Adding noise with certain standard deviation to uncorrupted data

Hello,

I have a 1-D data set and I want to artificially corrupt it with noise of a certain standard deviation. Say for accurate pitch rate measurements 'q' of an aircraft, I want to add noise with a std. of 0.1047 rad/sec. How do I proceed?

Regards,

Answer 1

[Wayne King]

when you say 0.1047 rad/second, do you want these values to be bounded by a certain interval? or is the frequency value continuous (I'm assuming it is by rad/sec)

The other question is what probability distribution do you want the noise to follow and what is the mean value?

I'll assume here: Gaussian, mean 0, std 0.1047, frequency continuous

noise = 0.1047*randn(1000,1);  % gives you 1000 samples

Note you get negative and positive rad/second values -- that may very well not be what you want.

Answer 2

[Jos (10584)]

In addition to Wayne's suggestion you can sample noise from any distribution with unknown parameters and set the standard deviation to a specific value:

DesiredSD = 0.1047 ;                               % the desired standard deviation
noise = random('ncx2',10*rand,10*rand,[1000 1]) ;  % some random noise
noise = DesiredSD * (noise ./ std(noise)) ;        % scale the standard deviation
std(noise)                                         % voila!