System and method for measuring water depth using radar image processing
AssigneeKorea Institute of Ocean Science & Technology
InventorsMoonjin Lee, Tae Sung Kim, Yong Myung Kim
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Abstract
Provided are an apparatus and a method for measuring water depth. In order to solve a problem of water depth measurement apparatuses and methods in the related art, provided are a system and a method for measuring water depth using radar image processing, wherein an underwater environment, such as the shape of a seafloor surface, is more accurately recognized through analysis of a SAR image using synthetic-aperture radar (SAR), and thus, more efficient and accurate water depth measurement is achieved for a wide region with a relatively simple configuration and low cost.
Claims12
A system for measuring water depth using radar image processing, the system comprising:
- a data collector configured to receive predetermined various types of data for water depth measurement, the predetermined various types of data including a SAR image received through a synthetic-aperture radar (SAR) device;
- a data analyzer configured to measure water depth at a predetermined particular point or region in the SAR image through image analysis of the SAR image received through the data collector;
- and
- an output part configured to output various types of information according to predetermined settings, the various types of information including the various types of data collected through the data collector and processing processes and processing results processed through the data analyzer,
- wherein the data analyzer is configured to calculate, on the basis of information on a period (T) and a wavelength (L) of a wave in a measurement region received through the data collector and a dispersion relation equation of surface gravity waves, the water depth (h) using Equation below
- h
- =
- 1
- k
-
- tanh
- -
- 1
- (
- ω
- 2
- gk
- )
- (herein, h denotes the water depth, k denotes a wavenumber (k=2π/L), ω denotes an angular frequency (ω=2π/T), and g denotes gravitational acceleration),
- wherein the data analyzer is configured to apply 2D fast Fourier transform (FFT) to the SAR image received through the data collector, and calculate the wavenumber from wavenumber vector components (kx, ky) in x and y directions in a 2D spectrum and determine a wavelength of a swell using Equation below
- k
- =
- k
- x
- 2
- +
- k
- y
- 2
- ω
- =
- 2
-
- π
- k
- x
- 2
- +
- k
- y
- 2
- θ
- =
- tan
- -
- 1
- (
- k
- y
- k
- x
- )
- sin
-
- θ
- =
- λ
- 2
-
- L
-
- or
-
- L
- =
- λ
- 2
-
- sin
-
- θ
- (herein, L denotes a wavelength of a sea level wave, and λ denotes a wavelength of a radar wave).
Dependencies are inferred from the claim text.