EP0007831B1 - Apparatus for adjusting the azimuth and elevation angles of an electromagnetic wave reflector - Google Patents

Description

The invention relates to the adjustment of wave reflectors, such as those used in particular for radio links, called passive reflectors in the far field.

A passive reflector is said to be "in the far field when its distance to one or the other of the antennas of the radio link is at least equal to 2 D ² / X, D being the diameter or the vertical dimension of the most open large: antenna or passive.

The passive far field reflector is used in the case where the optical visibility between the two active ends to be joined by the radio link does not exist, and where the link budget is such that a reflector of relatively small dimensions makes it possible to obtain a sufficient margin and therefore a good quality of connection.

In the mountains, the passive reflector is used to cross ridges separating two points which are often not far from each other in the horizontal plane. In this case, the use of the passive reflector is advantageous, since it requires practically no maintenance and above all it avoids the construction of a station with active relay in places that are difficult to access.

In the plain, the passive reflector is often used to directly access the telephone exchange in a city when it is not directly visible from the other end of the radio link. Such an arrangement avoids the construction of a terminal radio station and the transfer of signals received by cables to the telephone exchange.

Such a passive reflector usually consists of a non-deformable metallic flat panel (generally made of aluminum alloy which combines lightness, good conductivity and unalterability over time) installed on a pylon with the interposition of support means adjustable along two perpendicular pivot axes. , one to be able to obtain the site and the other the desired azimuth.

It is in particular necessary to precisely adjust the orientation in azimuth and in site of such a passive reflector in order to obtain the best efficiency, and this constitutes a problem whose solutions hitherto proposed prove to be costly and time-consuming. enforce. A calculated predetermination of the site for the setting may be suitable, while an associated azimuth setting with the compass gives way to trial and error in search of the best performance which are long and immobilize maneuvering personnel.

It has also been proposed to use aids in the form of infrared or laser transceivers which are costly, difficult to install on the pylons and whose energy supply is an easement all the more important as the distances emitter- receiver are high.

There has also been proposed in publication FR-A-2,350,741 a device for adjusting the orientation in azimuth and in elevation of a wave reflector, comprising a fixing plate mounted on the reflector and carrying a kind of compass with two sight rods in the direction of the transmitter and of the wave receiver, and which is arranged so that the bisector of the angle of the two rods remains perpendicular to the surface of the reflector. These rods can be provided with a telescopic sight.

The adjustment with such a device can only be done by successive approximations after visual evaluation of the angles in question and it remains relatively long and imprecise in the absence of angle measurements that can be made relative to the vertical and horizontal plane and in reference at elevation and azimuth angles which can be calculated topographically and lead to rapid adjustment precision.

The subject of the present invention is a relatively inexpensive device making it possible to advantageously establish such settings quickly and easily.

Essentially, for this purpose, the device according to the invention for adjusting the orientation in azimuth and in elevation of a wave reflector, in particular for radio links, comprising a fixing plate on a reference surface of the reflector and an optical telescopic sight in the direction of the transmitter and the wave receiver, is characterized in that it comprises a cradle secured to the plate (1) and supporting a pivoting element movable in the adjustment site plane, means for reading the relative angular position between the cradle and the movable element in elevation, the latter supporting a movable element in azimuth mounted rotating around an axis perpendicular to the pivot axis in elevation, means for reading the relative angular position in azimuth between the movable element in elevation and the movable element in azimuth, said telescopic sight being mounted movable in elevation on said movable element in azimuth, means for adjustable fixing of the plate on the reflector r and a spirit level carried by the movable element in azimuth to adjust the verticality of the axis of pivoting in azimuth of the device, said spirit level then serving to bring the reflector to the site displayed by jamming of the bubble being displacement of the reflector in elevation, the reflector being brought into the desired azimuth by coincidence of aiming with the telescope at an azimuth angle calculated with the direction of the emitter or receiver of reflected waves.

• la figure 1 est une vue schématique illustrative de paramètres entrant en ligne de compte dans le réglage d'un réflecteur d'ondes entre une station émettrice et une station réceptrice ;
• la figure 2 est une vue en élévation, avec coupe partielle suivant II-II de la figure 3, du dispositif selon l'invention ;
• la figure 3 est une autre vue en élévation du dispositif suivant la flèche III de la figure 2, avec coupe partielle suivant III-III.

