The intent of this page is to explain how a barometric vario works, what you can expect from smartphone variometers and sensors and how you might benefit from an instant vario and why you will need a variometer for paragliding in general.
An instant variometer has virtually no delay or lag in calculating the vertical climb rate (vertical speed). What you feel is what you hear. And this makes for a much more intuitive flying... ¯\_(ツ)_/¯
Small bumps in the air can be felt and heard, lifts are easily identified and in weak conditions a zero delay indication of the vario can help you stay in the air much longer. It just flies different and thermals are much easier centered.
This instant feedback can be provided by most of the current middleclass smartphones using the FusionBoost algorithm of theFlightVario instant vario. theFlightVario takes readings from all motion sensors, especially the
and last but not least the barometer and calculates a fused climb rate. Combining all these readings at rate of up to 100 times each second straightens out individual errors of each sensor and make the fused signal non delayed.
How does a variometer work?
What is an instant vario
Remember, a basic vario for paragliding uses the variation in pressure to calculate the difference in altitudes and from that difference the climb rate. However, that difference in altitudes will need to happen first which is why a barometric vario, one that is based on pressure alone, will be delayed, always! It can only indicate lifts or change in altitude that already happened ¯\_(ツ)_/¯
That said, there is another variation, more instant, that can be used to calculate the change of the climb rate. And again it is about relative change rather than absolute values.
Acceleration - the instant in the vario
How does an instant variometer work?
The instant vario for the paragliding pilot
Calibration algorithms included
Since no smartphone is identical to another with regards to its sensors, the Flight Vario App includes calibration algorithms to get the most out of your smartphones IMU and barometer. The algorithms are tested across Google, Nokia, Samsung, LG and Xiaomi devices with BMP280, BMP285, BMP380 and LPS22H barometer as well as accelerometer and gyroscope.
In case you're wondering what and IMU is or actually does: IMUs combine a gyroscope with an accelerometer in one chip and enable your smartphone for real-time motion detection which can be used to enhance the classic variometer based on pressure sensors as discussed in the previous lines.
Feedback on instant vario
Since the start of the instant vario feature we collected some feedback which can be summarized as follows:
Beginners vs. experienced pilots
The feedback we got so far underlines an interesting but no unexpected fact that we also noticed when developing the instant vario algorithms. If you are used to flying with a classic vario and a delayed response, you might need a little retraining (learning curve) on getting what you feel working together with the instant varios output. As a beginner this (re)learning curve is not experienced, it feels natural from the beginning.
Feedback on smartphones
We also got some feedback regarding smartphones that seem to have the technical requirements in terms of barometer, accelerometer and gyroscope (IMU) to provide the instant vario feature. But please, keep in mind that we cannot guarantee for the general fit of a mentioned smartphone since it is not possible for us to test each phone.
Smartphones with barometer for instant vario
the following smartphones with integrated barometers were reported by pilots (exact model year not known):
Please get in contact with us if you have information on smartphones not listed here already.
Note: We restricted theFlightVario to smartphones running at least Android 8.0 aka OREO due to enhanced GNSS features.