| Abstract: | The spectral ratio method is based on the concept that although the spectral radiances are very sensitive to small changes in temperature the ratios are not. Only an approximate estimate of temperature is required thus, for example, we can determine the emissivity ratio to an accuracy of 1% with a temperature estimate that is only accurate to 12.5 K. Selecting the maximum value of the channel brightness temperatures is an unbiased estimate. Laboratory and field spectral data are easily converted into spectral ratio plots. The ratio method is limited by system signal:noise and spectral band-width. The images can appear quite noisy because ratios enhance high frequencies and may require spatial filtering. Atmospheric effects tend to rescale the ratios and require using an atmospheric model or a calibration site. ?? 1992. |
| Genre: | Article |
| ProdID: | 70017051 |
| Citation Author: | Watson, K. |
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| Citation End Page: | 116 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Remote Sensing of Environment |
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| Citation Number Of Pages: | 4 |
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| Citation Search Results Text: | Spectral ratio method for measuring emissivity; 1992; Article; Journal; Remote Sensing of Environment; Watson, K. |
| Citation Start Page: | 113 |
| Citation Volume: | 42 |
| Citation Year: | 1992 |
| Type: | citation/reference |
| Text: | Spectral ratio method for measuring emissivity; 1992; Article; Journal; Remote Sensing of Environment; Watson, K. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 1 Jan 1992 00:00 -0600 |
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