DE2521296C3 - Navigation system with radar device and transponder for determining the angle of the radar and transponder - Google Patents

Description

The invention relates to a navigation system with a radar device as in the preamble of claim I. specified. Such a navigation system is known from US-PS 37 87 84I.

Knowing the angle of direction of a fixed station / 11 a mobile object. / .. B. one Ship, is often necessary to control the tax or the

To determine the orientation with respect to a reference axis.

Knowledge of the heading is particularly necessary to guide a mobile object when a heavy cargo ship, e.g. B. an oil tanker, supported by tugs, with which it is carried by ropes connected, maneuvered in a port. In foggy weather, the orientations of each For the tugs with regard to the tanker, the tugs' helmsmen only judge them badly Port surveillance station is useful if it knows the heading of the tanker and the tugs. she can then transmit commands relating to the maneuvers to be carried out to the helmsmen.

It is the object of the invention specified in claim 1 to provide a navigation system of the generic type to design that it is the angle required when used for traffic monitoring, regardless of the reception level provides.

When using the navigation system for traffic monitoring in a port, the Ships only necessary simple and cheap answering machines. All calculations are carried out at the location of the radar device.

The invention is explained in more detail with reference to the drawings, for example. It shows

F i g. I a diagram to explain the object of the invention,

2 shows the radiation diagram emitted by the transponder,

F i g. 3 the block diagram of the device according to the invention,

F i g. 4 a transponder with ρ antennas,

Fig.5 that of the transponder according to Fig.4 radiated radiation pattern,

6 shows the block diagram of a radar device provided for the fixed station.

The determination of the heading of a ship M to a stationary station P is first explained with reference to FIG. 1. The heading is determined by the angle γ, which is given by the direction MU of the longitudinal axis of the ship and the north direction MN . The heading angle γ can be determined from the direction angle ß, which is determined by the connection of the fixed station P to the ship M and the longitudinal axis of the ship M , and from the direction angle Θ, which is a reference axis PZ determined by the connection of the fixed station P to the ship Mouth , be calculated.

Has the angle θ been determined in a known manner, e.g. B. by a radar device, then the task of determining the direction angle γ is reduced to the measurement of the angle ß.

From Fig. 2 it can be seen how the angle β is measured in the new navigation system. The stationary station contains a Doppler radar device 1 with a swiveling directional antenna. The ship Mist equipped with a transponder 2. The transponder 2 contains two fixed directional antennas. The radiation characteristics of the two antennas are the same. Thus, their ancestral gains also match. The electrical axes of the two radiation diagrams form an angle 2a. The direction of the bisector of this angle 2.7 agrees with the direction MU of the ship's longitudinal axis. The radiation di.ignimme el \ and c / 2 of the two directional antennas, of which only the main areas are shown in the drawing, intersect on the bisector M / /. H. at the J dliPunkt.

The incoming signal from the Doppler radar

device 1 comes and that is received by the two directional antennas of the transponder 2, is phase modulated with a periodic signal before the return radiation. A sinusoidal wave, for example, can be used as the periodic signal. The ^r , amplitude of this wave is the same for both directional antennas; the frequency is different for the two directional antennas.

The following terms are used in the description: in

/ fr »= A cos Ω f

the incoming signal received by the transponder; it has an amplitude A and an angular velocity β corresponding to a frequency F;

Φ \ (ή = Φ% \ ηω If

the sinusoidal wave with which the signal l (t) is phase modulated; the amplitude is Φ and the • angular velocity corresponding to the frequency f \ is ω 1;

G (Kf β) is the gain of the directional antenna with the radiation diagram d \ in the direction of the Doppler radar device I;

G (k-ß) is the gain of the directional antenna with the radiation pattern d2 in the direction of the Doppler radar device I;

R \ (t) andR2 (t)

are the signals transmitted back by the two directional antennas in the direction of the Doppler radar device.

The signals R \ (t) and R 2 (t) are determined by the phase shifts' JMfrlund Φ2 (0 ) caused by the transponder and by the antenna gains G (n. + Ss) and G (tx-ß) determined by the directional antennas.

