Attenuation of radio waves in the atmosphere is caused by absorption of their energy free molecules of oxygen and water vapor, and also the weighed particles – motes and drops of water. Besides, there is a dispersion of radio waves liquid and firm particles which cause the effect similar to energy absorption.
In the ranges of centimetric and especially millimetric waves intensive absorption of electromagnetic oscillations causes undesirable reduction of range of action of station. Besides, hydrometeors in these ranges can be a source of the intensive reflection which is complicating and completely excluding supervision is more whole.
At impossibility of placement by plane of the main indicator (the block instead of it the additional indicator (the block 4-having the smaller sizes can be installed. In this case in a complete set of station the separate control panel (the block is surely removed
The scheme of electromechanical control of the antenna provides scanning of the antenna in an azimuth and combination of an axis of the directional pattern with the horizon plane (or the set plane) at a list and pitch of the plane on the channel of an inclination.
Width of the directional pattern of the antenna influences range of radar supervision. In process of narrowing of the directional pattern of the antenna its coefficient of the directed action increases and respectively the maximum range of action of RLS increases.
In this case it does not make sense to speak about resolution on a place corner since we project survey RLS which antenna has the kosekansny directional pattern and does not take resolution on a corner place.
At change of polarization of the irradiating fluctuations with vertical on horizontal (when giving 27B on a ferrite rotator of the plane of polarization) the reflector of a special form opaque to waves of this polarization, together with a paraboloid of rotation forms the profile forming the fan directional pattern in the vertical plane.
The onboard radars created on element base of the first generation (electron tubes, volume installation), big dimensions and weight, had small reliability and consisted of a large number of blocks. Transition to element base of the second generation (semiconductor devices and modules) allowed to improve considerably characteristics of a number of knots and blocks.
On the contrary, high precision of counting of angular coordinates and resolution are, as a rule, important for short-range RLS. In such cases it is favorable to use centimetric, and sometimes and millimetric waves as at the general small radius of action of station attenuation of electromagnetic waves in the atmosphere will affect still not too strongly.
The mechanism of formation of the image on the ELT screen is described below. At rotation of the antenna when the edge of the directional pattern coincides with the direction on the purpose, on the answering development radius under the influence of an impulse to the purpose there is a bright point. Besides, there is a series of bright ekvidistantny points under the influence of large-scale impulses. Rotation of the antenna clockwise equivalently to movement of the purpose in the opposite direction. After a complete revolution of the antenna on the screen large-scale rings (an electronic scale of range) are formed, and the purpose will have an appearance of a small arch which angular sizes are approximately equal to the angular width of a beam of the antenna.
For convenience usually consider separately the directional pattern in the horizontal plane and the directional pattern in the vertical plane. Thus pay attention to width of the directional pattern of q.
Sinkhr. – synchronizer; To THEM – the pulse modulator; The microwave oven of the Gen. – the microwave oven generator; AP – the antenna switch; GMI – the generator of large-scale impulses; PRM – the receiver; GR – the development generator; ELT – an electron beam tube; The PROGRAM STATUS WORD – the silsinno-watching transfer; MVA – the mechanism of rotation of the antenna.
The RLS antenna has the fanlike directional pattern, that is narrow in the horizontal plane (width in some degrees or q=3 degree share, and rather wide (tens degrees of Dbobz=35 in the vertical plane. At rotation such antenna provides not only the demanded review in the vertical and horizontal planes, but also measurement of an azimuth.