A turnstile antenna used for reception of weather satellite data on 137 MHz. It consists of two identical dipole antennas at right angles, fed in quadrature. This type of antenna is used because it receives circularly polarized radio waves transmitted by the satellite. Circular polarization is used for satellite communication because it is insensitive to the relative orientation of the transmitting and receiving antenna elements. Alterations to original image: cropped out portions of empty sky to give closeup view, increased contrast.