Thus:

R \ (t) -
R 2 (0 =

the other sinusoidal wave with which the signal The following calculations are made for the signal

I (t) is phase modulated; the amplitude is Φ and RUO is carried out. You are for the signal R2 (t)

the angular 25 corresponding to the frequency f2 is identical,

speed is ω 2. One can write:

RI (t) = AG (. * + T <) cos (Ut + Φ sin ,., I f),

RI (t) = AG (λ + / ί) [cos U · r · cos (Φ sin , · < 11) - sin üt ■ sin (Φ sin «> 1r)], (1)

The expressions cos (0sin »>» 1 t) and sin (</> sin «, I /) can be transformed by introducing bucket functions:

cos (0 sin o, 11) = J ₀ (0) + 22 Ji _n ( ¹ V) cos 2 now

m = I

sin (0 sin f »I i) = 2] £ J _2m _, (0) sin (2 ^m - I) -Ii,

Dl = 1

where J ₂ mW and J _2m -i (0) represent the Bessel functions of the orders 2m and 2m - 1 with the argument Φ .

Accordingly, equation (I) can be written in the following form:

RI (t) = AG (λ + ti)

cos Ut + cos Ut ■ cos 2m (-. U

Bl = I

Bt = I <iin (2m-I) m Ii

By converting the cos and sin products into cos-S'imneii and differences, one obtains:

Rl (i) = AG (* +

J _o (</>) · cos </> f + Υ. J _{2 m} ('/') cos (U + 2 m «, \) t

W - 2m-

Bl = I + ■ '

Bl = I - I) -I] r

^C0S I ⁷ "+ < ² '» -

It is known that

J ₂ "(Φ) = (- I) ² '" J ₂ J <I>) = J., "('/>)
Λ », il '/' l = (- D ^2m ' J, i " ,, ('"I = -J _(2m ,, ('/').
Equation (2) can be written as:

RI (O = / 1 OM> + / ')

J "('/') cos IJi + 2 -Z ₂ J '") tos (! _> + 2 m. ·. I) I

f ^ J, J '/') COS (. '.' 2 ffl ei I) f

m = I

t /

+ Σ · ⁷ «J-!, C'K-osl !. ' (2m - I) d] ι

IR = I

t Σ ^ 3 «, ('" »cos [WI (2m - l) cl | ι

m = II

Hence:

f T

KI (O = AC, [\ f / (»J) J _n ('") cos [U + Ii ei I) f.

The calculations carried out for the signal R I (O also apply to the signal R 2 (/). Therefore:

R 2 (0 = .Ί C; (χ - / () £ J _n C ") cos (!. '+ / Ι .., 2) ί.

η = - f

The total signal R (t). that are reflected back from the transponder in by the two directional antennas, the direction of the Doppler radar device is reflected back together,
is made up of the signals R \ (l) and R 2 (l). the s> is thus:

R (I) = AG (\ + / ι) 2j- / _n ('") cos (/.' + / Ιei I) ί + .4 GM * - t <) ZjJ

η = - τ π = - χ

One can derive from this conclusion. that the amplitude 52 of the lateral line increases by uci ricqucn /.

Middle of the frequency spectrum of the signal R (t) at the F '+ (2 is equal to:

Frequency F. that of the frequency of the incident signal O - A'Ci Ά \\\ ΙΦ \

corresponds, and that at the frequencies F + nf \ 45 ~~

and f + nf2 side lines are present. If one forms the ratio Q of the difference 51 -S2

If the Doppler effect are disregarded and the sum S1 + S2 of the amplitude, then we get

can which is the case. when the ship is not moving, you:

is the ^ j _ gj G (\ + ti) - G {\ - ti) received by the Doppler radar device

Frequency spectrum equal to the frequency spectrum of the> o Q = - == = - - ψ- . .

signal R (i) emitted by the transponder. ^S ' ^{+ S2} G (% + / f) + O (· »- ,, _t

However, if one considers the Doppler effect on the frequency the angle λ is known and depends on the

F considered, then the center of the orientation of the two directional antennas of the response

Frequency spectrum of the advises against the Doppler radar device. It follows that as long as the angle β

received signal at a compared to the frequency 55 is equal to or less than <x , the ratio Q only of that

F shifted frequency F '. It is assumed that angle β depends.

the effect of the Doppler effect on the frequencies With the in F i g. This is the angle β shown in 2

f \ and (2 is negligible. Ratio Q is negative. If the angle β is the

For the evaluation one is only at the first opposite sign, i.e. H. if that

Lateral lines with the frequencies F '+ f \ and F' + / "2 bo Doppler radar device would be located above the direction MU ,

Interested. the sign of the ratio Q would be positive.

