Nonuniformity correction and restoration of passive millimeter-wave images

Alan H. Lettington; Sophie Tzimopoulou; Malcolm P. Rollason

doi:10.1117/1.1339875

1 February 2001 Nonuniformity correction and restoration of passive millimeter-wave images

Alan H. Lettington, Sophie Tzimopoulou, Malcolm P. Rollason

Optical Engineering, Vol. 40, Issue 2, (February 2001). https://doi.org/10.1117/1.1339875

We discuss methods of improving the quality and resolution of passive millimeter-wave images, particularly those obtained using the Defense Evaluation and Research Agency (DERA) MITRE imager and the more recent MERIT imager. This later real time imager consists of some novel optics followed by a conical scanner in the form of a disk rotating about an axis through its center and tilted with respect to its normal. A horizontal array of receivers is scanned such that each receiver performs a conical scan pattern in the scene. The resulting image, which has a 40x20 deg field of view, consists of a series of circles whose centers are uniformly displaced horizontally. Each receiver is calibrated initially using a two point correction but then drifts in time and a scene based correction is applied. Following preprocessing the images are superresolved using nonlinear restoration techniques. Two such techniques are described. The first is an error energy reduction algorithm that uses background subtraction and the second assumes a Lorentzian distribution of gradients within an image. Both are able to superresolve without significantly enhancing the noise. These various processes are described and images presented.

©(2001) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Alan H. Lettington, Sophie Tzimopoulou, and Malcolm P. Rollason "Nonuniformity correction and restoration of passive millimeter-wave images," Optical Engineering 40(2), (1 February 2001). https://doi.org/10.1117/1.1339875

Published: 1 February 2001

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

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.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available