JPS62259073A - Sensing method for skein of birds - Google Patents

Abstract

PURPOSE:To sense a skein of birds irrelevantly to meteorological conditions and whether it is day or night by comparing a reflection image based upon detection pulses of an S band with a reflection image based upon detection pulses of an X band. CONSTITUTION:Reflected pulse signals of the X and S bands are both stored in a storage device temporarily and read out repeatedly at a period shorter than the storage period, and the read output is supplied to a cathode-ray tube display device to display its image. Then, the threshold level of the reception output of the S band is lowered almost to a noise level to increase the sensitivity more and STC is put in operation to suppress short-distance information. Consequently, a short-distance target including a ship an a skein of birds is confirmed through a binocular up to about 3 miles (about 6-7 miles under good conditions) and a skein of birds at longer distance appears in the reflection image of the S band, but does not appear in the reflection image of the X band. Consequently, it is identified from the ship, etc., appearing in both images.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a technique for searching for schools of surface-swimming fish such as bonito, yellowtail, hairtail, sardine, mackerel, tuna, and herring. This relates to a method for detecting flocks of seabirds such as black robins and black-bellied cuckoos.

(Prior Art and Problems) Binoculars have traditionally been used exclusively to detect flocks of birds of this type. However, 1. Even under the best weather conditions, the detection range with binoculars is 6.
Limited to ~7 miles.

2. Exploration is not possible in rainy, sunny or foggy weather.

3. After discovering a flock of crows, tracking them requires cooperation between the observer and the boat operator.

4,;,7. It is difficult to determine the distance to the group, making it difficult to determine the tracking order.

There were other problems.

(Means and effects for solving the problem) - The inventor discovered that while experimenting with a 10c-wavelength (S-band) pulse radar, commonly used on large commercial ships, for use in rough weather, the sensitivity was increased. In a certain type of image located far away, the team noticed a target that was not present in the 3cm wavelength (X-bud) pulse radar image and confirmed that it was a flock of birds.

Furthermore, since the antenna section of S-band radars is very large and heavy, they are rarely loaded onto fishing boats.

Normally, in order to detect small objects, the beam width is narrowed in a short wavelength band to increase the resolution of the detection beam. As mentioned above, it is currently not clear what is the basis for the phenomenon in which flocks of birds, which cannot be detected by X-band pulse waves despite their effective range, can be detected by pulse waves with longer wavelengths than X-band pulse waves. do not have.

The present invention combines a reflected image by a detection pulse in the S band and an X
By comparing the reflected images from the detection pulses in the band, bird flocks can be known regardless of weather conditions or day or night.

(Embodiment) Reflected pulse signals for both the X band and the S band are temporarily stored in a memory, the stored signals are read out repeatedly at a cycle shorter than the storage cycle, and the readout output is supplied to a cathode ray tube display for visualization. This configuration may be the same as that of a conventional so-called delay radar.

Note that the display may be provided separately for the X band and the S band, or the display may be divided into left and right sections. It is desirable that these displays be performed by XY scanning.

To implement the present invention with the above device, the threshold level of the S-band reception output is lowered to near the noise level. Furthermore, the sensitivity is increased and STC is activated to suppress short-range information.

In this way, short-range targets up to about 3 miles (6-7 miles under good conditions), including ships and flocks of birds, can be seen with binoculars, and flocks of birds over the above-mentioned distances can be seen using the S-band. Although it appears in the reflected image by X-band, it does not appear in the reflected image by X-band, so it can be distinguished from the ship etc. that appears in the single-car image.

(Effects of the Invention) According to the present invention, it is not only possible to detect long-distance flocks of birds, which were conventionally impossible to detect with binoculars, regardless of weather conditions, but also to detect the entire distance to the bird flocks. It has the advantage of being able to determine tracking priorities since it can be measured over the entire circumference.

Additionally, compared to relying on binoculars, one person can now detect and track flocks of birds, resulting in labor savings and operational efficiency.

Furthermore, it is possible to intuitively and visually grasp the relationship between other ships and their tracking bird flocks, as well as their relative positions with surrounding bird flocks.

In addition, since the detection field of view is much wider than that of binoculars, it is possible to eliminate detection errors.

Additionally, flocks of birds have been confirmed to exist in rainy areas and behind squalls, making it possible to greatly alleviate the conditions that limit detection (naked vision or binoculars).

Furthermore, it is possible to detect flocks of birds flying in clear skies in the early morning or at night, making it possible to detect schools of nocturnal fish by detecting flocks of birds.

Claims (1)

[Claims] 1) Compare the reflected signal from a predetermined airspace due to the S-band detection pulse wave with the reflected signal from the above airspace due to the X-band detection pulse wave on the cathode ray tube display, and A bird flock viewing method for detecting a bird flock based on the presence of the reflected wave image in the S band band and the absence of the reflected wave image in the X band band at a location.