An embodiment and implementation of a device for adjusting the orientation of a wave reflector according to the invention is described below by way of example and with reference to the appended drawing in which:

• Figure 1 is an illustrative schematic view of parameters relevant to the setting of a wave reflector between a transmitting station and a receiving station;
• Figure 2 is an elevational view, partly in section along line II-II of Figure 3, of the device according to the invention;
• Figure 3 is another elevational view of the device along arrow III of Figure 2, with partial section along III-III.

In the diagram of Figure 1, there is shown in R on a scale considerably enlarged compared to the rest of the figure, a reflective panel intended to serve as a passive relay between two stations Si and S ₂ - We have designated by C a point of the panel R corresponding to the fixing area on the latter of the device which is the subject of the invention, and the projection of C has been designated by O in a horizontal plane which is that of the x and y coordinates of the map of the places, the altitude in Z supposed to be that of the station S ₂ (S ' _i being the intersection of CS, with the same plane) so that θ ₁ and θ ₂ correspond to the elevation angles under which the reflector is seen from from stations Si and S ₂ - This reflector must be adjusted in azimuth perpendicular to the bisector CI of the angle Si CS ₂ and in elevation along the angle 6 ₃ equal to the angle θ ' ₃ under which it would be seen from from point I.

les signes donnant le sens de Δα, et θ₁ et θ₂ pouvant être mesurés ou calculés à partir des données topographiques des points C, S₁ et S₂.It should be noted that the projection Ol of the bisector CI on the horizontal plane is not the bisector Ol 'of the angle S ₂ OS' ₁ equal to 2a (measurable on the map or calculable) and makes an angle with it Δα. The calculation of the site angle θ ₃ of the reflector and of Δα, the utility of which will be seen below, gives the following results:

the signs giving the meaning of Δα, and θ ₁ and θ ₂ can be measured or calculated from the topographic data of points C, S ₁ and S ₂ .

The orientation adjustment device shown in FIGS. 2 and 3 comprises a plate 1 with a square profile on which two spaced U-shaped flanges 2 and 3 are fixed by screws, matching said square profile and one of the branches of which is crossed by a threaded rod 4 provided with an operating button 5 and a clamping shoe 6 intended to allow the fixing of the plate 1 in a position where it marries the upper edge of the reflective panel R, or even a localized reference surface of the flatness of it.

The flanges 2 and 3 are also each provided in the central branch of the overlapping U of the panel they form, with a screw 7 with pad 8 freely passing through the plate 1 and which is provided with an operating button 9 in view to allow, as will be seen, an adjustment of horizontality of the device in the plane of the reflective panel.

On the upper wing of the plate 1 is fixed by screw a cradle 10 pivotally supporting along the arc of the joint plane 11 (see fig. 2) to which corresponds a virtual pivot axis P, an element 12 movable in the adjustment site plan considering the device attached to the reflector panel. This element 12 can be moved around the virtual axis P using a manual button control 13 driving a usual mechanism not shown, with tangent screw secured to said button and journalling in the cradle 10 as well as cooperating with an arc of tangent wheel of center P integral with said element 12. The angular position of the latter relative to the cradle 10 can be read by means of a graduation such as 14 formed on one of the parts 10-12, the other of which bears a reading vernier 14a.

Finer divisions of this graduation may alternatively be provided on the fixed bearing of the aforementioned tangent screw, opposite the adjacent edge of the button 13 provided with a reading index.

On the element 12 is mounted rotating about an axis perpendicular to the pivot axis in elevation P and represented geometrically by the axis V, an element 15 constituting a movable element in azimuth. This element 15 can be moved around the virtual axis V by means of a manual control with a button 16 driving a usual mechanism, not shown, with tangent screw secured to said button and rotating in the element 12 as well as cooperating with a wheel. tangent of axis V integral with the element 15. The angular position of the latter relative to the element 12 can be read using a peripheral scale such as 17 provided on one of the parts 12-15, of which the other wears a reading vernier 17a. On the element 15 is fixed by screw a yoke 18 between the rising branches of which is articulated support, by the axes 19 and 20 of which it is integral, a collar 21 for tightening a telescopic sight 22, movable in elevation between the branches of the yoke 18 and maneuverable using a button 23 secured to said axis 20.

In the center of the flat base of the yoke 18 is fixed by screw a spirit level 24 of precision.