The amplitude SI of the sideline with the frequency Fig. 3 shows a block diagram of the navigation system

F '+ f \ equals: equipment necessary for the system. The responder

has two identical, fixed directional antennas

Si = A 'G («-r ß) J 1 (Φ). 65 Ai and A 2, e.g. B. Mikroweüenhömer, their electrical

Axes form an angle 2tx . Each antenna are one

where A '< Λ, due to the damping during controllable phase shifters Di or D 2 (the electrical

the signal propagation. see properties of these phase shifters are identical

lisch) and a short circuit ( ¹ I or ('2. which reflects the incident wave, connected downstream. The phase shifter D I is controlled by a sine wave generator Cl I with the frequency A1 so that the phase shift between the incident and the from the antenna 4 I reflected signal are equal to Φ (i »W is. while the phase shifter D 2 is controlled by Jem sine wave general Cl 2 with the frequency. A2 so that the generated phase shift is equal to Φ sin (f) l /. in

The fixed station is us tlciri Oopplcrradar gets mil a transmitter 5 and a Fmpfänger 4. mil a swiveling directional antenna 5 are connected that the direction angle which the responder is in a known manner H. the Fnlferming and the speed of the vessel, \ < , determined. When the pivotable antenna 5 is directed in the direction of the ship, thin lines in the frequency range "vtir'r tier Λι'ΗΟμπγ L'm | jt, irrgcriiMi signals, itinci tier center line with the frequency P. anstieren compared with" tier The radiated frequency contains the speed of the ship, the ropes with frequencies PfAI and Pt A2, which belong to the signals radiated back by the antennas 41 and 42. Your receiver 4 is a circuit for frequency selection and amplitude Tuning that supplies the amplitude and the frequencies / ■ "f A 1 and / ■"'+ / 2 and a computer 7. tier for determining the direction angle // the arithmetic opera

tion _ '.- carried out. refilled. "

j I ~ t ~ Λ 2.

In Fig. 4 a response device with /> antennas (/> -H) is shown: This enables an angle determination over a range of JhO. Ils are eight fixed directional antennas 4 I to 4 8. ζ. Β. Microwave horns. intended. In these directional antennas wirtl the phase of the filling signal with periodic signals, z. H. sinusoidal waves, each modulated with one of the I frequencies A1 to A8. The electrical axes of two adjacent antennas. / .. B. 4 I and w

4 8. form an angle 2λ. where 2, \ - ³ ^. the

The longitudinal axis MU of the ship coincides with the bisector of the angle 2, \. by the electrical axes of two adjacent antennas, e.g. B. Λ I and r. 4 8. is formed, match.

The main lobes of the radiation pattern * emitted by such an arrangement are shown in FIG. 5 shown. The eight radiation circles d \ to c / 8. which are assigned to the eight antennas are identical and "><i evenly distributed over 360". The axes of the intersection of two consecutive lobes

generate the angle:.. in the case shown in Fig 5, this angle is 45 "thus form the r axis X'X of the intersection points of the lobes d \ and d2 and the lobes of the d \ and c / 8 // Wi7eincn angle. of 45 ". The axis of the intersection points VV of the lobes t / 2 and i / 3 forms an angle of 90 " with the axis MU

USW M)

The Doppler radar set in the stationary station receives a combination of several

rer of the signals with tle'i frequencies / ■ "t Al. / ·"'+ 12

/ ■ "'+ A8. Which are emitted by the transponder. The direction is determined from the two frequencies of the eight frequencies, the signals of which have the greatest amplitude at the stationary station. For this, the ratio Q is formed, as already described. Here, however, the angle is determined which is determined by the axis through the intersection points of the two lobes with the greatest intensity, which correspond to the two selected frequencies, and the axis MU i / 2 correspond to the value added by 45 to the particular one of (^ angular In FIG b is a Doppler radar device is shown, which cooperates with a response device with /> directional antennas Vs includes a transmitter 1 and a l.ntpfänger 4:... the are connected to a swiveling directional antenna 5. Direction, distance and Gcschwin urpr ^ eii ticS .WimmS wOi'uCTi »iüi uuKiinfiiC ttCiSC Ci'imiiC'ri.

