Share Email Print

Optical Engineering

Imaging system performance based upon Fλ/d
Author(s): Gerald C. Holst
Format Member Price Non-Member Price
PDF $20.00 $25.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Imaging system performance can be described in the spatial domain, where the optical blur diameter is compared to the detector size, or in the frequency domain [modular transfer function (MTF) approach], where the optics cutoff is compared to the detector cutoff. Both comparisons provide a metric that is a function of Fλ/d, where F is the focal ratio, λ is the wavelength, and d is the detector size. Fλ/d is applied to three models: Schade's equivalent resolution (visible systems), Snyder's MTFA (MTF area; visible systems), and target acquisition (NVThermIP—an infrared system model). All models produced curves that exhibit a transition in the region 0.41<Fλ/d<1.0, representing a change from detector-limited to optics-limited performance. NVThermIP's contrast equations are simplified to easily calculate resolution and acquisition range. Trade-off analyses include range versus detector size, versus focal ratio, and versus field of view (FOV). When Fλ/d<2, no aliasing occurs. This may be important for medical imaging, where sampling artifacts may be interpreted as a medical abnormality, or for space probes, where it is impossible to obtain ground truth.

Paper Details

Date Published: 1 October 2007
PDF: 10 pages
Opt. Eng. 46(10) 103204 doi: 10.1117/1.2790066
Published in: Optical Engineering Volume 46, Issue 10
Show Author Affiliations
Gerald C. Holst, JCD Publishing (United States)

© SPIE. Terms of Use
Back to Top