yes I did "compass" and "acceleration meter" calibration several times but not on a regular basis, normally I do it under the request by the controller or I move to another spots sometimes it becomes "ready to fly", but in the wide open spaces I usually get the message "ready to fly", then why we should calibrate again, this comes back to the point that can we rely on the "ready to fly" message, if not what can we do when somebody lie to you?
Lying: "To make an untrue statement with intent to deceive." (Dictionary)
Your drone doesn't have an "intent" to deceive. If you don't re-calibrate your compass or accelerometer, the drone doesn't know any better, it may think everything is okay when it isn't. If your drone doesn't detect any interference, if it detects that the landing gear is fully extended, if it detects that the arms are fully extended, if it detects that the camera is on...that the gimbal and stabilizer is connected and working correctly...if it detects that you have a minimal GPS connection that will allow you to launch safely...In that moment...the drone doesn't register anything wrong. As far as the drone is concerned, you are "ready to fly".
There are many things the drone doesn't run a diagnostic check for. For example... is your battery seated correctly? Are your props screwed on correctly (tight..white on white, black on black). Are there any defects with the body of the drone?
It also can't anticipate or predict future or external events (compass issues, GPS issues, high winds, KP index issues, temporary flight restrictions, etc.). Drones are much "Dumber" than we give them credit for. As I said above, You could certainly consider this a "limitation of the technology"or lack of mature technology, and I do think we need to take notice of where these limitations are, and how to avoid potential problems.
Experiment: Take all your propellers off the drone. turn it on and "arm" it as if you are preparing to fly it. If outside, even without propellers, the drone will say "ready to fly". Is it ready? What would happen if you tried to fly without propellers?
Is the drone "lying" if it says "ready to fly" in the above conditions? How would the drone know any differently? What if you only had two props on the drone (
don't really try this...you will crash)? What if one prop breaks immediately after take off? Would the drone be "lying" if it said "ready to fly" and you took off into a 65kph wind? If it isn't able to anticipate high winds, how would your drone anticipate compass interference or GPS loss prior to flight?
I think you could call this a "limitation in the technology", but there are ways you can anticipate and avoid these types of issues.
Here are a few suggestions from Go Pro's Community Hub on how to mitigate potential problems:
Solved: PLEASE READ if you plan to fly - GOPRO SUPPORT HUB
It sounds like a long list...but literally takes seconds to do.
Even Gopro's official website offers a significant number of things you should do (including re-calibrating your compass) before getting to that "ready to fly" message. Even then...Gopro recommends that you wait an additional one or two minutes to acquire additional satellites before actually launching:
https://gopro.com/help/articles/question_answer/Karma-First-Flight-Tips
Like you mentioned earlier...I typically hover for a few seconds to assure everything is working as it should.
When I see "ready to fly", I'm reading that the drone didn't detect any current issues, and is ready for me to press the "start" button.The drone is not assuring me that I will have a safe or perfect flight. If I have done all the pre-flight checks as listed above...I'm much more likely than not...to have a safe interference free flight.