Hi all,

I was trying to model an example in the aircraft tracking and assumed the signals are noisy with normal distribution but for an error in my code, when I generated the noise with rnorm I got NAN in the SD.

sigma.eps1<- sqrt(1000)

sd(rnorm(0,1,sigma.eps1))

NA

So any idea why I got this error, sorry if my code is not clear. Thankyou.

Best regards,

Lamia