With such a device, the adjustment of a reflective panel can thus be carried out as follows:

The plate 1 is brought into position on the upper edge of the panel, whose flatness it follows by its drooping wing and, before being immobilized by tightening on the panel of the pads 6, the horizontality of the device in the plane of the panel is ensured by rotating the movable element 15 at a right angle relative to its position in FIGS. 2 and 3, so as to bring the bubble level 24 in parallel with the upper edge of the panel, so that by wedging the bubble between its marks by using the screws 7 with support pad 8 the desired horizontality is established, the element 15 being able to be brought for this operation approximately vertically. The plate can then be immobilized using the pads 6.

The fixing of the device being thus made on the reflective panel, the first step is to adjust the reflective panel in elevation, by bringing the movable element 15 in the state shown in drawing of perpendicularity of direction of the bubble level 24 with respect to the plane of the panel, which can here correspond to a coincidence of zero of the graduation in azimuth 17 with the corresponding vernier 17a. By then displaying with precision the site 0 ₃ previously calculated, using the manual button control 13 and the site graduation 14 with reading vernier 14a, it is easily understood that by moving the reflective panel R into site in acting on its support means so as to wedge the bubble of level 24 between its marks, we will have given the panel the precise site angle displayed on the site scale.

We will then proceed to the azimuth adjustment, noting in this respect that the previous operations controlled at the spirit level 24 had the effect of ensuring the verticality of the axis V of the element 15 movable in azimuth, so that the '' can then be measured by azimuth aiming using the telescope 22 movable in site the real angle 2a made by the azimuths C5 ₁ and CS ₂ of the antennas of the two stations S ₁ , S ₂ , also determinable on the map of places with sufficient precision to allow the calculation of the correction angle Δa mentioned above.

From the value of a resulting from sightings made on the antennas of stations Si and 5 ₂ , to which it is necessary to add or subtract the angle Δa depending on whether one will proceed by setting sighting on the antenna of the station Si or 5 ₂ , and by displaying the angle a ± Δa using the manual button control 16 and the azimuth graduation 17 of the element 15, it is easily understood that it suffices to then move the reflective panel R by acting on its support means so as to allow the optical sighting axis of the telescope 22 to be brought to the antenna of the station Si or S ₂ chosen, so that the reflective panel is actually oriented in the desired azimuth which is that of the right 01 of figure 1.

Reiterations can be provided in elevation and azimuth to refine the adjustment that the device according to the invention makes it possible to obtain much more simply and quickly than with the methods hitherto known.

The field of use of such an optical device is sufficiently wide for current applications in radio links, it should be noted, by way of indication, that with a magnification scope 20 for example it is easy to make sights up to 30 km, which can be increased to 60 km by installing a flashing mirror on the antenna of the station or stations considered.

Claims (2)

1. An apparatus for adjusting the azimuth and elevation angles of an electromagnetic wave reflector, in particular for microwave links, comprising a fixing plate (1) for securing to a reflector reference surface and an optical telescope (22) for sighting in the direction of the wave transmitter and receiver, characterized in that it comprises a cradle (10) fixed to the fixing plate (1) and carrying a swivelling element (12) which can move in the adjustment elevation plane, means (14, 14a) for reading the angular position of the cradle (10) relative to the element (12) movable in elevation, with this latter carrying an element (15) which can move in azimuth and which rotates round an axis perpendicular to the elevation swivelling axis, means (17, 17a) for reading the angular position in azimuth of the element (12) movable in elevation relative to the element (15) movable in azimuth, the said sighting telescope (22) being fitted to be movable in elevation on the said element (15) movable in azimuth, adjustable means (2 to 9) for securing the fixing plate (1) to the reflector (R) and a spirit or air level (24) carried by the element (15) movable in azimuth for adjusting the verticality of the azimuth swivel axis of the device, with the said spirit level (24) being used subsequently to bring the reflector (R) to the displayed elevation by keeping the air bubble centred whilst the reflector is being moved in elevation, the reflector being brought to the required azimuth by getting the sight line of the telescope (22) to coincide at a calculated azimuth angle with the direction of the reflected waves transmitter or receiver.

2. The device according to claim 1, characterized in that the said adjustable fixing means comprise two clamps (2, 3) placed to straddle a top edge of the said reflector (R) reference surface and each comprising a support adjustment screw (7, 8) bearing on the said edge and used to establish the horizontality of the device with respect to this edge.

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