JPH03295487A - Detecting method for space floating body - Google Patents

Abstract

PURPOSE:To improve the detection accuracy while realizing a device whose transmitter and antenna are balanced in size without increasing its size by providing a primary radar which uses CW, separating transmission and reception, and installing the both at different places. CONSTITUTION:A transmission device 1 and a reception device 5 are connected mutually through a broken piece 3 and a transmission line 6. When a pseudo random code (PN code) is modulated in a sent wave 2, the reception device can receive this code as long as the broken piece 3 is irradiated. There are many obstacles between two points P1 and P2, so a signal sent from the point P1 is reflected at the point P2 and received at the point P1 previously and the time of its transmission between them is measured to know the distance of the electric path. Knowing that the difference between the direct distance and this distance is an extra distance as a bias component, the direct distance between the points P1 and P2 through the transmission line 6 can be found substantially.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the treatment of space debris (debris) floating in outer space.
e).

[Conventional technology]

Various space developments have been carried out so far, and as a result, there are currently many pieces of debris floating in space.

Space floating objects (Debrie) floating in this outer space (
Hereinafter referred to as fragments. ] 1/-da was used to detect all of the debris because the C debris does not carry a transponder like those found in artificial satellites.

Next you have to use radar. - The entire configuration of the next radar is shown in FIG.

■ is radar, 31) is transmitted wave, C32 is reflected wave, (
) is a fragment. Does the radar (to) beam a beam to the target debris using a high-gain antenna? This radio wave, which radiates all the focused radio waves, is the effective cross-sectional area of the debris (Cross E!ee
A reflected wave proportional to tYon) is generated, and this scattered wave is received by the complete radar.

[Problem to be solved by the invention]

Radar characteristics are expressed by the radar equation.

Here, Pr is scattered and returned to the radar antenna power density Pt: Transmission power Gt: Transmission antenna gain Ar: Receiving antenna effective area R: Radar target distance σ: Effective cross-sectional area of target For the primary radar, formula (1) is used. applies.

If you want to get as much power as possible from small pieces, you can either reduce all the molecules on the right side of equation 11 or 9
There are only two ways to increase the denominator. Since the altitude of the debris is constant, it is not possible to improve R, so the only option is to increase the transmit power or increase the total transmitting and receiving antenna gain, but in order to achieve this, the hardware must be completely large. It is necessary to

This invention was made to solve all of these problems, and is based on continuous wave technology.

The purpose is to increase received power over a long period of time without increasing the size of the hardware.

[Means to solve all problems]

The space floating object detection device according to the present invention has a primary radar using CW, and since it is difficult to separate the transmission and reception of the primary radar when CW waves 2 are used, the transmission and reception are completely separated and both are placed in separate locations. The configuration is such that it can be installed.

[Effect]

This invention avoids increasing the scale of the device by making full use of CW waves due to the single high-pointed shell required for pulse radar, and achieves a balance between the size of the transmitter and antenna.
can be realized.

〔Example〕

FIG. 1 shows a block diagram of the present invention. +11 is a transmitting device equipped with an antenna and a transmitter that has high directivity and can direct its beam over a wide range in elevation and azimuth directions;
(2) is the transmitted wave, (3) is the debris, (4) is the reflected wave, (5
) is a receiving device equipped with the same antenna and receiver as the transmitting device (1), (6) is the transmission line, (7) is the transmission angle, (
8) is the reception angle.

The transmitting device +11 transmits a transmission wave (2) toward the fragment (3). Scattered waves are generated from the fragments (3) irradiated with radio waves. The antenna of the receiving device (5), a part of which is received by the receiving device (5), is oriented towards the fragment (31), and the received wave (4) is directed from the direction of the main lobe of the antenna.
Receive all.

While the transmitting device f(1) and the receiving device (5) are transmitting and receiving the debris (3) via the transmitting wave (2) and the receiving wave (4), the transmitting device (1) has a transmitting angle of +71'i, Receiving device (5
) maintains the reception angle (8).

1. A method for detecting the height of the fragment (3) using angle information will be described.

The transmitting device (1) and receiving device 15) are installed on the triangular side lid based on the reference triangular point or on the GPS (Global Pa
locationing system) can be used to calculate the geographical position. The transmitting angle (7) and the receiving angle (8), where these points are P1 and Pl, are the angles at which the debris (3) is viewed from the points P1 and Pl, respectively, and are the bottom of the elevation angle and azimuth angle, respectively. Ru. Therefore, the position of the fragment (3) can be calculated at the intersection of the line segments drawn from the points P1 and Pl toward the fragment (3) at the transmitting angle (7) and the receiving angle (8).

Next, we will describe a method of detecting one position using the contents of transmitted and received waves in order to improve observation accuracy.

The transmitting device +11 and the receiving device (5) are connected through the fragment (3) and the transmission line (6). The transmitted waves are periodic.

Moreover, it is possible to modulate with information that allows specifying an arbitrary point in two periods with high precision. For example, a pseudorandom code (PsuθdORancLom
C! od, e (hereinafter referred to as PN code) can be applied.

