"Hi Alex,
Sorry it took a while to respond, but lets go:
> not sure about the "new"-ness of this featureI never claimed it was new.
> I don't think your unit is IP64 rated either, even without an AS sensor, so let us not go thereAny vehicle with…"

"Hi Tom,
I never suggested this was anything new on PX4. It's been available for almost 2 years now."

"No, that would require an impossible level of fine tuning on your actuators"

"@andreas 
You need to distinguish between 2 processes:
1. Keeping the vehicle flying stable2. Estimating airspeed

Process 1 only uses estimated airspeed to scale actuator outputs (elevons). The transient phase is not a real concern there. It uses a…"

"If you know the voltage, motor IR, motor KV, prop size, type and pitch angle you can calculate thrust. a bit like how eCalc does it.
But from a control perspective the absolute thrust value is not as relevant, its about knowing the scale factors,…"

"Also, you cannot compare GPS speed to airspeed unless you fly perfect circles and average the wind factor out."

"Hi D J,
We eliminated the pitot tube and AoA sensor. The voltage sensor is used (among others) to compensate.

You can try calibrating such a setup by mounting it on a car (we did that too), but you will find that the drift will happen in your UAV…"

"Hi Patrick,
Looks good, i'll forward this to our other NGO partners, they will surely be interested.
PS: the TEDx link below your post is deadPS2: love the dramatic DeltaQuad picture at 6:50 in the video :)"

"The image i selected depicts the convoluted and fragile setup required to get airspeed readings on a UAV, In this case indeed it includes an AoA sensor."

"Perhaps i was not completely clear on my previous comment. When i mention voltage i mean the data from the voltage sensor, so you get the exact voltage sent to the motor, this accounts for voltage drop and does not require internal resistance. We do…"

"@Andreas: voltage and known thrust curve of the motor"

"Hi Mike,
I did not say it was "just released", i wrote one about 12 months ago.
http://docs.px4.io/en/config_vtol/vtol_without_airspeed_sensor.html"

"@Mike
Thank you for your kind feedback :)
> Other onboard sensors have similar or even worse problems than those mentioned
You are correct that drift occurs on the other sensors too, however, the drift on those sensors, although significant to the…"