Sensor head performance, responsivity and NETD using pyroelectric linear arrays

The use of linear pyroelectric arrays in IR sensor heads in which the scene is panned across, or traverses, the array was analyzed, using an array structure consisting of a pyroelectric wafer, a bonding layer and a substrate. The responsivity of the array for a moving radiation pattern, the responsivity corrected by the amplifier for the fall with temporal frequency, the integrated noise in the bandwidth, and noise equivalent temperature difference (NETD) were calculated. Typical values were plotted against the spatial frequency of the radiation pattern. Variations with image speed and with the angle of the pattern to the direction of movement are shown. The performance is attractive for a number of applications, with NETD values in the region of 0.1 to 0.3 C where a moderate bandwidth applies. However, at low frequencies imposed by slow image speeds, the need for reticulation is demonstrated.