ABSTRACT

The Markov chain canopy reflectance model (MCRM) by Kuusk (1995b) has been tested versus the ray tracing model on two different computer maquettes of field crops (Barley and Beet), and on the field data collected in the frame of the Franco-English Collaborative Reflectance Experiment in 1989 and 1990 on sugar beet plots. Separate comparisons of single and multiple scattering components of the MCRM and the ray tracing procedure demonstrated good agreement of the models. Inversion of the MCRM on field data returned good estimates of LAI in the range LAI = 0.1-4 using nadir reflectance data in 3 SPOT and 2 Landsat TM channels. The estimated chlorophyll content was well correlated to the measured one, although underestimated to some extent. The use of directional data at 45° zenith angle and four azimuth angles improved the estimates of both the LAI and the chlorophyll content. It allowed also to estimate additional parameters of the canopy structure (leaf size, LAD, the Markov parameter).

The correspondig author is:

Andres Kuusk
Tartu Observatory
EE2444 Tőravere
Estonia
Phone:   372 - 7 - 410 152
Fax:     372 - 7 - 410 205
E-mail:  andres@aai.ee