Superstition wave (if this attachment is changed to 'L' on 21, fragments (3)
The receiving device (5) can receive all the codes in one line that is irradiated. All receivers of the same code can be transmitted through the transmission line (6) to the receiving device 15). It is desirable to connect the transmission line (6) with a straight line between points P1 and P2, but since there are usually many obstacles between the two points, there are many obstacles when connecting the transmission line with a micro line or optical cable. Take the detour. Therefore, the distance of the electrical path and the direct distance connecting the two points P1 and P2 do not match. Therefore, by reflecting the signal transmitted from two points P1 in advance at all points P2, receiving it again at point P1, and measuring the entire time during this time,
You can know the distance of an electrical path. The difference between the direct distance and this distance can essentially be determined as the entire direct distance between points P1 and P2 through the transmission line (6), knowing that there is an extra distance as a bias component.

If the receiving device (5) compares these two signals, point P
It is possible to detect the difference between the direct distance between 1 and 22 and the distance covered by the fragment (3).

The second item 1 shows the geometrical positional relationship. α
[Pl at the position of the transmitting device, αB is P2 at the position of the receiving device, (1') i4f one side position 1ft, T P3
, (+31!,'i5('i-axis x, (141 is the coordinate axis y, d51 is an ellipse.
A curve in which the difference between the 1F4 distance between 11 and the distance via point P3α3 is constant is on an ellipse whose focal points are points P1αG and P2dll. It becomes an ellipse on a plane parallel to xmαJ and y-axis α↓, but the actual geometric relationship is that it is arranged in three dimensions,
Therefore, the surface that satisfies the flexibility with a constant distance difference is the X-axis α
It can be seen that it is the surface of a spheroid with axis j as the center.

When detecting a position by angle measurement, the absolute position error increases as the distance increases (although it is possible to measure time with high precision at measurement points with distance differences).

The error of the ellipse α can be completely improved in accuracy compared to angle measurement.

That is, by combining angle measurement and distance difference measurement, it becomes possible to detect a position with higher accuracy.

The Densaka used for the search uses code-modulated CW gold.

A pseudorandom noise code is used as the code.

The PN code transmitted by the transmitting device (1) and the receiving device (5)
The relationship between the two PN codes received by 6.'' is shown in FIG.

In the figure, ■ is a code from the transmitting device, ``■'' is a direct signal via one transmission line (6), ``■'' is a received signal, and ``■'' is one block of a PN code. C is the propagation delay or delay time from the sending device (1) that the direct signal 2d has, and +271 is the propagation delay time between the direct signal 121) and the received signal cab. is 1. It becomes a pseudo-random code such as j, , but in reality, the series of combinations of 0 and 1 shown in the figure υ holds true. The lengths of 0 and 1 are iui determined by selecting the type of PN code, i,
The code lengths of all the characters in jt k...a are the same, and one block is made up of consecutive characters.

Is the receiving device (5) a correlator for this PN code? We are equipped with
After receiving the direct signal at+ and the received signal, its phase tone can be read. By completely comparing these two phase differences, the time delay of these two waves can be detected.

Effects of reduction] In this paper, does the size of the transmitting section of the radar become larger compared to a pulse radar due to the ink used in this publication? By actively doing this, it is possible to take advantage of the features of the old geometric configuration and improve the total detection area of space floating objects.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, and FIG. 2 is a transmitting device. A diagram showing the geometrical positional relationship between the receiving device and the fragments,
FIG. 3 is a diagram showing the entire structure of a PN code, and FIG. 4 is a diagram showing the entire structure of a conventional primary code. In the figure, (1) is the transmitter, (2) is the superstition wave, and (3)
is a fragment, (4) is a reflected wave, (5) is a receiving device, te+
is the transmission line. (7) is the transmitting angle, (8) is the receiving angle, QO is the transmitting device position Pi, (1B is the receiving device position P2. (l)
is the position of the fragment P3. (1: i is the coordinate axis
and 5 are one block of the PN code, @ is the delay time between the transmitted signal and the direct signal, and @ is the delay time between the direct signal and the received signal. Ca1l is a transmitted wave, ■ is a reflected wave, and □□□ is a fragment. 4 Figure 3

Claims (2)

[Claims] (1) A transmitter equipped with an antenna and a transmitter that has high directivity and can direct its beam over a wide range of elevation and azimuth directions toward space floating objects floating in space, with periodicity. The system transmits continuous radio waves modulated with a pseudo-random code in which the occurrence of 0s and 1s is extremely arbitrary, and is equipped with an antenna and receiver similar to the transmitter to collect the radio waves scattered from the above-mentioned space floating object. Detecting the position of the space floating object by receiving it with a receiving device and based on the angle at which the transmitting device and the receiving device are facing the space floating object and the geographical position of the transmitting device and the receiving device. A space floating object detection method characterized by: (2) A transmission line capable of transmitting the pseudo-random code is provided between the transmitting device and the receiving device, and the receiving device has two pseudo-random codes, one via the floating object in outer space and the other via the transmission line. A three-dimensional ellipse in which a space floating object exists can be obtained by using the distance difference information obtained by comparing the phases of random codes and focusing on the positions of the transmitting device and the receiving device on the earth. A space floating object detection method according to claim (1).