UCLA Extension

Infrared Imaging: Applications and Subsystems

The use of infrared imaging systems is expanding rapidly in military, commercial, and civil applications, such as surveillance, thermal imaging and thermographics, targeting and homing, track-and-search, and multispectral/hyperspectral reflective and emissive infrared imaging. Key enabling infrared imaging sensor subsystems include advanced focal planes and signal processing, cryogenics, calibration, and advanced infrared optics. Advances in component technologies enable increased user flexibility, better performance, greater ease-of-use, and affordable costs, and promise continuing expansion of the infrared imaging field.

This course is intended for scientists, engineers, systems managers, and other professionals who design and use infrared imaging systems in a variety of applications.

Course Goals

  • Appreciate a systems-oriented, top-down approach to selecting and configuring IR systems
  • Describe a wide variety of infrared imaging instrument designs and implementations and applications, including broadband, multispectral, and hyperspectral infrared imagers
  • Understand the fundamentals of infrared system performance figures-of-merit
  • Understand first-order optical system design, performance, and sizing in IR imager system design
  • Compare the technical merits and performance characteristics of various infrared detector materials and CMOS focal plane readout designs
  • Understand infrared imaging system drivers and trades
  • Understand the objectives of IR imager calibration
  • Describe the key scene and sensor-dependent sources of calibration error
  • Review calibration source hardware
  • Understand differences between relative and absolute calibration, including spectral effects
  • Calculate subsystem requirements via a flowdown process using several specific IR imager examples: multispectral pushbroom and whiskbroom imagers, reflective slit scanning hyperspectral imagers (aircraft and space-based), and a point source detection system
  • Compute focal plane and optical system heat loads
  • Understand cryogenic cooling systems, including mass and power scaling laws
  • Understand the state of the art in cryocooler technology

Coordinator and Lecturer

Terrence S. Lomheim, PhD, Distinguished Engineer, Sensor Systems Subdivision, The Aerospace Corporation, El Segundo, California. For the past 34 years at The Aerospace Corporation, Dr. Lomheim has held both technical staff and management positions. He has performed detailed experimental evaluations of the electro-optical properties, imaging capabilities, and radiation-effects sensitivities of infrared and visible focal plane devices, and has been involved in the development of modeling tools used to predict instrument-level performance for advanced DoD visible and infrared point-source and imaging sensor systems. Dr. Lomheim has authored and coauthored 61 publications in the areas of visible and infrared focal plane technology, sensor design and performance, and applied optics. He is the co-author (with Gerald C. Holst) of CMOS/CCD Sensors and Camera Systems, Second Edition, JCD Publishing and SPIE Press, 2011. He also is a part-time instructor in the physics department at California State University, Dominguez Hills, and regularly teaches technical short courses for the International Society for Optical Engineering (SPIE) and for the UCSB and UCLA Extension programs. He is a Fellow of SPIE.

Daily Schedule

Day 1

Infrared Systems and Applications

  • Overview of infrared system applications
    —Industrial/commercial/DoD/civil
  • Infrared imager deployment modes
    —Lab-based, industrial work-site, mobile, aircraft/space-based, ground vehicle, missile seeker/smart weapon

IR System Design Fundamentals

  • Overview of the basics of infrared radiometry
    —Quantities, definitions, nomenclature
  • Signal/photon detection and transducing
  • Overview of the basics and theory of noise including photon noise
  • System noise components and noise modeling

IR Optical System Design Basics

  • Overview of basic optical concepts
  • Lateral magnification, instantaneous field-of-view, field-of-view, f-number, effective focal length and aperture
  • Modulation transfer function: optical system, detector effects, smear, composite, polychromatic
  • Optical system design forms based on f# and field-of-view
  • Mass and volume scaling

IR System Design Implementations

  • Infrared imager implementations
    —Thermal and reflective bands
    —Panchromatic, multispectral, hyperspectral, ultraspectral imaging—Point-source detection and tracking
  • Infrared instrument design types
    —IR imaging cameras/scanners/starers
    —IR imaging spectrometers: multiband line scanners, filter wheels, dispersive prism, dispersive grating, wedge, and Fourier-transform imagers with 2D arrays

IR System Performance Metrics and Characteristics

  • Instrument performance measures and metrics
    —Noise-equivalent figures-of-merit
    —NE-deltaT, NE-delta rho, NESR, NET, System D-star
    —NEI, NEE, NEV, NEDN
  • Acquisition range
  • Transition from point to extended target viewing
  • Dynamic range
  • Uniformity: gain/offset
  • Clutter noise for point-source systems
  • Design flowdown block diagrams

Day 2

IR Focal Planes and Signal Processing

  • Detector basics
  • Detector arrays formats, photovoltaic versus photovoltaic, cut-off wavelength, operating temperature, D-star
  • Focal plane detectors: HgCdTe, InSb, InGaAs, quantum well, Schotty-barrier doped-silicon, microbolometer
  • D-star-based comparison of detector spectral and thermal performance
  • CMOS readouts: survey of unit cell circuits, noise effects, performance, AC and DC injection efficiency, on-chip versus off-chip analog-to-digital conversion, video signal chains, power dissipation

IR System: Illustration of the Key Drivers in the Selection of Focal Plane Technology

  • Matrix of top-level applications with rationale for choice of focal plane type

Infrared System Calibration

  • Mission and system goals of calibration
  • Calibration basics: accuracy vs. precision, absolute vs. relative error, radiometric cal, spectral cal, geometrical cal, fixed pattern correction
  • Calibration sources: natural, artificial, traceability to a primary standard
  • Knowledge: spatial, spectral, and temporal
  • Radiometric calibration
    —Instrument and laboratory sources
    —Sensor errors that impact calibration: temporal drift, nonlinearity, noise, near-field radiance estimation, off-axis rejection, contamination, spectral response, polarization, pixel registration
  • Measurement and characterization methodologies

Cryogenic Cooling of Infrared System

  • Computing focal plane heat loads
  • Electrical and lead parasitic, conduction and radiation from supports, optics and radiation shields, environmental loads
  • Highlights of cryogenic cooling systems
    —Cryostat, thermoelectric, passive radiators
    —Mechanical refrigerators (cryocoolers)—Scaling rules for various cooling methods
  • Characteristics, mass and power penalties, suitability to various applications

IR System Design Examples

  • Reflective VNIR/SWIR multispectral pushbroom scanner
  • Aircraft-based LWIR slit scanning dispersive hyperspectral scanner
  • Low-earth orbit visible/infrared whiskbroom scanning radiometer
  • Geosynchronous infrared point-source detection system
  • Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS)
  • Space-based VNIR/SWIR, MWIR, LWIR hyperspectral design synthesis: point design, interaction of performance and design features, methodology for design optimization

For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu | (310) 825-3344 | fax (310) 206-2815

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