Radar Flashcards
Hvað segir Pulse Recurrence Rate (PRR) þér?
Number of pulses per second
When an operator increases range, PRF becomes __ and pulse length becomes __.
lower, larger
Hver er formúlan fyrir range (Primary radar)?
range (km) = 300,000 / PRF*2
Primary radar operates on the __ technique
pulse
In a primary radar using the pulse technique, the ability to discriminate between targets in azimuth is a factor of
a) Pulse Recurrence Rate (PRR)
b) Beam width
c) Pulse length
b) Beam width
In a primary radar using pulse technique pulse length determines minimum ___ ___.
measurable range.
In a primary radar using pulse technique, PW (Pulse Width or also called Pulse Length) determines
a) maximum range
b) minimum range
b) minimum range
In relation to primary radar, what does the term pulse recurrence frequency signify?
a) The time between each transmission of pulses
b) The number of pulses transmitted per second
b) The number of pulses transmitted per second
For any given circumstances, in order to double the effective range of a primary radar, the power output must be increased by a factor of:
a) 8 b) 4 c) 16 d) 2
c) 16
The theoretical maximum range for an Airborne Weather Radar is determined by the __ ___ frequency
Pulse Repetition Frequency (PRF)
Airborne Weather Radar (AWR) uses ___ radar principles.
primary
The main factor which determines the minimum range that can be measured by a pulsed radar is
a) Pulse repetition rate
b) Pulse length
b) Pulse length
Hvað af þessu notar pulse technique (radar)?
a) Aerodrome surface movement radar
b) Airborne weather radar
c) Secondary surveillance radar (SSR)
d) Aerodrome Surveillance (approach) radar
allt
Moving target indicator eliminates all ___ targets.
stationary
What is the max range of an ATC Long Range Surveillance Radar?
200 - 300 NM
Moving target indicator suppresses all ___ echoes
stationary
In order to penetrate a cloud, a primary radar signal must have
a) a long wavelength
b) High PRF
c) short pulse
a) a long wavelength
Information displayed on a primary radar system is aircraft ___ only.
position
A typical primary pulse radar uses a ___ aerial for
a) Transmission
b) both transmission and reception
directional
Echoes that do not change in distance from antenna (relative speed zero) are dangerous because Moving Target Indicator (MTI)…
eliminates such echoes.
Hvaða græja er notuð til að detecta aircraft not equipped with transponder?
PSR (Primary Surveillance Radar)
What combination gives the best screen picture in primary search radar? Long/short pulse length and narrow/wide beam
short pulse length and narrow beam
In a Terminal Area Surveillance radar, the range is up to __ NM
80
Surface movement radar uses __ band instead of EHF because EHF is absorbed and scattered by __ in the air.
SHF, moisture
Surface movement radar rotates _ times per minute.
60
Hvaða radar er það sem getur stundum greint flugvélategundir?
Surface Movement Radar
Hver er kosturinn við primary radar of a continuous wave transmission as compared with pulse transmissions?
Continuous wave eliminates the minimum target reception range
Which radar system is most used for short range operation? ___ continuous wave
Primary
You are on the runway, there is a thunderstorm in front of you. __ should be off.
PWS (Predictive Windshear System)
Height ring: Can be used to determine that the weather radar is __.
functioning
During a climb, the tilt needs to be decreased to scan for hazardous ___.
clouds
Optimum frequency is __ GHz because the larger water droplets will give good echoes and the antenna can be kept relatively small
10
The aircraft weather radar uses a cosecant radiation pattern uses what mode?
MAPPING
Airborne Weather Radar that has a colour cathode ray tube (CRT), the areas of greatest turbulence are indicated on the screen by
a) large areas of flashing red colour
b) colour zones being closer together
b) colour zones being closer together
Airborne Weather Radar uses a secondary/primary radar in the VHF/SHF band.
primary, SHF
Height ring is an ___ which is produced by side lobes from the aerial of a weather ___.
echo, radar
A pilot can use the height ring to determine if the weather radar is ___.
functioning
Hvað á við um MAP mode í AWR?
a) A chart/map from the navigation database will be indicated
b) Ground/terrain will be indicated
b) Ground/terrain will be indicated
AWR uses a 3 cm wavelength to detect larger ___.
water droplets
Hverju getur þú lent í ef þú notar MAP mode í polar areas?
Mistake the edge of coastal ice off shore for the real coastline
In weather radar the use of cosecant beam in mapping mode enables scanning of a large ground zone producing __ who’s signals are practically ___ of distance.
echos, idependent
Airborn weather radars use a frequency of approximately 9 GHz because the wavelength is such that reflections are obtained only from the ___ water droplets.
larger
To improve the detection of precipitation areas in e.g. thunderstorms, in which the top of the cloud lies at or slightly above the level of flight:
the tilt setting should be higher/lower when the aircraft climbs to a higher altitude
lower
Hvort er meira accurate in bearing and distance?
a) Primary radar
b) Secondary radar (SSR)
a) Primary radar
In the SSR response, the operation of the transponder ident button
a) sends a special pulse after the normal response pulse train
b) sends a special pulse before the normal response pulse train
a) sends a special pulse after the normal response pulse train
Getur hugsað þetta þannig að mikilvægast sé að koma upplýsingunum um staðsetningu og svo auka upplýsingum bætt við aftan á.
With mode-S each aircraft can be uniquely interrogated and identified by using
a) Special Position Identification (SPI) pulse
b) 24 bits address code, giving more than 16 million possible codes.
b) 24 bits address code, giving more than 16 million possible codes.
The two main design functions of Secondary Surveillance Radar (SSR) Mode S are:
a) Air to ground and ground to air data link communications and improved ATC aircraft surveillance capability
b) Collision avoidance using TCAS II and improved long range (HF) communication capability
a) Air to ground and ground to air data link communications and improved ATC aircraft surveillance capability
The maximum range of primary radar depends on
a) Pulse repetition frequency
b) pulse length
a) Pulse repetition frequency
Ímyndaðu þér bara að til að fá meira range þá er sett bara á fast-motion, stutt skot eins og úr hríðskotabyssu.
ATH þetta er maximum range, minimum range ræðst af pulse length.
Hvaða formúlu notar þú til að átta þig á hvað þú þarft að auka power output mikið til að fá t.d. tvöföldun á range?
power output í fjórða veldi
When an operator increases the range on a radar-display, in general
a) The PRF becomes lower and the pulse length larger
b) The PRF becomes higher and the pulse length smaller
a) The PRF becomes lower and the pulse length larger
Ímyndaðu þér bra að þegar range er increased þá er hægt á pölsinu, frequency lower og lengri lengdir. Ímyndaðu þér bara að radarinn fari á slow motion.
In relation to radar systems that use pulse technology, the term Pulse Recurrence Rate (PRR) signifies the
a) number of cycles per second
b) number of pulses per second
b) number of pulses per second
Ef þú ert spurður um hvaða radar equipments noti “pulse technique” hvað er svarið?
held að allir radars noti pulse technique, svo þú myndir velja alla svarmöguleika sem innihalda orðið “radar”.
In a primary radar using pulse technique, he ability to discriminate between targets in azimuth is a factor of
a) beam width
b) aerial rotation rate
a) beam width
descrimination in azimuth er að greina á milli hluta í hvaða stefnu þeir eru.
Best results in radar: Short/long pulse length and wide/narrow beam
short pulse length, narrow beam
