Heat source detection device

Patent metadata

Field	Value
Publication number	US-11933673-B2
Application number	US-201916970537-A
Country	US
Kind code	B2
Filing date	Feb 19, 2019
Priority date	Feb 19, 2018
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A heat source detection device is a heat source detection device that detects a heat source on the earth using observation data of a radiometer provided in a geostationary satellite and includes: a calculation unit that calculates a heat source proportion value indicating a proportion of a wavelength distribution due to the heat source included in the observation data to the observation data by curve fitting using Planck's law; and a determination unit that determines presence or absence of the heat source according to the heat source proportion value calculated by the calculation unit.

First claim

The invention claimed is:

1. A heat source detection device that detects a heat source on the earth using observation data of a radiometer provided in a geostationary satellite, the heat source detection device comprising:
a calculation unit that calculates a heat source proportion value indicating a proportion of a wavelength distribution due to the heat source included in the observation data to the observation data by curve fitting using Planck's law; and
a determination unit that determines presence or absence of the heat source according to the heat source proportion value calculated by the calculation unit,
wherein the calculation unit sets a first wavelength distribution D1, a second wavelength distribution D2 and a third wavelength distribution D3 based on predetermined temperatures determined according to a flaming state, a smoldering state and a background, respectively, calculates coefficients a, b and c satisfying a radiance G of the observation data=aD1+bD2+cD3 using a non-linear least squares method and sets the heat source proportion value to a/(a+b+c), b/(a+b+c) or c/(a+b+c).

2. The heat source detection device according to claim 1 , wherein the calculation unit calculates, as the heat source proportion value, a proportion of a wavelength distribution depending on a temperature of a heat source by a fire with flames to the observation data, and a proportion of a wavelength distribution depending on a temperature of a heat source by a fire only with smoke to the observation data.

3. The heat source detection device according to claim 1 , further comprising:
a storage unit that stores, in time series, heat source proportion values calculated by the calculation unit, wherein
the determination unit determines that the heat source is present when a change rate of the heat source proportion values in time series stored in the storage unit exceeds a threshold value.

4. The heat source detection device according to claim 1 , wherein the calculation unit calculates an esf by performing curve fitting using the non-linear least squares method, and until a difference between a radiance based on the calculated esf and the radiance G of the observation data converges on a fixed value or less, while adjusting the predetermined temperatures, the calculation unit repeats this procedure.

5. The heat source detection device according to claim 2 , further comprising:
a storage unit that stores, in time series, heat source proportion values calculated by the calculation unit, wherein
the determination unit determines that the heat source is present when a change rate of the heat source proportion values in time series stored in the storage unit exceeds a threshold value.

6. The heat source detection device according to claim 3 , wherein the determination unit calculates an average value in a fixed interval obtained by averaging, for each fixed interval, the heat source proportion values in time series stored in the storage unit and determines that the heat source is present when a change rate of the calculated average value exceeds a threshold value.

7. The heat source detection device according to claim 5 , wherein the determination unit calculates an average value in a fixed interval obtained by averaging, for each fixed interval, the heat source proportion values in time series stored in the storage unit and determines that the heat source is present when a change rate of the calculated average value exceeds a threshold value.

Assignees

• Ihi Corp

Inventors

• SASAGAWA Chiharu
• Ogai Takashi

Classifications

• G01J5/007 Primary

  for earth observation · CPC title

• G01J5/0066

  for hot spots detection · CPC title

• G01J2005/0077

  Imaging · CPC title

• G08B17/005 Primary

  for forest fires, e.g. detecting fires spread over a large or outdoors area (fire fighting forest fires A62C3/02) · CPC title

• G08B17/12

  Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions · CPC title