JPS6355417A - Predicting method for waves - Google Patents

Abstract

PURPOSE:To exactly predict waves data in an expected course of a marine vessel, by utilizing waves data which have been informed, and deriving mathematically two equal wave height lines for placing an expected position of the own vessel between them. CONSTITUTION:An interpolating calculation by a spline method is executed from an observation data of each lattice point 3 in the periphery of the own vessel expected position, which has been received, two equal wave height curves 7, 8 for placing the own vessel expected position 2 between them are derived, and in proportion to distances 9, 10 between the equal wave height curves 7, 8 and the own vessel expected position 2, a wave height in the own vessel expected position 2 is derived. In this regard, as for a point 6 on the seal surface, a longitude line 4 and a latitude line 5 between each adjacent lattice 3 is are subdivided (for instance, divided into ten equal parts), and from among them, the point 6 having the same data is selected. Also, the selection of the point 6, the calculation of the equal wave height curves 7, 8, and the interpolating calculation are all performed automatically by using an electronic computer, and the equal wave height curves 7, 8 and the own vessel expected position of a result of arithmetic operation are displayed on an electronic drawing. In this way, waves data can be predicted scientifically and exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wave prediction method capable of accurately predicting wave data on the expected course of a ship navigating on the sea or the like.

[Conventional technology] The conventional method for predicting wave data on a ship's expected course, which plays an important role in ensuring safe and economical navigation of ships, is to use pressure distribution, wave data, etc. reported by public organizations. Ship crews have relied on their experience and intuition to make predictions based on regular forecasts and current situation information.

[Problems to be solved by the invention] However, the above-mentioned prediction method requires many years of experience and relies on personal judgment, so it lacks accuracy and sometimes fails to produce accurate predictions. .

[Means for Solving the Problems] In view of the above-mentioned problems, the present invention was made in order to provide a method for predicting wave data scientifically and accurately.
The gist is to use wave data, including wave heights separately observed and reported at each grid point set in the water area surrounding the ship's expected position, to mathematically calculate two iso-wave height lines that sandwich the ship's expected position. and interpolate the distance from the own ship's position to each equal wave height line to predict the wave height at the expected own ship's position,
In addition, similar techniques are used to predict wave direction, etc.

[Operation] Since the wave data observed at each grid point is mathematically processed and predicted, predictions can be made scientifically and accurately.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. The figure shows an example of this method. In the figure, 1 is the current position of the own ship, 2 is the expected position of the own ship after the elapse of the specified time,
This method uses wave data observed at each grid point 3 (indicated by a black circle), which will be described later, to mathematically predict the waves at the predicted own ship position 2, which is outside the grid point 3.

Grid points 3 are given as the intersections of lines of longitude 4 and lines of latitude 5, which are divided into basic patterns at intervals of 380 km, and among these grid points 3, each grid point in the sea area that is recognized as particularly necessary for ship navigation Regarding 3, each country's meteorological observation organization and ships navigating in the area will report to each country's central government office (
Meteorological and oceanographic data (wind speed,
Wind direction, wave height, wave direction, etc.) are reported by wireless telegraph.

In the present invention, upon receiving the notification, interpolation calculations are performed using the spline method based on observation data (wave height, wave direction, etc.) at each grid point 3 around the predicted own ship position, thereby making a prediction at the expected own ship position. The spline method is a method of mathematically finding a curve called a contour line by connecting a required number of points 6 (indicated by white circles) on the sea surface that exhibit the same wave height with an n-dimensional curve (contour lines indicating the altitude on a map are connected by an n-dimensional curve). Using this method, two equal wave height curves 7.8 sandwiching own ship's expected position 2 are found, and the distance between equal wave height curve 7.8 and own ship's expected position 2 is 9.10. Find the wave height at own ship's predicted position 2 in proportion to . Note that for the points 6 on the sea surface described above, the longitude lines 4 and latitude lines 5 between adjacent grid points 3 are divided finely (for example, into 10 equal parts), and points 6 having the same data are selected from among these.

The selection of point 6, the indexing of equal wave height curves 7 and 8, and the interpolation calculations are all performed automatically using an electronic computer, and the calculated equal wave height curve 7.8 and own ship's estimated position 2 are displayed on an electronic screen (not shown). displayed above.

Note that if a cubic curve is used as the n-dimensional curve, calculation is easy and sufficient accuracy can be obtained, which is convenient in practice.

Furthermore, the wave direction can be similarly calculated by interpolation using the spline method, and all necessary data can be predicted.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various changes may be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, the present invention exhibits the following excellent effects.

(1) Points on the sea showing the same data are found based on observation data at grid points, and interpolation calculations are performed using the spline method, so wave data can be predicted scientifically and accurately.

Oi) As a result of item 0, it is possible to select the optimal route necessary for economical operation of the ship and perform avoidance maneuvers for safe navigation.

[Brief explanation of the drawing]

The figure is an explanatory diagram for implementing the method of the present invention. In the figure, 2 indicates the predicted own ship position, 3 indicates the grid point, and 7.8 indicates the equal wave height curve.

Claims (1)

[Claims] 1) Using wave data including wave heights separately observed and reported for each grid point set in the water area surrounding the ship's expected position, mathematically find two equal wave height lines that sandwich the ship's expected position. , a wave prediction characterized by interpolating the distance from the own ship's expected position to each equal wave height line to predict the wave height at the own ship's expected position, and also predicting wave direction etc. using a similar method. Method.