a wire mesh which is configured to include a plurality of transmitters and a plurality of receivers; and

a fixing part for fixing the wire mesh;

wherein the plurality of transmitters supply electricity to the wire mesh, and

wherein, in response to rain being positioned between a specific transmitter among the plurality of transmitters and a specific receiver among the plurality of receivers, the specific receiver is configured to receive the electricity from the specific transmitter and then transmit the electricity to a measuring part, to thereby allow the measuring part to measure conductivity, wherein the plurality of transmitters in the wire mesh are respectively connected to a transmitter circuit, wherein the plurality of receivers in the wire mesh are respectively connected to a receiver circuit, and wherein one end of the measuring part is connected to the transmitter circuit and an opposite end of the measuring part is connected to the receiver circuit,

wherein the wire mesh includes: a first mesh part comprised of the plurality of transmitters and the plurality of receivers; and a second mesh part comprised of a plurality of heaters,

wherein the first mesh part is characterized in that the plurality of transmitters are arranged in a 1-st circumferential direction or in any direction within a 1-st circumferential threshold angle from the 1-st circumferential direction and that the plurality of receivers are arranged in a 2-nd circumferential direction or in any direction within a 2-nd circumferential threshold angle from the 2-nd circumferential direction, and wherein each of the plurality of transmitters and each of the plurality of receivers are arranged at a right angle to each other or at any angle within a 3-rd threshold angle from the right angle,

wherein the second mesh part includes: 1-st second mesh parts arranged in the 1-st circumferential direction or in any direction within the 1-st circumferential threshold angle from the 1-st circumferential direction; and 2-nd second mesh parts arranged in the 2-nd circumferential direction or in any direction within the 2-nd circumferential threshold angle from the 2-nd circumferential direction, wherein the 1-st second mesh parts and the 2-nd second mesh parts are arranged at a right angle to each other or at any angle within the 3-rd threshold angle from the right angle, and

wherein the wire mesh is characterized in that the wire mesh is in a form of a hemisphere, and in that a 1-st circumferential wire having a longest length on a surface of the hemisphere in the 1-st circumferential direction among the heaters in the 1-st second mesh parts and the plurality of transmitters is arranged in the 1-st circumferential direction, and other wires among the heaters in the 1-st second mesh parts and the plurality of transmitters are arranged in any direction within the 1-st circumferential threshold angle from the 1-st circumferential direction, and in that a 2-nd circumferential wire having a longest length on the surface of the hemisphere in the 2-nd circumferential direction among the heaters in the 2-nd second mesh parts and the plurality of receivers is arranged in the 2-nd circumferential direction, and other wires among the heaters in the 2-nd second mesh parts and the plurality of receivers are arranged in any direction within the 2-nd circumferential threshold angle from the 2-nd circumferential direction.