Power spectral density unit conversion

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Hello,
Is there a quick way to convert the Noise Power Spectral Density of the accelerometer from 300µg/√Hz to m/s^2 as an acceleration unit?
Thanks.

Accepted Answer

Devineni Aslesha
Devineni Aslesha on 20 Apr 2020
To convert the Noise Power Spectral Density of the accelerometer as an acceleration unit, see the code below.
psd = 300*1e-6;
w = 2*pi*f; % f is in Hz
psdToAcc = psd*sqrt(w); % Converting psd to acceleration unit 'g'
gTomps2 = convacc(psdToAcc,'G''s','m/s^2');
For more information, refer the following link.
  2 Comments
Nguyen Trieu
Nguyen Trieu on 21 Apr 2020
I am trying to examinate how the fusion function works with the example "Estimating Orientation Using Inertial Sensor Fusion and MPU-9250" and not be able to figure out this one part of the code where the noise of the acceleration is assigned to the value of: 0.0061m/s^2.
% GyroscopeNoise and AccelerometerNoise is determined from datasheet.
GyroscopeNoiseMPU9250 = 3.0462e-06; % GyroscopeNoise (variance value) in units of rad/s
AccelerometerNoiseMPU9250 = 0.0061; % AccelerometerNoise(variance value)in units of m/s^2
viewer = HelperOrientationViewer('Title',{'AHRS Filter'});
FUSE = ahrsfilter('SampleRate',imu.SampleRate, 'GyroscopeNoise',GyroscopeNoiseMPU9250,'AccelerometerNoise',AccelerometerNoiseMPU9250);
stopTimer
I have tried to look through the datasheet of MPU-9250 and wondering wheter or not the Noise Power Spectral Density with the value of 300µg/√Hz to be converted into the 0.0061m/s^2 above? I have tried to work with 300µg/√Hz with the code you have suggested but it doesn't return the value of 0.0061m/s^2 as above.
Nguyen Trieu
Nguyen Trieu on 21 Apr 2020
Edited: Nguyen Trieu on 21 Apr 2020
The script I used is:
psd = 300*1e-6;
w = 2*pi*10; % f is in Hz(I believe it is 10 Hz according to the MPU-9250 datasheet).
psdToAcc = psd*sqrt(w); % Converting psd to acceleration unit 'g'
gTomps2 = convacc(psdToAcc,'G''s','m/s^2');

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