Module 1 Flashcards
Which time period saw the most significant innovation in radar technology?
During World War 2
The First aircraft radar detection occurred in
1930
Primary radar is the same as surveillance radar. T/F
True
Aircraft without transponders are _____ to secondary radar.
invisible
What is the relationship between primary and secondary radars in ATC?
Together they provide a complete picture of the air traffic.
What is detection?
The determination that a target is present.
What is Ranging
The determination of the distance to an aircraft in flight by the measurement of elapsed time of the return echo
What is Search
Looking for aircraft within a specified area. Search radars normally determine the range and azimuth of aircraft detected in the area of interest
Height Finding
The determination of the height of an airborne aircraft. The ARSR-4 provides 3D capabilities along the U.S. borders
Velocity Measurement
Radial velocity and even ground speed of aircraft can be determined via software analysis of sets of detection data associated with range and azimuth data.
Track-While-Scan
A software operation that generates tracks for various aircraft by associating target reports from successive scans (antenna rotations). It remembers the last known and next expected location of an aircraft
Azimuth
Determined from position data provided by the antenna of its current direction.
ARSRs operate on which frequency band
L Band
Who discovered electromagnetism and the electric current in 1831
Michael Faraday
What is another name for primary radar
Surveillance Radar
What is the advantage of primary pulsed radar over CW radar
It provides more accurate 2D information
What is another name for secondary radar?
Air Traffic Control Beacon Interrogator
What is the basic difference between primary pulse radar and secondary pulse radar
Primary radar does not need target cooperation
Which frequency does the secondary radar interrogation pulse use?
1090 MHz
What is a disadvantage of secondary radar
The transponder can be disabled.
What is determined from positional data provided by the antenna of its current direction
Azimuth
What is the term for radar looking for aircraft in a specified area
Search
What is the distance to an aircraft in flight as measured by the elapsed time of the return echo?
Ranging
ASR operates in which frequency band?
S Band
TDWR operates in which frequency band?
C Band
what is determined by measuring elapsed time between pulse transmission and the returned echo.
Range
what is a radar’s ability to receive HF radio waves reflected off physical objects.
Detection
The FAA primarily uses radar to
detect aircraft with accurate range and azimuth
What radar uses Moving Target Detector (MTD) processing
ASR-9
What radar is also known as DASR
ASR-11
What radar provides weather information in the terminal environment
TDWR
What radar monitors runways and taxiways for obstructions
ASDE-3A
What radar combines an SMR with an MLAT system
ASDE-X
What system determines aircraft azimuth using monopulse direction finding techniques
MODE-S
What system provides secondary data to the ASR-11.
Monopulse Secondary Surveillance Radar(MSSR)
What system tracks aircraft using GPS
ADS-B
What makes up the heart of the radar system.
frequency generator/synchronizer
what radar component can detect returned target echoes
Antenna
what can can route the received echo pulse into the receiver’s front end
Waveguide
what program allows radars remaining in service to be modernized
Service Life Extension Program
What system replaced the replaced the ASR-7/8.
ASR-11
Which radar system provides a fail-soft operation
ASR-11
what radar system has both an omni-directional antenna and a directional antenna.
ATCBI-5
what determines a target’s location by triangulating the time and distance measurements between radar signals.
WAM
What routes the transmitted pulse to the antenna
Waveguide
what does the frequency generator/synchronizer generate
carrier frequency and timing signals
what is one of the oldest types of displays used in radar
A-Scope
what would be the secondary function for FAA radars to detect
weather phenomenon
The ______ of electromagnetic energy off of physical objects allows radar target detection.
reflection
If a returning echo is strong enough, a(n) _____ will detect it
Antenna
what is is the calculated distance from the radar to the target.
Range
Range is _______ the total distance a sound pulse travels
half
Slant range is the _______ between a radar and the target.
direct line-of-sight
what is is the length of time required for a waveform interval to repeat
period
The ________ and the period are reciprocals of each other.
pulse repetition frequency
The _____ is the fraction of time during which a pulse is active
Duty Ratio
What is an isotropic source
A source that radiates equally in all directions
Electromagnetic radiation in free space travels
At the speed of light
Power density is the _____ radiated by the isotropic source divided by the area of the sphere.
total power
When referring to propagation velocity, what is pulse length
The physical distance between the leading and trailing edge of a propagating pulse
When referring to propagation velocity, what is the pulse duration?
The time duration between the leading and trailing edge of a pulse
The pulse length ______________ as the wave front travels through space
does now vary
Power density is the total power radiated by the isotropic source divided by _________.
Watts
If the power generated during pulse transmission is constant, in an isotropic antenna it is distributed ______________ over a spherical wavefront.
equally
Antenna gain is the ratio of _______ delivered to the target, by the antenna to the power density that would have resulted in the same location from the isotropic transmitter.
maximum power density
Antenna gain is NOT affected by a change in ________.
aperture*****
What is the physical aperture of a radar antenna
Area across the reflector’s opening when viewing the antenna head-on
What is the effective aperture value in a 100% efficient antenna
The physical aperture value
The power extracted from the returning echo wavefront as it strikes the radar antenna is directly proportional to the ________.
effective aperture
antenna gain
radar cross section
Where does most of the power obtained by the antenna go?
Receiver
What is antenna gain?
