SIS_MASI_M3

In the Continuous Wave radar transmission method, which of the following target information is/are provided by the Doppler effect?. Speed of the target. Relative bearing of the target. Range if the frequency is modulated FMCW. Presence of the target.

A radar set with a PRF of 1,000 pulses per second and an antenna rotation rate of 15 rpm produces what maximum number of pulses per degree?. 2.7. 3.6. 11.11.

For a pulsed radar, the maximum unambiguous range depends on: The pulse repetition frequency (PRF). The doppler shift of the received signal. Speed of light. Pulse repetition period.

What is the main advantage of HPRF radar: the ability to detect nose and tail radar targets, also in side lobes clutter. the ability to detect and track ground targets. The ability to detect high speed targets.

Frequency-modulated radars transmit a wave that continuously changes in frequency about a center frequency. Using frequency modulation, the range to a target is determined by using which of the following methods?. by comparing the velocity of the received energy with the velocity of the transmitted energy. By measuring the Doppler shift that occurs in the returning signal. By comparing the magnitude of transmitted pulses with the magnitude of the returned pulse.

Airborne Radars require accurate aircraft navigation data for: Establishing the CFAR threshold. compensating noise in tracking due to own aircraft movements. inertial stabilization of the antenna / automatic tilt control. SAR computations: accurate and low latency position data. Antenna inertial stabilization (horizon) / Automatic Tilt Control. Compensation of echoes (receiver): reduce noise in tracking. Display / north stabilization. Stabilizing the antenna rotation with respect to inertial reference (horizon).

Select which of the following statements is correct. The waveguides are mainly used for conducting high power pulses from the transmitter to the antenna. The best radar antenna configuration for convering 360 degrees around the aircraft is nose-mounted. belly mounted or top mounted.

Which of the following radar components allows the use of one antenna for both transmitting and receiving radar energy?. Synchronizer. Mixer. Duplexer. Circulator.

In a radar without monopulse channels, decreasing the waveguide run between the circulator and the antenna: Reduces only the losses of the received echo. makes necessary increasing the waveguide run between circulator and receiver, to compensate. Allow sweak echoes to pass with negligible attenuation. blocks any signal strong enough to damage the receiver.

ISAR is a radar mode used mainly: In fighters, to discriminate very near targets. To detect very big ships when sea state is very low. To detect small targets when sea state is high using the ships movement.

Which of the following flight conditions are optimal for SAR image generation?. straight and level flight, high constant speed, perpendicular to the target. straight and level flight, high constant speed, direct to the target. orbit (circular) flight path centred in the target, maximum roll of 5°.

In AESA architecture Radars, which of the following statements are true?. The integration is much easier than in classic architecture radars. The TRM matrix is very demanding in terms of cooling. There is no transmitter, but there is one receiver. There is no single signal generator (transmitter).

Select the correct answer(s): the waveguide runs …. should be always pressurized, using dedicated compressors. must have a minimum pressure differential with respect to cabin air. should be designed minimizing the number of joints, bends, and turns, to reduce insertion loss. Admit structural stress, so they can be support to support other structures in the airframe. Must have a minimum air density, to avoid arcing effects during radar transmission.

Choose in which type of object the contribution to RCS due to creeping wave is more important. Cylinder. Sphere. Disk.

Consider a perfect electric conductor (PEC) plane of dimensions 10x10meters at 10GHz. Mark as true or false the following statements: Its RCS is approximately the same than the RCS of a PEC plane of dimensions 20x20 meters at 5 GHz. Its RCS is approximately half of the RCS of a PEC plane of dimensions 20x20 meters at 5 GHz. Its RCS is approximately double of the RCS of a PEC plane of dimensions 20x20 meters at 5 GHz. Its RCS is approximately four times lower than the RCS of a PEC plane of dimensions 20x20 meters at 5GHz.

Consider a perfect electric conductor (PEC) circular cylinder of radius equal to 1 meter and 10 meters long at 10GHz. Mark as true or false the following statements: Its RCS is approximately double of the RCS of a PEC cylinder of radius equal to 2 meters and 10 meters long at 5GHz. Its RCS is approximately the same of the RCS of a PEC cylinder of radius equal to 2 meters and 10 meters long at 5GHz.

Consider a sphere of radius equal to 1 meter at 10GHz. Mark as true or false the following statements: Its RCS is approximately the same than the RCS of a PEC sphere of radius equal to 1 meter at 5GHz. Its RCS is approximately half of the RCS of a PEC sphere of radius equal to 2 meters at 5GHz. Its RCS is approximately the same than the RCS of a PEC sphere of radius equal to 2 meter at 5GHz. Its RCS is approximately double of the RCS of a PEC sphere of radius equal to 2 meters at 5GHz. Its RCS is approximately a quarter of the RCS of a PEC sphere of radius equal to 2 meters at 5 GHz.

Mark as true or false the following statements relative to the frequency dependence of RCS due to specular scattering (reflection) of several canonical scatterers (assuming optics regime): Trihedral f3. Diedral f2. Plate f2. Circular cylinder f2. Sphere f. Curved edge f1. straight edge f1. Corner f2.

The pulsed primary radar when using a non coherent source like a magnetron. Is ambiguous in the range determination. Allows the measurement of th Doppler frequency. Does not need a duplexer. Has a range resolution on depending on the signal bandwidth. Has a range resolution non depending on the signal bandwidth. Has a range resolution depending on the pulse duration. Allows the measurement of the time-of-flight/round-trip time. Allows the measurement of the range.

In an Active Electronically Scanned Array (AESA). The antenna can be aimed at the target without movement. The antenna has a broad radiation pattern. There is not a single signal generator but an array of TRMs (Transmitter-Receiver Modules). There are no motors or mechanics. There are no waveguides / RF lines. There are many transmitter-receiver modules.

In a pulsed Doppler radar. The radial speed measurement is ambiguous. The range measurement is ambiguous. Monopulse techniques can not be applied. A coherent transmitter is required.

What are typical zones of an aircraft on which traveling waves are excited with vertical polarization? It is assumed the aircraft is on level flight. Vertical Stabilizer and rudder. Horizontal stabilizer. Wings. Nose.