The F.mpfängLT is a circuit 8 for frequency selection tion and amplitude determination downstream. the the

Amplitudes of the frequency lines / "+ Al. L" + l'2

/ · "T /" returns 8. This circuit 8, in turn, is followed by an aniplitude discriminator 9. who selects the two great amplitudes and animal frequencies from the at hl amplitudes that are assigned to the eight frequencies. These two frequencies are fed to a decoding circuit 10. This decoding circuit 10 supplies a computer II with a value which is determined by the angle formed by the longitudinal axis of the ship and the straight line connecting the intersection points of the two lobes associated with the two selected frequencies. The computer II determines the value for Q and, taking into account the values supplied by the Dckodicrschallung 10, the angular direction.

The above navigation system was described in the context of a Doppler radar device; however, a normal radar device can also be used instead of the Doppler radar device. Also> n this case, the response device over an angle of IHO "tHeii'hiiiäUit * spread and fixed directional antennas, however, the incident signal is amplitude-modulated by these antennas. The Modulationssignalc are, as before, periodically and have different frequencies. From the radar device the various modulation frequencies are then determined, and the calculations are carried out, as before, with the amplitudes corresponding to these frequencies.

With this navigation system it is possible that from of the stationary station from the direction of a stationary station with respect to a mobile object on which just a transponder of the type described, which takes up little space and does not require a computer, can be determined.

This navigation system also allows the direction of a mobile object to be determined in relation to one another to a stationary station on board the mobile object. The transponder is then located the on-board device of the mobile object is used for the stationary station and as a radar device.

For this purpose 3 sheets of Zcichnuimeii 030 215/207

Claims (2)

Patent claims: 1. Navigation system with a radar device and a response device with at least two antennas, ^r > each of which is assigned a modulation device, one of the two stations being mobile, in which a first electromagnetic wave is emitted by the radar device in the direction of the response device Responder in one m plane two further electromagnetic waves, each with a club-shaped radiation diagram, which are the first electromagnetic wave modulated with different modulation frequencies, are emitted, and in which, with the help of the two electromagnetic waves, the angle between the connection radar device - responder and one through the The preferred direction determined by the axis of symmetry of the two radiation beams is determined by a subjective comparison of the amplitudes of the two Emufangssignale and with the radar device by pivoting a radar beam the angle between a reference axis and the connection between the radar device and the transponder is determined, d acharacterized by the fact that with additional derivation of the sum (S \ +52) of the amplitudes of the received signals from the two radiation lobes (d) the angle (ß) between the connection radar device fT ^ response device fM ^ and the preferred direction (MU) in a manner known per se m formation of the quotient (Q) from the difference (S \ - 52) and the sum (51 + 52) is determined. 2. Navigstionssystevn according to claim 1, characterized in that mohr as two antennas (A) are arranged evenly on a circle L! That the radiation patterns (d) of two of these antennas (A) as well as the radiation patterns (d \, di), which determine the preferred direction (MU) , overlap so that the electromagnetic waves emitted by the other antennas are also modulated with different low frequencies, whereby the positions of the antennas (A) on the circle and thus the axis of symmetry are modulated by these low frequencies (e.g. XX) of two adjacent radiation diagrams are coded. 4-, and with the symmetry axes of the other radiation diagrams determined weathering directions. That in the radar device (1; 3 to II) from the two radiation diagrams with the greatest intensity as in the case of only two radiation diagrams (Fig. 2 , d \, t / 2) an angle is calculated, this angle, corrected by the angle between the axis of symmetry (e.g. XX ') of these two radiation lobes and the preferred direction (MU), the angle (β) between the connection r, radar device (P) -AiMwortstation (M) and the preferred direction is.