The power density delivered to a target from an antenna compared to an isotropic antenna
Which type of beam gives lower antenna gains
Wider
What is necessary to calculate antenna gain
Area of the beam
many degrees are in each radian?
57.296
What is the “cone of silence
The space above the radar which doesn’t detect aircraft
RF energy is visualized with the _____ and ______ as its boundary(ies) and the _____ as its length
horizontal and vertical beamwidths, pulse width
Bursts of RF energy are approximately bounded by lines defining the __________ of the system.
horizontal and vertical beamwidths
A radar system’s range resolution measures how well the system can distinguish between two targets at the ______.
same azimuth at slightly different ranges
Targets close enough in range for the radar to only register one pulse return for that position per PRT are __________.
Unresolved
A radar receiver’s basic function is to _____.
amplify and detect returned signals
Along with Boltzmann’s constant, the _____ is needed to calculate input noise magnitude.
temperature of space
The temperature of space (TK) is generally assumed to be _____ K
1.38 x 10-23
Why does a radar system operating on the Earth’s surface have an immediate range disadvantage compared to a radar operating in free space?
The Earth’s atmosphere
What causes the radar horizon to be farther away than the optical horizon
Curvature of the Earth
The length of bursts of RF energy is determined by the _________ of the system
pulse width
What causes the returning echo signals from two targets at the same azimuth and close range to merge and become one continuous echo
Pulse length
The minimum required separation in range permitting individual target detection is the __________
range resolution of the radar system
Thermal agitation is the _____ movement of electrons.
random
If the signal input power is _____ the noise input power, the signal will be masked by noise. Select all that apply.
Less than
_____ is the receiver’s ability to detect weak signals.
Receiver sensitivity
_____ is the weakest signal that produces visible receiver output
Minimum discernable signal
What does clutter refer to
Unwanted echo returns
What is the reference input for MTI and MTD detection circuits
COHO frequency
Synchronizers on newer FAA radar generate ________ for nearly every operation in the system.
control and timing signals
What reports and diagnoses synchronizer malfunctions
SBCs (Single Board Computers)
Synchronizers create timing signals that let the processors know when to start _____.
testing cycles
Error messages from the BIT processes may be sent to the _________. (2 answers)
MDT (maintenance data terminal) and RMS (remote monitoring system)
In a synthesis-type radar system, the _______ frequency is created by combining the ______ frequencies through addition or subtraction
transmitter, STALO (Stable Local Oscillator) and COHO (Coherent Oscillator)
Since STALO _______ is so critical, it is checked as part of routine maintenance checks in most FAA radars.
stability
Basic timing signals, clocks, gates, and triggers come from _______
COHO
________ provide(s) RF trigger pulses to the transmitter and display equipment
Basic synchronizer systems**
What are benefits provided by modern radars that write timing sequences into memory devices (PROMs, ROMs, RAMs)? 2 answers
It is easier to add new functions to the system and It is easier to make timing adjustments to existing functions
Troubleshooting _____ requires determining the path missing its signal and following that signal to its point of failure
analog radar systems
- What is the diagnostic software tool that can pinpoint faults quickly and accurately?
BIT/FIT
BIT can be used to _______. 2 answers
pinpoint faults quickly and accurately and maintain system operations at the proper levels
How did the controller communicate with pilots for manual traffic air control
Colored flags
What was the main problem with manual air traffic control
Pilots could not see the controller and received mixed communications when multiple planes were in the controller’s view
A “blip” on the ____ indicates the aircraft’s position in the terminal area
PPI (Plan Position Indicator)
What was the first total automated tracking system
ARTS (Automated Radar Terminal System)
The ____ system links the ARTCC, ATCT, and TRACON environments to distribute information between facilities.
FDIO (Flight Data Input/Output)
What does a surveillance radar system used by the FAA measure
A target’s range and azimuth
In an ______, the sweep starts at one edge and goes to the other edge
A-scope display
The _______ presents the range and azimuth of a target
PPI
How does a PPI CRT sweep
From the center to the edge of the tubeQ
______ mixes analog video and digital signals, converting them into a raster type output
DBRITE (Digital Bright Radar Tower Equipment0
What is one of the primary reasons why raster scan systems have replaced PPI
High-light environments
What are the two types of non-CRT displays used by the FAA
Plasma and LCD
What does using non-CRT displays eliminate the need for
Deflection yokes, high voltage power supplies, focus, and convergence
What allowed controllers to interact directly with the aircrafts in range of the airport while providing pilots with a method to state their intentions while in flight?
Two-way radios
What was the problem with VFR
Congestion made it difficult to see the controller
Today, the TRACON provides ATC services from the airport to _____ miles away, from the ground up to _____ feet.
between 30 to 50; 10,000
What was a shrimp boat
A block periodically moved on an airspace map by a controller as updates were received from the plane
What software sends out departure, over-flight, and arrival strip messages to Towers or TRACONs at the appropriate time?
FDP (Flight Data Processing)
Range position is determined by ____. Therefore, display devices indicate slant range to the target.
two-way travel time of the radar pulse
The user controls the time required to move a PPI sweep. What effect does this have on increasing or decreasing the range
It varies
The PPI sweep is electronically rotated around the screen at ______.
the same rotation rate as the antenna
What is the primary automation system used throughout the FAA
STARS (Standard Terminal Automation Replacement System)
The ____ is an LCD workstation designed for high-light environments
Tower Display Workstation (TDW)
