Generation of cloud free image from NOAA AVHRR data
Tsukasa Hosomura*, Haruhisa Shimoda and Toshibumi Sakata
Tokai University Research & Information Center
Tomogaya 2-28-4, Shibuya-ku, Tokyo 151, Japan
*AIT/Division of Computer Science
G.P.O Box 2754, Bankok 10510, Thailand
Introduction
This paper describes about some methods for generation of cloud free image from NOAA AVHRR data. Target area of this study is large paddy fields spreading over Hua Zhong and Hua Nan area, i.e. basin of yang Zi river. This are has a regional scale and it is very difficult to get ground informations in a timely manner. NOAA AVHRR data is optimal for such monitorings. In this study, a system in order to obtain the necessary informations of paddies in this area within certain time interval by using NOAA AVHRR are examined.
This system is composed of the following steps. NOAA AVHRR images are connected in Tokai university Space Information Centre (TSIC) in Kumamoto, Japan. These data re transported to Tokai University Research & Information Center (TRIC) in Tokyo and processed there. Data processing are composed of two steps. First step is preprocessing which include geometric corrections and readiometric correction. Geometric corrections were conducted to precisely co-register each images. Radiometric corrections were performed to eliminate the radiometric distortions mainly caused by incidence angle difference of sub light. In the second step, a cloud free image of the target area was generated by combining images within one or two weeks.
Image data used in this study
Test image data
Test image data used in this study are as follows :
|
DATA 1 | NOAA AVHRR
1988.MAY.15.AM.8:43, NPOAA-10
|
| DATA 2 | NOAA AVHRR
1988.MAY.18 PM. 16:52, NOAA-9 |
A NOAA image of the target area is show in fig. 1 and fig. 2 target area of this study is Hua Zhong and Hua Nan area, i.e basin of Yang Zi river.
Fig. 1 NOAA AVHRR Image 1
(1988.5.15. AM. 8:43)
Fig. 2 NOAA AVHRR Image 2
(1988.5.18. PM. 16:52)
