Sensor-to-Sensor Identi cation for the SOFIA Testbed

In many system identi cation applications, only output measurements are available for constructing empirical models. In these cases, sensor-to-sensor identi cation (S2SID) can be used. In the SISO case, one measurement is designated as the pseudo-input, while another measurement is designated as the pseudo-output. Identi cation between the pseudoinput and pseudo-output results in the construction of a pseudo transfer function (PTF). In the present paper we apply S2SID to data obtained from the NASA SOFIA (Stratospheric Observatory for Infrared Astronomy) testbed. The objective of this work is to determine whether linear PTF models can approximate the relationship between di erent sensor measurements. The identi cation of such models can potentially be used in practice to detect faults or changes in a structure.