Page 1 of 4 The peak stability metric is sometimes called a jitter metric. It measures the peaktopeak change in attitude in any interval of time of width T seconds. This is illustrated in the first figure to the right. The peaktopeak change in attitude is given by the equation
Δ_{p}(t) = max_{ τ in [0,T]}  Θ(t) – Θ(t – τ) 
The peak stability metric is given by the equation
Δ_{p} = max_{ t in [–∞,∞]} (Δ_{p}(t))
The peak stability metric is highly conservative because infrequent and rapid transient attitude motions are generally inconsequential to payload performance. The infrequent nature of large transients has lead to the use of a meansquare peakstability metric. The meansquare peaktopeak attitude change is defined by
σ^{2}_{ps} = E{(Δ_{p}(t))^{2}}
The peak stability metric and the meansquare peak stability metric require significant computation to analyze, particularly for long data records. There is also the question of how small the discrete steps in τ need to be to find the peaktopeak change in attitude. Because these stability metrics are nonlinear, they have no mathematical equivalent in the frequency domain.
