(1) is not; (2) desired

(1) is not; (2) true

(1) is; (2) desired

(1) is; (2) true

eliminate the need for azimuth slaving.

greatly reduce lateral lobes, consequently concentrating more energy into the main beam.

produce a wide beam for better target detection.

simultaneously transmit weather and mapping beams.

with transmissions of the Meteorological aerodrome Report (METAR)

in VHF transmissions to reduce transmission power.

in HF two-way communication.

with NDB transmissions to reduce the bandwidth

Time.

An amplitude.

A frequency.

Distance.

Altitude is too high.

Aeroplane is below the minimum altitude for line of sight propagation.

The power of the transmitted signal is too weak to be received by the DME station.

Aeroplane is circling around the station.

A continuous wave interrupted with a keyed Morse code ident as used by an NDB.

Amplitude modulated by a speech signal, such as is used for VHF-COM.

Interrupted to transmit the Morse code identification, as used by an NDB.

Amplitude modulated to transmit the Morse code ident, as is used by a VOR.

6 seconds.

3 hours.

3 seconds.

6 minutes.

the solar wind and the gravitation of the Sun, moon and planets.

solar and lunar precession.

Earth and lunar precession.

the lunar wind and the gravitation of the Earth, moon and stars.

It needs a higher elevation than 15° above the horizon.

It needs a higher elevation than 5° above the horizon.

It needs a higher elevation than 55° above the horizon.

It needs a higher elevation than 5° below the horizon.

detect small as well as large cloud formations.

obtain optimum use of the cosecant squared beam.

transmit at a higher pulse repetition frequency for extended range.

detect larger water droplets.