Labroides Posted at 10-6 04:15
What if your drone did start a RTH using data just before the GPS went off.
That sounds unlikely.
1.  GPS would have to returned to normal.

yes  i agree with you   unlikely

But the whole log is weird....

1. well, drone wasn`t in ATTI mode at the end....
2. don`t know, not important, what happend after the disconnect is 'important'
3. well, in post #10   hovering and flying away    last record position calculated close to HP, flying away could be bc RTH got acttive.....

Not shooting is always a miss, so better do a search there...

cheers
JJB

OP is in Croatia.  Is GPS jamming that uncommon?

https://www.linkedin.com/pulse/d ... atia-dana-a-goward/

JJB* Posted at 10-6 06:30
yes  i agree with you   unlikely

But the whole log is weird....

1. well, drone wasn`t in ATTI mode at the end....
Just a technicality .... GPS was not being used and RTH is not possible without GPS

2. don`t know, not important, what happend after the disconnect is 'important'
But the most likely reason for loss of signal given the circumstances, is loss of power

3. well, in post #10   hovering and flying away    last record position calculated close to HP, flying away could be bc RTH got acttive.....
So you said, but if it was, wouldn't the flyer have heard/seen it?

JJB* Posted at 10-5 01:22
Hi, In the CSV 2 columns ( OSD.xSpeed [MPH], OSD.ySpeed [MPH]) about speed, in the X and Y direction of movement. Result of the 2 values is the "XY" speed.

Sorry let me rephrase the question, do you think the numerical values of those speeds are accurate?
I.e. could the instantaneous speed multiplied by the time intervals give a supposed scalar distance travelled in that time interval.
The above works fairly well for calculating scalar distance flown but would need some playing with when dealt with as vector quantities.

Labroides Posted at 10-6 09:11
1. well, drone wasn`t in ATTI mode at the end....
Just a technicality .... GPS was not being used and RTH is not possible without GPS

1. well, drone wasn`t in ATTI mode at the end....
Just a technicality .... GPS was not being used and RTH is not possible without GPS
Understanding technicality is my core business,  OSD.isGPSUsed is TRUE whole log....In ATTI mode FALSE is written,what we do see in the log that the drone columns are not filled with data (only copy paste last good record, and so on)

2. don`t know, not important, what happend after the disconnect is 'important'
But the most likely reason for loss of signal given the circumstances, is loss of power
With a loss of power OP had to look out that his drone wasn`t falling on his head...as it was close to HP.

3. well, in post #10   hovering and flying away    last record position calculated close to HP, flying away could be bc RTH got acttive.....
So you said, but if it was, wouldn't the flyer have heard/seen it?
He saw his drone hovering shortly and moving away...as he brought his drone close to home after with RC input after 2 records of ATTI at 18m9.8s.
Why would it move away without pitch input ?
3 reasons for moving away without RC input  1) drifing on the wind in ATTI (not)   2) flyaway compass error (not)   3) RTH started (mayby....)


Just a thought....


cheers
JJB

Sean-bumble-bee Posted at 10-6 09:32
Sorry let me rephrase the question, do you think the numerical values of those speeds are accurate?
I.e. could the instantaneous speed multiplied by the time intervals give a supposed scalar distance travelled in that time interval.
The above works fairly well for calculating scalar distance flown but would need some playing with when dealt with as vector quantities.

yes  if you calculate speed using the X and Y vectors, the resulting speed is the actual speed.
So if you per record use this speed of time between 2 record you get the actual move distance.Or average speed over time to that time...


The CSV column OSD.hSpeed is representing this calculation.

If i compare 3 type of speeds (GPS, XY and OSD.hSpeed) value than:
  If drone is operating normal than:
     GPS speed equals XY speed (both calculated) and equals OSD.hSpeed
GPS speed is very accurate if GPS is receicing good data (almost always)
With errors in the log the XY speed remains longer the same to the GPS speed than the OSD.hSpeed.

see 3 speed charts for this log....

cheers
JJB

JJB* Posted at 10-6 09:46
yes  if you calculate speed using the X and Y vectors, the resulting speed is the actual speed.
So if you per record use this speed of time between 2 record you get the actual move distance.Or average speed over time to that time...

Thanks JJB.

JJB* Posted at 10-6 09:37
1. well, drone wasn`t in ATTI mode at the end....
Just a technicality .... GPS was not being used and RTH is not possible without GPS
Understanding technicality is my core business,  OSD.isGPSUsed is TRUE whole log....In ATTI mode FALSE is written,what we do see in the log that the drone columns are not filled with data (only copy paste last good record, and so on)

OSD.isGPSUsed is TRUE whole log....In ATTI mode FALSE is written,what we do see in the log that the drone columns are not filled with data (only copy paste last good record, and so on)
You should check that data again.
OSD.isGPSUsed shows False from 18:10.4 until the end of data.
That means that GPS was not used and this is confirmed by the position data.

