Page 336 - Radar Technology Encyclopedia

radar, airport surveillance (ASR) radar, air-route-surveillance (ARSR) 326

Figure R8 ASR-9 radar antenna (from Skolnik, 1990,
Figure R9 ASR-10SS radar antenna (Raytheon Company
Fig. 6.14, p. 6.19).
photo).
when both are operating and graceful degradation of perfor-
mance in the event of failure in one chain. The main features of the ASR-10SS are
The latest generation of ASRs is represented by the Ray- (1) Dual-beam antenna with sharp lower edge cutoff.
theon solid-state ASR-10SS (Fig. R9). The all-solid-state (2) Selectable circular or linear polarization.
design simplifies radar servicing, gives high reliability and (3) Frequency diversity, frequency agility, and PRF stag-
maintainability, and permits unattended operation at remote ger.
sites. It also provides operational and cost flexibility, as the (4) Dedicated weather and target channels.
number of amplifier modules used in the transmitter can eas- (5) Highly reliable, multichannel, fully solid-state trans-
ily be changed. mitter with fail-soft operation.
(6) Dual receiver-processor channels with automatic
Table R2 reconfiguration in event of failure.
Major Parameters of ASR-9 and ASR-10SS
(7) Digital signal processing with I- and Q-channels and
doppler MTD. DKB, SAL
Parameter Units ASR-9 ASR-10SS
Ref.: IEEE (1993), p. 23; Skolnik (1988), pp. 89–94
Frequency band S S
An air-route-surveillance radar (ARSR) is “a long-range
1)
Peak power kW 1,300 15 , 30 2) (for example, 200 nautical miles) surveillance radar used to
control aircraft on airways beyond the coverage of airport
Pulse width m s 1.0 1.0, 100
surveillance radar (ASR).” A typical ARSR has a scan period
Pulse repetition Hz 1,200 825 3) of 10 to 12s, operates at L-band, and provides two-coordinate
frequency data (range and azimuth). A secondary surveillance radar
(SSR) antenna is usually mounted on the rotating radar anten-
1)
2)
Average power kW 1.6 1.3 , 2.6
na. Important performance characteristics of an ARSR are
Antenna gain dB 33.5 34.5 long detection range, ability to reject both land and weather
clutter, ability to process and output data on many tens of tar-
Azimuth beamwidth deg 1.3° 1.4°
gets, and reliability.
2
2
Elevation beamwidth deg 4.8° csc to 5° csc to The Alenia ATCR-22 is typical of ARSRs developed
30° 40° during the 1970s, and its major parameters are shown in Table
Scan rate rpm 12.5 15 3) R3. The newest U.S. ARSR is the ARSR-4 (Fig. R10), a joint
development for the FAA and the U.S. Air Force, which pro-
Receiver noise factor dB 4.5 3.3
vides long-range two-dimensional data for air traffic control
Clutter rejection MTD, STC MTD, pulse and also three-dimensional data for the continental air
methods compression,
defense network. The latest generation of ARSR is repre-
STC
sented by the Raytheon ASR-23SS (Fig. R11), which is a
1)
Detection range km 100 125 , 150 2) fully solid-state radar, whose parameters are also shown in
2
(1 m , 80%) Table R3. The basic features of the ASR-23SS are identical to
2)
1)
Notes: 8-module transmitter; 16-module transmitter, those of ASR10-SS (see airport surveillance radar). DKB
3) average for 100-km instrumented range Ref.: IEEE (1993), p. 23; Skolnik (1988), pp. 70–88.