scope:

The present document specifies technical characteristics and methods of measurements for S band meteorological radar systems intended for the surveillance and classification of hydrometeors with the following characteristics:

• Operating in the following frequency range:

- 2 700 MHz to 2 900 MHz.

• Utilizing unmodulated pulses or phase/frequency modulated pulses also known as pulse compression.

• The maximum output power (PEP) does not exceed 1 MW (i.e. 90 dBm).

• The transceiver antenna connection and its feeding RF line use a hollow metallic rectangular waveguide.

• The antenna rotates and can be changed in elevation.

• The used waveguide is WR284/WG10 waveguide according to IEC 60153-2 [i.2] with a minimum length between the output of the transmitter and the input of the antenna of 2 886 mm (20 times the wavelength of the waveguide cut-off frequency).

• The antenna feed is waveguide based and the antenna is passive.

• The orientation of the transmitted field from the antenna can be vertical or horizontal polarized or it can be both simultaneously.

• At the transceiver output an RF circulator is used.

NOTE 1: Since at the transceiver output an RF circulator is used, it is assumed that the transceiver characteristics remain independent from the antenna.

NOTE 2: According to provision 5.423 of the ITU Radio Regulations [i.7], ground-based radars used for meteorological purposes in the band 2 700 MHz to 2 900 MHz are authorized to operate on a basis of equality with stations of the aeronautical radio navigation service.

NOTE 3: Further technical and operational characteristics of meteorological radar systems can be found in Recommendation ITU-R M.1849-1 [i.3].

NOTE 4: The relationship between the present document and essential requirements of article 3.2 of Directive 2014/53/EU [i.1] is given in Annex A.