Improving light and heat spectra measurements

October 30, 2013

Whether you want to investigate objects in space, characterize the quality of light sources, optimize photovoltaics modules or analyze chemical compounds, measuring the spectrum of light- or heat sources is often the method of choice. Conventional procedures thereby generate radiation distribution curves which are distorted and have to be subsequently corrected. The Physikalisch-Technische Bundesanstalt (PTB) has now developed a mathematical procedure which yields clearly improved results and can be applied in numerous fields of radiometry and photometry. The software required can be downloaded free of charge from PTB's website.

Measuring systems for optical or such as, e.g., radiometers, spectrometers and photometers, generate spectral distribution curves which shed light on the characteristics of the measured radiation (e.g. its luminance, its colour quality, its temperature or its wavelength). These distribution curves, however, exhibit distortions which are caused by the measuring instrument used. There are correction procedures, but these are reliable to a certain extent only. Scientists at PTB have found a new approach to this problem: they have, for the first time, considered the occurring distortions as mathematical convolution and used the Richardson-Lucy method - an iterative procedure - for the deconvolution.

An issue which has often been discussed with regard to the Richardson-Lucy method is the need for a criterion for the breaking of the iterations. In this context, a novel approach has been developed at PTB which works, in principle, automatically and independent of additional parameters. This new approach has turned out to be very robust, both in comprehensive simulations and in investigations of measurement data. The scientists hereby investigated numerous scenarios with diverse line spread functions and signal-to-noise ratios. The procedure developed in this way is suitable both to improve broadband spectral distribution curves (as occurring, e.g., in heat radiators) and narrowband distribution curves (as occurring in LEDs).

Explore further: Checking people at airports -- with terahertz radiation

More information: Eichstädt, S. (2013). Comparison of the Richardson-Lucy method and a classical approach for spectrometer bandpass correction, Metrologia 50, 107 - 118.

Related Stories

Checking people at airports -- with terahertz radiation

September 18, 2008

Within the last few years the number of transport checks – above all at airports – has been increased considerably. A worthwhile effort as, after all, it concerns the protection of passengers. Possibilities for new and ...

X-ray telescope to detect dark energy in space

March 16, 2010

It will be on board in 2012, when a Soyus-2 rocket carries an X-ray telescope into space to decode the nature of the universe's dark energy: an X-ray detector developed by the Max Planck Institute for Extraterrestrial Physics. ...

Seeing in the dark

October 29, 2013

Thermal infrared (IR) energy is emitted from all things that have a temperature greater than absolute zero. Human eyes, primarily sensitive to shorter wavelength visible light, are unable to detect or differentiate between ...

Recommended for you

Magnetism at nanoscale

August 3, 2015

As the demand grows for ever smaller, smarter electronics, so does the demand for understanding materials' behavior at ever smaller scales. Physicists at the U.S. Department of Energy's Ames Laboratory are building a unique ...

Study calculates the speed of ice formation

August 3, 2015

Researchers at Princeton University have for the first time directly calculated the rate at which water crystallizes into ice in a realistic computer model of water molecules. The simulations, which were carried out on supercomputers, ...

Small tilt in magnets makes them viable memory chips

August 3, 2015

University of California, Berkeley, researchers have discovered a new way to switch the polarization of nanomagnets, paving the way for high-density storage to move from hard disks onto integrated circuits.

Scientists bring order, and color, to microparticles

August 3, 2015

A team of New York University scientists has developed a technique that prompts microparticles to form ordered structures in a variety of materials. The advance, which appears in the Journal of the American Chemical Society ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.