJI had some very bad firmware that caused a lot of flyaways
 

Members online

No members online now.

Forum statistics

Threads
22,277
Messages
210,656
Members
34,329
Latest member
defenderschool