Precision approach radar

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to a precision approach radar, and relates to the precision approach radar which follows by catching a target especially by two-dimensional electronic scanning. [Description of the Prior Art] The former and this kind of precision approach radar (it calls PrecisionApproach Radar and following PAR), A tailing scan is performed, searching for a target by the search mode which scans transmitting beam 300 formed as a pencil beam according to an order that search plane 200 limited as shown in Drawing 3 (a) was able to be decided, and it is target A, What is called TWS that follows B etc. Search tailing of the target is carried out with (Track While 5can) the method. Drawing 3 explains the beam scanning method of PAR. Search mode scans a pencil beam toward the bottom from the upper left of a search side, and it scans it to a right end, shifting the 2nd and the 3rd beam direction on the right from the left next. tailing mode turns a beam for eye Munakata obtained in search mode -- between search modes (i.e., the case of Drawing 2 (a)) -- the period of one search -- two targets A and B -- every 3 times -- tailing -- scanning -- it carries out. The time distribution in a transmitting beam scan is shown in Drawing 3 (b). A tailing data rate shows the cycle of tailing for the time which one search takes a search data rate again. Since tailing may separate when a tailing data rate becomes late, it is necessary to secure a data rate to such an extent that it does not separate. If a search data rate becomes late, in order that capture of a target may be overdue, a suitable data rate needs to be set up. In order to determine a data rate, in consideration of a field of search, the degree of beam step angle, and the pulse hit count that transmits between 1 beam positions, the data rate of a search and tailing needs to serve, and it is necessary to take Fit into consideration, and is determined as the optimal value which took these conditions into consideration. [Problem(s) to be Solved by the Invention] Since the conventional PAR mentioned above is using the high frequency of about 9 GHz, Airport surveillance radar (Air-port 5urveillance Radar) following ASR -- calling -- there is a fault that attenuation by rain is large and detection distance contracts sharply compared with other air-traffic control radars, such as a secondary surveillance radar (it calls 5econdry 5urveillance Radar and following SSR), at the time of rain. In order to improve detection performance, there is the method of raising an initial pulse hit count, but when an initial pulse hit count is raised, there is a fault that a necessary data rate is not securable. [Means for solving problem] A precision approach radar of the present invention comprises: A coordinate transformation means which inputs position information about distance, a direction, and an altitude of a target airplane acquired by an airport surveillance radar and a secondary surveillance radar which are put side by side in an airport with a precision approach radar, and changes this position information into coordinate data which makes an installed position of a precision approach radar the starting point, A transmitting beam inclination means to search for an angle of direction and an angle of site required for making a target airplane point to a transmitting beam of a Precise measurement penetration lake from coordinate data changed by the above-mentioned coordinate transformation means, and to make a target airplane point to a transmitting beam based on these angles of direction and an angle of site. [Example] Next, the present invention is explained with reference to drawings. Drawing 1 is a block diagram showing the composition of one example of PAR of the present invention. PAR of the example shown in Drawing 1 is provided with the same transmission section 6 as the usual PAR besides coordinate transformation part 1 which constitutes a coordinate transformation means, data conversion part 2 which constitutes a transmitting beam inclination means, tailing treating part 3, and beam control part 4, receiving part 7, indicator 8, and directional coupler 9, and is constituted. Next, operation of the example of Drawing 1 is explained. It is inputted into coordinate transformation part 1, the difference of a setting position between ASR, SSR, and PAR is amended here, and ASR and SSR data (distance R' direction theta to a target, 2', altitude H') are outputted to back data conversion part 2 changed into the data at the installed position of PAR, and an installation altitude. In data conversion part 2, angle-of-site theta2L is called for by an operation from distance R and altitude H to a target, and it is outputted to tailing treating part 3 with angle of direction thetaA2. In tailing treating part 3, it asks for the beam number which shows the position of an antenna beam from angle-of-direction theta8□ and ascending vertical angle theta8L, and outputs to beam control part 4. Beam control part 4 generates the Transfer phase code of antenna 5 corresponding to a beam number, and turns it in the direction of the target which caught the antenna beam by ASR and SSR. Transmission section 6. receiving part 7 transmits and receives via directional coupler 9, and R2thetaAZ+theta8L is displayed on indicator 8 in a specific form. Drawing 2 (a) A beam scan and time distribution of the present invention are shown in (b), respectively. It is possible to raise the initial pulse hit count emitted to one target, maintaining the same data rate as tailing day Sauce- T+ of former PAR of Drawing 3, since PAR was not searched as shown in Drawing 2. [Effect of the Invention] As explained above, in the present invention, [ for the purpose of a beam ], ASR and SSR perform a search of a target and PAR only follows with position data of ASRSSH with a larger detection distance with little [ and ] attenuation by rain than PAR. Therefore, time which a search takes is applied to tailing, it becomes possible to raise an initial pulse hit count at the time of tailing, and there is an effect which can heighten detecting ability remarkably. Also when the case where an airplane small besides the improvement in detecting ability at the time of rain is guided from a distant place, and strong electronic disturbance are received, it is effective in the ability to raise detecting ability remarkably.

[Brief Description of the Drawings]

The explanatory view and Drawing 3 showing time distribution (b) of a beam scan (a) and control processing are an explanatory view showing time distribution (b) of the To *-Beam scan (a) of the conventional PAR, and control processing. [ in / in the block diagram and Drawing 2 in which Drawing 1 shows the composition of one example of PAR of the present invention / the example of Drawing 1 ] 1 ...... A coordinate transformation part, 2 ...... A data conversion part, 3 ...... [ ...... A transmission section, 7 / ...... A receiving part, 8 / ...... An indicator, 9 / ..... A directional coupler, 100 / ...... PAR1200 / ...... A search plane, 300 / .... Transmitting beam ] A tailing treating part, 4 ...... A beam control part, 5 ...... An antenna, 6