Altitude using Tfmini Lidar

#1

FIRMWARE : Arducopter 3.6.8
Pixhawk : Pixhawk 2.1 cube

I have connected the tfmini lidar to the gps2 port of the pixhawk.
Although I am able to get a correct reading of the rangefinder altitude, the relative altitude is using barometer (maybe fused with the lidar data).
The problem is that the relative altitude keeps fluctuating due to the barometer, which I don’t want because below a certain height I want my altitude data to be purely lidar based. So the parameters are as follows:
EKF2_ALT_SOURCE = use rangefinder
EKF2_RNG_USE_HGT = 15%
RNGFND_MAX_CM = 700
RNGFND_MIN_CM = 20
RNGFND_TYPE = 20

But there seems to be a heavy effect of the barometer, can we decrease that weight or purely use rangefinder without fusing below a certain altitude
other values are default

#2

@sidbh

#3

@Pence, Welcome to the community!
So, per your parameters, the EKF will use the Rangefinder as the source of height only below 105cm(1.05m) i.e. 15% of MAX range i.e. 700cm only. If you think the Rangefinder data is not being fused even when the conditions are met, please share the dataflash log, so we can analyse further.