How the FAA know the pilot violate the reguation?

[iaincaradoc]

The reference point is the elevation of the takeoff point, and the height during the flight is primarily determine by barometric pressure.

I was kind of surprised to learn that they're using barometric for altitude, until I realized that if horizontal accuracy is about ten feet in a *good* consumer GPS device, and the vertical accuracy is about three times the horizontal... a deviation of thirty to seventy feet with sUAS could be problematic.

 

[sar104]

I was kind of surprised to learn that they're using barometric for altitude, until I realized that if horizontal accuracy is about ten feet in a *good* consumer GPS device, and the vertical accuracy is about three times the horizontal... a deviation of thirty to seventy feet with sUAS could be problematic.

It's generally much better than that, especially with WAAS, but that is the basic reason. Barometric relative height, at least around the starting elevation, is generally better. With WAAS and plenty of satellites the GNSS altitude tracks better than barometric height as the aircraft ascends.

 

[MavicFlyer]

While you bring up a good point, keep in mind is that there is a difference between reading a statute, and understanding the case-law that goes along with it. Also, the Mens Rea aspect of the crime (the "knowing" part) can often be proven by circumstantial evidence (it happens every day), and no trial is ever guaranteed. Last, the prosecutor / states attorney doesn't need to prove every element of a crime just to make an arrest, and the elements are always arguable either way. Lots of convicted folks out there who thought that an element of a crime couldn't be proven. ??‍

Another aspect that one would have to consider is that if there is a trial, then there will have necessarily been an arrest (even if you turn yourself in). That arrest record will follow you, even if acquitted. Then there is the matter of the money that will have to be spent. Even if the case doesn't make it to trial, there will be a cost involved with retaining counsel to try and work some sort of pre-trial intervention, if it DOES go to trial ... whoa momma!
Then there is the time away from work, and a whole host of ***-pain that goes along with the territory.

I can't disagree with anything you said.

It just reinforces what I've known for decades:

Even if you are acquitted in court, you still lose.​

The best way to deal with the law, is to NOT deal with it.​

How much justice you get is a function of how much you're willing to spend to buy it - sad, but true.☹​