Cloud detection method by using MODIS remote sensing thermal infrared data

A cloud detection and thermal infrared technology, applied in the field of cloud detection, can solve the problem of not being able to detect very stably

CN103439757AInactive Publication Date: 2013-12-11海全胜
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2013-12-11
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a cloud detection method by using MODIS remote sensing thermal infrared data, which involves mainly utilizing the emissivity difference between a cloud and an underlay object in a MODIS data long wave radiated wave band for cloud detection. Since the cloud is different from such underlay objects as vegetation, exposed soil, snow, sand, water area and the like in terms of substance properties and surface conditions, their emissivity in a long wave band are different. The invention further provides a cloud index (TCDI) method which involves cloud detection by using the emissivity difference between the cloud and other underlay objects, is free from the influence of sunlight, and is capable of the cloud detection in both the day time and at night.
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Description

technical field

[0001] The invention relates to the field of cloud detection, in particular to a cloud detection method utilizing MODIS remote sensing thermal infrared data. Background technique

[0002] At present, cloud detection is mostly based on the difference in reflectivity or radiation brightness temperature between clouds and underlying objects such as vegetation, soil, snow, and water. However, the reflectivity of ground objects is affected by factors such as the sun's altitude angle, azimuth angle, and sunshine time, so it can only detect clouds during the day; in addition, the radiation brightness temperature of clouds, vegetation, soil, snow and other background objects also varies greatly with temperature. Therefore, neither the albedo nor the radiation brightness temperature can be used to detect the 24-hour cloud stably. Contents of the invention

[0003] The object of the present invention is to provide a cloud detection method using MODIS remote sensing ...

Examples

Embodiment Construction

[0027] The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

[0028] The invention provides a method for cloud detection by using the difference in specific emissivity between clouds and underlying objects such as vegetation, bare soil, snow, sand and water in the long-wave radiation band of MODIS data.

[0029] 1. Theoretical Basis

[0030] According to the mutual effect of earth radiation and solar radiation, the earth radiation received by the sensor can be divided into three sections, namely short-wave radiation (0.3-2.5 μm), mid-infrared radiation (2.5-6 μm), and long-wave radiation (above 6 μm). The short-wave radiation is mainly reflected by the earth's surface to sunlight, and the heat radiation of the earth itself is ...