Estimation of daily-integrated PAR from sparse satellite observations: comparison of temporal scaling methods
Source: International Journal of Remote Sensing, Volume 31, Number 6, 2010 , pp. 1661-1677(17)
Publisher: Taylor and Francis Ltd
Abstract:Incident Photosynthetically Active Radiation (PAR) is a critical parameter for modelling ecosystem productivity. An algorithm for estimating instantaneous PAR from Moderate Resolution Imaging Spectroradiometer (MODIS) data was developed earlier; however, daily-integrated PAR is more meaningful than instantaneous PAR in many cases because many land surface models require a daily or coarser temporal resolution. This paper compares two different algorithms (adjusted sinusoidal interpolation and look-up table) for estimating daily-integrated PAR from instantaneous PAR values. Statistical analysis of the validation results indicates that the look-up table method more accurately estimates daily-integrated PAR than the use of adjusted sinusoidal interpolation. We also investigated how window size, daytime length and the number of overpass counts per day affect bias and the relative error of estimation. Validation using field measurements, and comparison with the Geostationary Operational Environmental Satellites PAR product, demonstrates that data collected by MODIS can be used to provide reliable estimates of daily-integrated PAR.
Document Type: Research Article
Affiliations: 1: Department of Geography, University of Maryland, College Park, MD, USA 2: The State Key Laboratory of Resources and Environmental Information System, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China 3: Department of Geography, Central Michigan University, Mount Pleasant, MI, USA
Publication date: February 1, 2010