Analog methods to deal with the nonuniformity correction problem for infrared focal plane arrays have been addressed. On-chip neural-network based techniques and simulation results of these schemes are presented. The approach is based on one in which the nonuniformity correction of individual pixels in accomplished by the method of steepest descent and its well known special case, the least-mean-square method (LMS). Alternative learning methods can be derived from the LMS method by considering only sign of the data or sign of the error. These nonlinear versions of the LMS methods have potential hardware implementation benefits such as power dissipation and simplicity. The simulation results of the nonlinear learning algorithm along with the LMS algorithm results are presented. Analog circuit elements implementing these learning algorithms are also presented. Our simulation results are very useful in that they model the nonidealities that are associated with specific hardware circuit implementation. These include the nonlinearities, scalar multiplicative error and offsets of both feedback multipliers and the integrators. The nonideal factors that cause instability and performance degradation in learning are multiplier and integrator offsets. These factors are shown to be much more important in the pixel offset correction than in the gain correction.
Proceedings Volume Editor (2)
This will count as one of your downloads.
You will have access to both the presentation and article (if available).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.