On Friday, May 17, 2013 2:59:18 PM UTC-6, son_of_flubber wrote:
On Friday, May 17, 2013 2:23:21 PM UTC-4, Mike the Strike wrote:

The advent of varios with inertial probes that enable the compensation or identification of horizontal gusts



So does the ClearNav

1)have an inertial probe and

2)does it have the software (at the moment) to filter out horizontal gusts?



So does an "inertial probe" and an "accelerometer" both provide the same sensor inputs to the software?

I'm not sure how it is actually being implemented but I would interpret "inertial probe" as an IMU (Inertial Measurement Unit). IMU's have 3-axis gyros and 3-axis accelerometers. The gyros keep the accelerometers aligned up-down, east-west and north-south. MEMS IMU's these days are nearly chip-size so one could be inside the vario with GPS position data serving as a calibration signal to compensate for drift. This means vertical acceleration can be measured and the integral (velocity) can be displayed as a vario signal. The advantages of an inertial vario include zero lag, gust insensitivity and complete freedom from TE probes and associated plumbing.

The gust/thermal discrimination is done by comparing the inertial-TE with air-data TE. If the air-data shows a gain in total energy but the inertial data doesn't, it's a gust.

The above is the most elegant implementation but partial implementation could also provide an advance over the old air-data only varios.