Weather radar and weather observation method

A weather radar comprising:

• an antenna unit of an active phased array system in which a plurality of antenna elements configured to transmit a radar pulse and receive a reflected pulse are arranged in a vertical direction;
• a transmission beam formation unit configured to divide an observation range in the elevation angle direction into a plurality of observation elevation angles, subdivide each observation elevation angle into a plurality of regions, assign each of transmission frequencies of radar pulses different from each other to each set of regions not adjacent to each other, and form a plurality of fan-shaped transmission beams in the plurality of regions in the elevation angle direction at pulse repetition intervals (PRIs);
• and
• a reception beam formation unit configured to form a plurality pencil-shaped reception beams for each of the plurality of regions.

A weather observation method used for a weather radar including an antenna unit of an active phased array system in which a plurality of antenna elements configured to transmit a radar pulse and receive a reflected pulse are arranged in a vertical direction comprising:

• dividing an observation range in the elevation angle direction into a plurality of observation elevation angles;
• subdividing each observation elevation angle into a plurality of regions;
• assigning a set of a plurality of regions not adjacent to each other to a pulse repetition interval (PRI);
• forming a fan-shaped transmission beam in the elevation angle direction for each of the regions in the set;
• and
• forming a plurality of pencil-shaped reception beams for each of the plurality of regions.

A weather observation method used for a weather radar including an antenna unit of an active phased array system in which a plurality of antenna elements configured to transmit a radar pulse and receive a reflected pulse are arranged in a vertical direction comprising:

• dividing an observation range in the elevation angle direction into a plurality of observation elevation angles;
• subdividing each observation elevation angle into a plurality of regions;
• assigning each of transmission frequencies of radar pulses different from each other to each set of regions not adjacent to each other;
• forming a plurality of fan-shaped transmission beams in the plurality of regions in the elevation angle direction at pulse repetition intervals (PRIs);
• and
• forming a plurality pencil-shaped reception beams for each of the plurality of regions.