Labroides Posted at 10-6 12:41
OSD.isGPSUsed is TRUE whole log....In ATTI mode FALSE is written,what we do see in the log that the drone columns are not filled with data (only copy paste last good record, and so on)
You should check that data again.
OSD.isGPSUsed shows False from 18:10.4 until the end of data.

oops, had the wrong CSV active.....

Thanks for the correction, but not comfirmed with data.
LatLon data copy paste, with False fields are not filled like this.

UPDATE:

Guys, I couldn't find my drone, but I reported the problem to DJI and sent them flight logs.
They concluded the incident was caused by the GPS error/product error and sent me a new mini 3 pro!
Hopefully, I'll have more luck this time.

Thank you very much once again and good luck with your flying and analyzing!

good result

Just curious...what exactly is the "cultural site" it was flying near?  Anything that might motivate someone to interfere with a drone flying over?

Burstmode Posted at 10-18 19:27
Just curious...what exactly is the "cultural site" it was flying near?  Anything that might motivate someone to interfere with a drone flying over?

Remains of an old fort on the hill, actually a historical site.

JJB* Posted at 2022-10-5 01:22
Hi,

In the CSV 2 columns ( OSD.xSpeed [MPH], OSD.ySpeed [MPH]) about speed, in the X and Y direction of movement. Result of the 2 values is the "XY" speed.

How did you stack the graph ? is there an option in CSview?

JeanbHarmon Posted at 8-14 01:06
How did you stack the graph ? is there an option in CSview?

Hi,

Not in CSview. I use FRAP.

cheers
JJB

Hi both JJB and Labroides,
I have a great time reading everything you have said and appreciate very much all your comments which has been very interesting to read.
Learned a lot from this information and what to look out for when flying over water. Very much appreciate all information. Great info in dead.
Cheers.

Mamelo Posted at 2022-10-4 16:15
Some kind of deliberate interference with the signal?
I was flying near a cultural site although not blocked on maps.

This article says it's strictly prohibited by your government to fly near an archeological site.

You don't think your government has drone jammers?  Really?
Military has them.  Police have them.  Security guards have them.

https://www.propelrc.com/drone-laws-in-croatia/

https://www.dvidshub.net/image/7751579/taking-down-drone

https://www.digitaleagle-uav.com ... mmer-pd6892290.html

DroneApe Posted at 8-14 11:20
This article says it's strictly prohibited by your government to fly near an archeological site.

You don't think your government has drone jammers?  Really?

This article says it's strictly prohibited by your government to fly near an archeological site.
You don't think your government has drone jammers?  Really?
It;s a big jump to assume that GPS jamming would be used at an archaelogical site.
It's about the most unlikely explanation.

Labroides Posted at 8-14 15:03
This article says it's strictly prohibited by your government to fly near an archeological site.
You don't think your government has drone jammers?  Really?
It;s a big jump to assume that GPS jamming would be used at an archaelogical site.

That’s your opinion.  Unfortunately you have no credibility left on this forum.  

TonyPHX Posted at 2022-10-6 07:47
OP is in Croatia.  Is GPS jamming that uncommon?

https://www.linkedin.com/pulse/daily-gps-jamming-zagreb-croatia-dana-a-goward/

It’s rare in USA, but not uncommon in Croatia. There are some people on this forum that think it's more likely to be Aliens than jamming.  It's the strangest thing I've ever seen on any forum.  If you ever want to have a laugh, look at the thread about "GPS glitch in Alaska".  It's hilarious.  Same with the "fall from the sky" thread from Corfu Greece.  And there's another one in the Virginia area outside of Washington DC on July 4th fireworks,  right after the June 29th Obama security incident in DC.  It's absolutely comical.  The dude literally posted a video of the drone under power recording video descending after being jammed (both Wi-Fi and GPS)--yet they were claiming it must have had a "sudden loss of power". They seriously don't get it.  

There's a multi billion dollar drone mitigation industry being developed right now to keep up with the multi billion dollar drone industry.  

DroneApe Posted at 8-14 18:42
That’s your opinion.  Unfortunately you have no credibility left on this forum.

Credibility ?
You can talk ... suggesting GPS jamming when it's the most unlikely explanation.
You seem to have a tenuous grip on reality.

Labroides Posted at 8-14 20:07
Credibility ?
You can talk ... suggesting GPS jamming when it's the most unlikely explanation.
You seem to have a tenuous grip on reality.

Again, that’s nothing more than your opinion.  You lost all credibility. And you know it.

DroneApe Posted at 8-14 22:06
Again, that’s nothing more than your opinion.  You lost all credibility. And you know it.

Again, that’s nothing more than your opinion
Wheras you have plenty of evidence to support your unlikely guess?

You lost all credibility. And you know it.
That would be another unsupported guess, something you seem to specialise in.
How many flight incident mysteries have you solved?
Did you ever have any credibility to lose?