Volume 3 URE Flashcards
1
Q
In the tropospheric scatter mode, the high power amplifier amplifies the radio frequency to ________.
A
1 kilowatt
2
Q
Which type of diversity requires two antennas, two receivers, and two transmitters?
A
Polarization
3
Q
The MD-1026 digital data modem can interface up to four groups of which type of signal?
A
Conditioned diphase
4
Q
The trunk group multiplexer TD-1236 can multiplex up to _________.
A
four groups of the 512 kbps data rate families or 576 kbps data rate families
5
Q
Digital Voice orderwire traffic that originates at the AN/TRC-170’s voice orderwire control unit is encrypted by the ________.
A
KY-58
6
Q
Which jack field in the AN/TRC-170’s baseband patch panel provides timing and data connections?
A
Upper
7
Q
The tropospheric scatter modem processes mission traffic at data rates of 128 through 4096 kbps, within which data rate family?
A
512 kbps
8
Q
Which unit in the AN/TRC-170 terminal contains the rubidium standard?
A
Tropospheric scatter modem
9
Q
The quick reaction antenna for the V3 AN/TRC-170 terminal uses how many linearly dual-polarized antennas?
A
Two 6-foot diameter
10
Q
The Tropo/Satellite Support Radio frequency coverage extends from ________.
A
14.4-15.25 GHz
11
Q
Which maximum distance in miles can a Tropo/Satellite Support Radio operate with the 2-foot antenna?
A
24
12
Q
What is the maximum distance in feet to which the Tropo/Satellite Support Radio’s radio frequency and baseband assemblies can be separated and still operate?
A
150
13
Q
In the Tropo/Satellite Support Radio’s baseband assembly, a 1 Vpk-pk input signal results in how much frequency deviation in the transmitter?
A
+/- 4 MHz
14
Q
Which frequency is the intermediate frequency of the Tropo/Satellite Support Radio?
A
70 MHz with a 20 MHz bandpass
15
Q
What is the inclination angle of a polar orbit?
A
90 degrees
16
Q
What is the procedure of keeping a satellite in a desired position, in orbit and within acceptable limits, called?
A
Station keeping
17
Q
Which satellite reflects signals transmitted toward it?
A
Passive
18
Q
An advantage of passive satellites is that they _______.
A
operate over a relatively wider frequency range
19
Q
What is the time delay in seconds of a real-time satellite?
A
0.6
20
Q
Which satellite access technique was the first multiple access method developed?
A
Frequency division multiple access (FDMA)
21
Q
Which satellite access technique is being used when all channels are pooled and used by any station, according to its instantaneous traffic load?
A
Demand assigned multiple access (DAMA)
22
Q
To calculate look angles (e.g. antenna azimuth and elevation) from the ground terminal to the satellite, you need to know the terminal’s longitude and latitude, as well as the satellite’s latitude, longitude, and _________.
A
height
23
Q
When computing satellite look angles, the ground distance on the earth’s surface is expressed in ________.
A
degrees
24
Q
What does one degree of arc on the Earth’s surface equal?
A
69 statute miles
25
Solar time is based on _______.
the apparent motion of the sun in the sky
26
An atomic time scale could be based on the frequency of what type of oscillator?
Cesium
27
What kind of clock system is coordinated universal time (UTC) based?
24-hour
28
A number of organizations can maintain accurate time-of-day clocks by referencing a standard time interval of one __________.
second
29
The agency responsible for coordinated universal time (UTC) is the _________.
International Bureau of Weights and Measures (BIPM)
30
Uploading satellite control data, tracking missiles, and predicting satellite tracking coordinates are examples of missions where all parties involved must have ________.
synchronized timing
31
When any frequency source regardless of its accuracy or stability is used as the sole calibration reference for other frequency sources, what kind of standard is it?
Primary
32
What two factors cause a quartz oscillator's resonant frequency to drift?
Temperature and aging
33
The operation of the atomic clock is based on the principle that __________.
atoms release energy at a particular resonant frequency
34
To send information over telephone lines, the modulator in a voice modem converts the _________.
digital data into an audio signal
35
What is multiplexing?
Combining multiple signals for transmission over a single transmission path
36
Which division technique of multiplexing samples each low speed channel in sequence to interleave bits or characters, and then transmit them at high speed?
Time
37
What specifically does wavelength division multiplexing assign each incoming optical signal?
Frequency of light
38
What comprises a telemetry data stream?
Mission data, mission satellite health, and status data
39
Stability is important to a satellite in the space environment. What does stability allow that makes it so important?
The payload to operate accurately and the satellite bus to receive commands and upload data reliably
40
On a satellite, position and orientation control is especially critical for which type of antenna?
Highly directional
41
The purpose of satellite antenna pointing data is to _________.
direct the servo positioning equipment to drive motors that position the antenna to specific acquisition angles
42
This type of command, sent to the satellite by the space systems mission control complex, contains embedded timing that specifies the time the satellite will execute the command.
Stored program
43
What is the purpose of the space system user segment?
Receive, process, use, or distribute mission data as required by a program's tasking
44
The two major subdivisions if the Defense Meteorological Satellite Program user segment are _______.
Air Force Weather Agency and the Fleet Numerical Meteorology Oceanography Center and tactical terminals
45
Which early warning center receives Defense Support Program warning data from the 460th Space Wing units?
North American Aerospace Defense Command
46
What system supports the National Command Authority and provides all service(Army, Navy, AF) communication for interoperable command, control, and communications (C3) at all levels of conflict?
Military Strategic and Tactical Relay
47
Telemetry refers to _________.
the data transmitted by the satellite concerning on-board status and is separate from the communications components
48
Automatic tracking systems are superior to programmed tracking systems because they ________.
track only signals received from the satellite
49
What signal originating from the satellite do we use to acquire and track the satellite?
Beacon
50
The intermediate frequencies/levels used by Defense Satellite Communications Subsystem (DSCS) earth terminals are 70 MHz at ______________.
- 10 dBm and 700 MHz at -13 dBm
51
The super-high frequency (SHF) downlink frequency range of the Defense Satellite Communications Subsystem (DSCS) is ________.
7.25 GHz to 7.75 GHz
52
The AN/GSC-52 earth terminal uses a _______.
Cassegranian fed 38-foot antenna
53
In the AN/GSC-52 earth terminal's tracking system, the azimuth-plus (+AZ), azimuth-minus (-AZ), elevation-plus (+EL), and elevation-minus (-EL) signals are fed to the _______.
comparator
54
What information is used for satellite tracking on the AN/GSC-52 earth terminal operating in the memory track mode?
Recorded data
55
Which of the following is not used to control the AN/GSC-52 earth terminal?
- Remote terminal processor (RTP)
- External control element
- Internal control element
- Terminal processor (TP)
Internal control element
56
Which feedhorns are located in the AN/GSC-52 earth terminal feed assembly?
Four tracking feedhorns and one communication feedhorn
57
How are the high power amplifiers normally configured in the AN/GSC-52 earth terminal?
Three operating online with one hot standby
58
What happens in the event of a downconverter failure in the AN/GSC-52 earth terminal?
The downconverter switch assembly (under terminal server A control) automatically places a spare online
59
In the AN/GSC-52, the upconverter or downconverter normally dedicated to automatic switchover is in rack position number _________.
8
60
Which Defense Meteorological Satellite Program (DMSP) elements receive only real-time satellite imagery when the satellite is in view?
Tactical
61
The MARK IVB antennas can be located up to how many feet away from the processing area?
1500
62
The MARK IVB product control subsystem uses which type of operating system?
UNIX
63
The primary interface between the operator/maintainer and the MARK IVB system is the _________.
maintainer workstation
64
Which mission is the most important of the Defense Support Program (DSP)?
North American warning
65
Which agency is responsible for Defense Support Program (DSP) operational control?
Space Air Force (SPACEAF) (14AF)
66
What does the transmit/receive set do in the satellite readout station?
It receives and processes downlink satellite signals, and generates and transmits uplink satellite commanding and ranging signals
67
What is the number of global positioning system (GPS) orbital planes?
6
68
What provides command and control (C2) operations for the space segment?
Master control station
69
What is the purpose of the global positioning system (GPS) ground antenna?
To serve as the interface between the master control station and the satellites
70
Which global positioning system (GPS) operation control segment component is remotely operated and also transmits and receives telemetry to and from the satellites?
Ground antenna
71
What is the minimum number of global positioning system (GPS) satellites that must be tracked in order to have accurate three-dimensional navigation?
Four
72
For global positioning system (GPS) receivers, how much of a difference in target coordinates is there if the Datum mismatches?
750 meters
73
What is the primary advantage of using an extremely high frequency communications link for critical command and control (C2) data?
EHF communications are less affected by scintillation
74
Which Military Strategic and Tactical Relay (MILSTAR) capability is very different from previous military satellite communications (MILSATCOM) and commercial satellite communications systems?
Crosslinking
75
Which element of the military strategic and tactical relay (MILSTAR) mission allocates communication resources?
Planning
76
The secure mobile anti-jam reliable tactical terminal (SMART-T) provides user data rates through what type of cable?
T-1 (1.544 Mbps)
77
The military strategic and tactical relay (MILSTAR) waveform derived its anti-jam (AJ) capabilities by using a _____________.
large bandwidth
78
Encoding/decoding of a digital signal _______________.
enhances the link bit error rate
79
Which type of extremely high frequency (EHF) antenna is used on the military strategic and tactical relay (MILSTAR) EHF and ultra high frequency (UHF) airborne command post terminals?
Cassegrain 26-inch dish
80
What agency plans and executes satellite tracking and ephemeris data generation?
Commander, United States Strategic Command (USSTRATCOM)
81
Which agency provides the regional satellite communications support center with resource allocation parameters?
Defense Information Systems Agency (DISA)
82
Who is responsible for satellite launch support, orbit maintenance, and relocation?
Air Force Space Command (AFSPC)
83
Modifications on the Defense Satellite Communications System phase III (DSCS III) satellite include ___________.
single-channel transponder (SCT) downlink
84
Which satellite system provides Global Broadcast Services (GBS)?
Ultrahigh frequency (UHF) Follow-on
85
Which of the following is not a service provided by the commercial satellite communications branch (CSB)?
* Help obtain host nation approvals
* Recommend and/or obtain ground terminals
* Act as the day-to-day mobile satellite services (MSS) system manager
* Evaluate customer requests to see if commercial service is the best option
Act as the day-to-day mobile satellite services (MSS) system manager
86
Which commercial satellite communication system can offer true pole-to-pole global coverage?
Iridium
87
Which service provider is a new satellite communications company specifically dedicated to provide commercial X-band services exclusively to US and allied governments?
XTAR
88
One of the functions of the telecommunication certification office is to ____________.
ensure the user agency is prepared to pay for the service
89
Telecommunications service orders are issued by the ___________.
Defense Information Systems Agency (DISA)
90
Command communications service designators (CCSD) are divided into two classes, which are ____________.
permanent and temporary
91
All approved satellite communication network requirements will be assigned a number and reside in the ___________.
SATCOM Database (SDB)
92
Telecommunications circuit restoration is normally done by _____________.
rerouting to spare channels
93
With which agency does the regional satellite communications support center (RSSC) coordinate for additional satellite resources if the planned deployment configuration can not be supported by the satellite payload configuration?
Defense Information Systems Agency (DISA)
94
Which office resolves conflicts regarding Defense Satellite Communications System (DSCS) ground mobile force (GMF) satellite resources that can not be settled by the Defense Information Systems Agency (DISA) and the regional satellite communication support center?
Joint Staff
95
What agency initiates satellite access authorizations for missions using nonstandard tactical terminals?
Defense Information Systems Agency (DISA)
96
An effective global information grid (GIG) quality control program consists of all of the following except __________.
* out-of-service performance monitoring
* in-service performance monitoring
* out-of-service testing
* trend analysis
out-of-service performance monitoring
97
Which term is defined as those measures taken to ensure the continued use of the frequency spectrum by the Department of Defense (DoD) and friendly forces?
Counter-counter measures (CCM)
98
What is the name of the companding scale used in US telephone networks, and standardized for analog-to-digital conversion?
Mμ-Law
99
Because they use differing conversion scales, which process must take place in order to transmit voice/data between telephone networks in the US and European countries?
Transcoding
100
What is the logical connection between two nodes that consists of one or more trunks?
Link
