The content in this Field Guide starts with traditional illumination in imaging systems, followed by the recent advances in computer-aided design of high efficiency nonimaging illumination optics, along with the modern source models that support these techniques. Sections on the illumination of visual displays are included as well as some important topics on architectural illumination.

Field Guide to Illumination

In conjunction with the development of a bidirectional scattering metrology project, a large number of papers pertaining to the theory and measurement of bidirectional scattering from optical surfaces were collected and categorized. This collection includes papers that deal with various aspects of the bidirectional scattering distribution function (BSDF), its measurement, interpretation, use, and implications. Each paper is classified in one or more subject categories on the basis of its technical content. The subject categories are included just to serve as a key to the most salient characteristics of each paper cited. Because of the interest in this field, this bibliography is being published as a service to the public.

/pdf/bidirectional-scattering-distribution-function-bsdf-a-418hurcg4u.pdf

Bidirectional Scattering Distribution Function (BSDF): A Systematized Bibliography.

We discuss errors and uncertainties in calibrating infrared radiometers to measure the temperature of clouds in the earth's atmosphere. Many of the points we make apply to any radiometric
temperature-sensing application where the target temperature is less than the ambient temperature. Dominant uncertainties and errors are due to ambient radiance reflected from the blackbody-simulator source, thermal fluctuations in the radiometer, and imprecise voltage measurements. Our improved technique removes, reduces, or accounts for these errors and uncertainties. The resulting calibration uncertainty is ± 0.8°C for a radiometer with a 10-v output range. We verified this accuracy by comparing cloud-base temperatures measured by ground-based IR radiometers, in situ (radiosonde) sensors, and other remote sensors on the ground and on satellites. We made these comparisons for spatially uniform blackbody clouds that filled the field of view of our ground-based radiometers.

Improved calibration of infrared radiometers for cloud temperature remote sensing

Pixel-by-pixel rectification of urban perspective thermography

Radiometry of optical systems with quasi-homogeneous sources: A linear systems approach

Etude du concept d'angle solide projete en radiometrie. Differences entre les notions d'angle solide et d'angle solide projete pouvant conduire a des erreurs dans la theorie des corps noirs artificiels

Projected solid angle and blackbody simulators.

Four references and two arrangements are described for cavity emissivities greater than one. There are different types of emissivities, but all depend on a radiometric output divided by what that output would have been if it had come from an ideal blackbody. Cavity emissivities can be greater than one for a nonisothermal cavity when the temperature of the reference blackbody is selected to have a lower value than the temperature of most of the cavity wall surface.

Cavity Emissivities Greater Than One

Misunderstandings are described concerning blackbodies, simulators, cavities and apertures. Blackbodies are identified as ideal (not real) items, while the expression blackbody simulator is recommended for real (not ideal) approximations to blackbodies. Surface and volume considerations for blackbodies and blackbody simulators are addressed. Blackbody and blackbody simulator history are traced. The important roles of blackbody simulator cavities and blackbody simulator apertures are emphasized. 0. INTRODUCTION In agreement with the title, this paper discusses several variations of the expressions blackbody and blackbody simulator. In agreement with an implication of the title, this paper addresses the proposition thatthere are widespread misunderstandings concerning blackbodies, simulators, cavities and apertures.This paper is divided into six parts: (1) Blackbodies and blackbody simulators; (2) Blackbody surfacesand blackbody volumes; (3) Blackbody and blackbody simulator history; (4) Blackbody simulator cavities and

A Blackbody, A Blackbody Simulator, A Blackbody Simulator Cavity, A Blackbody Simulator Cavity Aperture, And A Blackbody Simulator Aperture Are Each Different From One Another

Three types of cavity emissivities are described based on wavelength, two types based on temperature, and five types based on geometry. Nonisothermal cavities are shown to be best represented by a two-temperature emissivity while most other items, including isothermal cavities, are customarily represented by a one-temperature emissivity. Radiance based emissivity and local hemispherical emissivity are recommended for making cavity evaluations and comparisons, while the hemispherical emissivity of the cavity aperture and a cavity emissivity that is based on detector considerations are shown to be faulty.

A Mess Of Cavity Emissivities

The concept of T* is introduced as a special kind of average foreground temperature. It is shown that weighting for this average depends on the projected solid angle of different items as seen from the measurement target. It is shown that T* considerations are important for most radiometric measurement tasks. The relationships among radiometry, cavity radiation theory, and T* are shown.

Frederick O. Bartell

Papers

Projected solid angle and blackbody simulators.

Cavity Emissivities Greater Than One

A Blackbody, A Blackbody Simulator, A Blackbody Simulator Cavity, A Blackbody Simulator Cavity Aperture, And A Blackbody Simulator Aperture Are Each Different From One Another

A Mess Of Cavity Emissivities

T*: a calculation aid for radiometry