Abstract
This chapter deals with several fundamental properties of electromagnetic radiation. We first define the basic notions of radiometry, namely, the physical quantities associated with the energy transported by electromagnetic radiation. Those photometric quantities and units related to lighting techniques, photography, and so on, are all adapted to the sensitivities of the human eye. This means that they refer to visible wavelengths, and thus are not suitable for astronomical observations, which cover the whole electromagnetic spectrum and must therefore be independent of the properties of the human eye.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
A more detailed discussion of these classic issues can be found, for example, in Stars and Stellar Systems, Vol. II, Astronomical Techniques. A more recent and very complete reference can be found at the website www.astro.virginia.edu/class/oconnell/astr511/lec14-f03.pdf (University of Virginia, USA).
- 2.
The Sun is considered as a standard in the visible, but its spectral intensity fluctuates, in particular at radio and X-ray wavelengths. Even at visible wavelengths, at the time of writing (2007), more and more accurate measurements are required to analyse the possible impact of solar fluctuations on climate change.
- 3.
Synchrotron radiation is described in Astrophysical Formulae, Sect. 1.25.
- 4.
A complete set of references concerning the extraordinary COBE mission is given by Mather J.C., Infrared measurements from the Cosmic Background Explorer, Infrared Phys. Technol. 35, 331–336, 1994.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2012 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Léna, P., Rouan, D., Lebrun, F., Mignard, F., Pelat, D. (2012). Radiation and Photometry. In: Observational Astrophysics. Astronomy and Astrophysics Library. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-21815-6_3
Download citation
DOI: https://doi.org/10.1007/978-3-642-21815-6_3
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-21814-9
Online ISBN: 978-3-642-21815-6
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)