Conversion of nadir, narrowband reflectance in red and near-infrared channels to hemispherical surface albedo
✍ Scribed by Mick J. Russell; Manuel Nunez; Mark A. Chladil; Jose A. Valiente; Ernesto Lopez-Baeza
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 941 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0034-4257
No coin nor oath required. For personal study only.
✦ Synopsis
M easured nadir-viewed narrow-band rejectances in red and near infrared channels simulating AVHRR Channels 1 and 2 are compared with measured integrated solar spectrum hemispherical albedos. Rejectances and albedos were measured from an aircraft over four widely diferent vegetation surfaces in southeastern Tasmania (Australia). A linear function is used to simultaneously correct for narrow band to broad band conversion errors and to convert nadir viewed reflectances to hemispherical albedos. While the application of the conversion equation presented is limited to the vegetation types of the study, the equation is independent of vegetation type. Results indicate that the rejectance from the rough surface of a forest canopy is not Lambertian and that the use of a directional to hemispherical albedo conversion using a Lambertian assumption may lead to errors as great as 35%.