DE1766645C3 - Method for determining the bearing side and polarization of a sky wave field and arrangement for carrying out the method - Google Patents

Description

The invention relates to a method for determining the bearing side and polarization of a space wave field and an arrangement for carrying out the method using a dual-channel visual radio direction finder E ₁ - £ "cos (w /) sin 2ε

E ₁ - r "£" cos (w / + V) sin 2e

H ₁ = // "cos (fof + qi) sin 2ε

H _x - γΉ " cos (w / j ψ + λ ¹ ) sin le.

One sign "refers to a vibration In the plane of incidence, the sign 1 indicates an oscillation perpendicular to it, in which proportions one can decompose an elliptically polarized wave.

r / is the phase difference between the electrical and the associated magnetic oscillation.

The first two relationships can be rewritten

E j, - H ¹ Z ₀ cos (η / sin Ir

E _x = r "H ¹ Z ₀ cos (w / 4- λ") sin 2f.

The two quotients are now obtained by dividing

7 =

H ₁ _ / - ¹ COs (W / 4-

^H "

4- V)

r " cos (ω / + x")

H ¹

If one understands the stresses //, · Z ₀ , £ ₂ or H _x - Z ₀ , £ ", as two ellipses standing at right angles to each other, then the equations (a), (b) allow the following interpretation:

Equation (a) represents the polarization ellipse of the space wave. Equation (b) represents the polarization ellipse the reflected sky wave.

The two equations further show that the Ellipse (b) is smaller than ellipse (a), since it holds in any case

r " <1

With this the bearing side of the incident field can be determined: One compares the two ellipses, crmit ilt the smaller of the two and assigns the Direction in which the associated antennas (1Ϊ yen to the true bearing side of the incoming skywave.

F i g. 2 shows the block diagram of an arrangement with which the polarization and bearing side of the field can be determined in principle using these relationships. The dipole antenna D \ and loop antenna R \ calibrated to the same voltage consumption by means of the amplitude control element I and phase control element 2 are rotated one after the other in the directions of the space wave (1) and the reflected space wilt: (2). The antenna voltages are fed to the amplifiers 3, 3 'of the visual radio direction finder. On the

ίο ßraunschen indicator tubes4 then arise one after the other two ellipses, which are equal to the two polarization ellipses. The waiire bearing side of the Raumellenfeldes is equal to the adjustment direction of the antennas, which corresponds to the smaller of the two ellipses.

F i g. 3 shows the block diagram of an arrangement according to FIG. 2 for the practical determination of polarization and bearing side of the sky wave field. The two antennas are replaced by an equivalent one,

ao known combination.> n three loop antennas each and three dipole antennas pointing perpendicular to each other in the three directions of the room, four goniometers 5, 5 'and 6, 6', their search coils in the azimuth /; and by means of two coupled

The switch 7, T point to the elevation -f ε of the space wave and -ε of the reflected space wave. Depending on the position of the switches 7, T , one of the two ellipses appears on the indicator tube 4, from which the polarization and bearing side of the space wave field can then be taken.

F i g. 4 finally shows the circuit diagram of an arrangement according to FIG. 3, with which you can see the target side of the field can be determined particularly easily. It differs from the arrangement according to FIG. 2 in that the two voltages fed to the radio direction finder are connected by means of two Switch 8,8 'in quick time keying one after the other the amplifiers 3, 3 'are fed. Depending on the position, then arise on the Braunschein pipe the switch 7,7 'has two different axboxes, of which the one with the shorter line lengths is assigned to the bearing side of the sky wave.

1 sheet of drawings

Claims (5)

Patent claims: 1. Procedure for determining DF ropes and Polarization of a space wave field, characterized in that a combination an electric and a magnetic dipole in the same axial direction and the same sensitivity and phase position one after the other with the axis in the direction of the incident and the reflected Field is rotated and the antenna voltages via a double channel amplifier in the two cases placed on the crossed pairs of baffles of a Braun tube so that the resulting display ellipses give an image of the polarization of the incident or reflected wave field result and due to their different sizes, the distinction between the two fields and thus one enable clear determination of the direction of incidence of the primary field (bearing side). 2. Arrangement for performing the method according to claim 1, characterized in that In the derivation of one or both antennas, amplitude and phase control elements are switched on which make it possible to have the same amount and phase as the receptivity of the two antennas make fcu. 3. Arrangements for performing the method according to claim 1 or 2, characterized in that to avoid rotation of the antennas themselves for each direction (.v, y, z) of the room a separate combination of electrical and magnetic dipole is provided and that in each case two horizontal dipoles or two vertical frames are combined into a single output by synchronously operated goniometers and that the two outputs mentioned are also combined with the outputs of the vertical dipole or the horizontal frame via two further synchronously operated goniometers, so that any Can simulate rotation of the simple arrangement according to claims 1 and 2 in any direction of space. 4. Arrangement according to claim 3, characterized in that for determining the direction of incidence of the primary field one of the field windings of the one used for height adjustment coupled goniometer can be reversed. 5. Arrangement for carrying out the method according to claim 1, 2, 3 or 4, characterized thereby, that using two coupled changeover switches the antenna voltages one after the other • To the amplifier inputs of the visual direction finder be introduced, whereby two axboxes are created in place of the two ellipses, which the The bearing side of the space-time field can be seen. as a display device, a known combination of frame and dipole antennas as a recording element and an amplitude and phase control element, and their modes are that the two types of antenna be calibrated by means of the mentioned control elements for the same recording of the field sizes. Farther is used when using a single combination of a dipole antenna and a vertical loop antenna ensured that the normal of the frame to antenna and the coincident axis of the dipole antenna once in the direction of the sky wave and then rotated in the direction of their reflected ones. The two antennas are interposed the attenuator and phase rotating elements are connected to the two amplifiers of the radio direction finder, so that on the display screen of the Braun tube one after the other or with sufficiently different switching also at the same time two ellipses appear, which are polarization and bearing side of the space wave so and what they reflect on. It is known that when creating the antenna system of a receiving installation for electromagnetic waves, only precise knowledge of their polarizations and their directions of incidence allows optimal orientation of the antennas. The case now often occurs that an elliptically polarized space wave with the azimuth ρ and the elevation f must be received or bearing at the same time as its reflected. For determining the direction of incidence, arrangements are known (German patent specification 1 080 633) which allow the elevation f to be determined unambiguously and the azimuth ambiguously by the values ρ and ρ f π . The marking of the angle /) in relation to the angle ρ -f π takes place by means of a side determination. It is the aim of the present invention to make arrangements with which the bearing side can be determined for this case of propagation. In Figs. 1, 2, 3, 4 is now the essence of Arrangements according to the invention explained in more detail. It represents F i g. 1 the spatial assignment of an electromagnetic wave and its reflected on the ground 4 ^r to the coordinates of the room. F i g. 2 the block diagram for the basic determination of the polarization and bearing side of the field. F i g. 3 the block diagram for the practical determination of the polarization and bearing side of the field. F i g. 4 shows the block diagram of a further arrangement for determining the bearing side of the field. In Fig. 1 is one with elevation f and any polarization from the azimuth /? wave arriving at the location of the DF antennas. To each wave falling obliquely from above, there is also the one reflected on the ground, which acts like a coherent wave from the elevation - ε , but differs in amount by the reflection factor r and in phase by the angle * from the primary wave. Under these conditions, the total electrical and magnetic field strengths in the Directions of spatial width (() and the reflected space wave (2) are given by the following expressions: