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Full-Text Articles in Physical Sciences and Mathematics

Refining Environmental Satellite Data Using A Statistical Approach, Md Zahidur Rahman, Leonid Roytman, Abdelhamid Kadik Apr 2013

Refining Environmental Satellite Data Using A Statistical Approach, Md Zahidur Rahman, Leonid Roytman, Abdelhamid Kadik

Publications and Research

The proposed approach in this article applies an efficient and novel statistical technique to accurately describe radiometric data measured by Advanced Very High Resolution Radiometers (AVHRR) onboard the National Oceanic and Atmospheric Administration’s (NOAA) Polar Orbiting Environmental Satellites (POES). The corrected data set will then be applied to improve the strength of NOAA Global Vegetation Index (GVI) data set for the 1982- 2003 period produced from AVHRR. The GVI is used extensively for studying and monitoring land surface, atmosphere and recently for analyzing climate and environmental changes. The POES AVHRR data, though useful, cannot be directly used in climate change …


Optimal Control Of Katabatic Flows Within Canopies, Hongbin Chen, Chuixiang Yi Jul 2012

Optimal Control Of Katabatic Flows Within Canopies, Hongbin Chen, Chuixiang Yi

Publications and Research

What slope angle favours the development of katabatic flow is still an open question. Some studies have clarified that katabatic winds are stronger on steep slopes, while others have demonstrated that katabatic winds are stronger on gentle slopes. Here, we explore the control mechanisms of katabatic flow using a simplified theoretical model in an attempt to clarify the causes of the paradoxical findings. Our results indicate that optimal conditions for katabatic flows within canopies are synergistically controlled by terrain angle, canopy structure and thermal condition through a simple equation:

LcVT-2 sin3 α = b,

where …


A Statistical Method To Correct Radiometric Data Measured By Avhrr Onboard The National Oceanic And Atmospheric Administration (Noaa) Polar Orbiting Environmental Satellites (Poes), Md Zahidur Rahman, Leonid Roytman, Abdelhamid Kadik May 2011

A Statistical Method To Correct Radiometric Data Measured By Avhrr Onboard The National Oceanic And Atmospheric Administration (Noaa) Polar Orbiting Environmental Satellites (Poes), Md Zahidur Rahman, Leonid Roytman, Abdelhamid Kadik

Publications and Research

This paper apply an statistical technique to correct radiometric data measured by Advanced Very High Resolution Radiometers(AVHRR) onboard the National Oceanic and Atmospheric Administration (NOAA) Polar Orbiting Environmental Satellites(POES). This paper study Normalized Difference Vegetation Index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data for the period 1982-2003. AVHRR weekly data for the five NOAA afternoon satellites NOAA-7, NOAA-9, NOAA-11, NOAA-14, and NOAA-16 are used for the China dataset, for it includes a wide variety or different ecosystems represented globally. GVI has found wide use for studying and monitoring land surface, atmosphere, and recently for analyzing climate and …


The Most Effective Statistical Approach To Correct Environmental Satellite Data, Md Zahidur Rahman, Leonid Roytman Jan 2009

The Most Effective Statistical Approach To Correct Environmental Satellite Data, Md Zahidur Rahman, Leonid Roytman

Publications and Research

The proposed paper apply novel statistical approach to correct radiometric data measured by Advanced Very High Resolution Radiometers (AVHRR) onboard the National Oceanic and Atmospheric Administration (NOAA) Polar Orbiting Environmental Satellites (POES). This paper investigates Normalized Difference Vegetation Index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003. AVHRR weekly data for the five NOAA afternoon satellites for the China dataset is studied, for it includes a wide variety of different ecosystems represented globally. It was found that data for the years 1988, 1992, 1993, 1994, 1995 and 2000 are not stable enough compared to other years …


Removing Long-Term Errors From The Avhrr Observation Based On Normalized Difference Vegetation Index (Ndvi), Md Zahidur Rahman, Leonid Roytman, Atiqur Rahman, Felix Kogan, Runa Jesmin Jan 2008

Removing Long-Term Errors From The Avhrr Observation Based On Normalized Difference Vegetation Index (Ndvi), Md Zahidur Rahman, Leonid Roytman, Atiqur Rahman, Felix Kogan, Runa Jesmin

Publications and Research

This paper investigates Normalized Difference Vegetation Index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003. Advanced Very High Resolution Radiometer (AVHRR) weekly data for the five NOAA afternoon satellites for the China dataset is studied, for it includes a wide variety of different ecosystems represented globally. It was found that data for the years 1988, 1992, 1993, 1994, 1995 and 2000 are not stable enough compared to other years because of satellite orbit drift, and AVHRR sensor degradation. It is assumed that data from NOAA-7 (1982, 1983), NOAA-9 (1985, 1986), NOAA-11 (1989, 1990), NOAA-14 (1996, 1997), …