PsiMA1 produces a first order moving average time series with mean mean, volatility volatility, moving average coefficient coef1 and initial error term err0. 

This is a well known and used time series due to its simplicity and ease of use.  The PsiMA1 time series is depicted by an autocorrelation function (ACF) that reduces to 0 after lag 1 and a partial autocorrelation function (PACF) that decreases geometrically. 

For more information, see the Analytic Solver Reference Guide downloadable from Analytic Solver by clicking Help -- User Guides -- Analytic Solver Reference Guide.