CIWS Flashcards
(44 cards)
What is the purpose of CIWS?
To provide HMCS CHARLOTTETOWN with a point-defence, damage-limiting, hard-kill capability against air and surface targets.
What is the signal generator?
The signal generator consists of six oscillating crystals each capable of producing a different frequency. The signal generator receives information from the weapons control group (WCG) via the target detection processor (TDP) and sends the RF signal to the transmitter for amplification. It is located in the Barbette.
What is the klystron?
The klystron amplifies the RF signal produced by the signal generator. While it has a peak power of 25kW, the average power is only around 4kW. This signal is then sent to the transmitter.
What is the transmitter?
Both the track and search radars share a common transmitter (located in the barbette). A waveguide switch in the receiver is used to select whether the transmitter is currently feeding the track or search radar. There is also a dummy load that the transmitter can radiate into.
What is the search radar?
The search radar has four arrays corresponding to its four beams and is located on the top of the mount. The search radar is a J-Band radar capable of operating in two different modes: primary (low-PRF MTI) and secondary (high-PRF). The search antenna is on a gimballed platform and can move +/- 30 deg in pitch and roll relative to the gun mount and the antenna can move 360 deg relative to the mount in azimuth. The search antenna rotates at a fixed rate of 90 rpm.
Note: PRF is pulse repetition frequency. High = unambiguous Doppler, low = unambiguous range
What is the track radar?
The track radar consists of four feed horns in order to perform monopulse tracking. It is used to track the target as well as the fall-off shot for continuous aim correction (CAC). The track antenna is on a gimballed platform and can move +/- 15 deg in azimuth relative to the mount and +7.5 and -10 deg in elevation relative to the mount. It is fixed to the mount in roll.
What is the receiver?
The receiver is used for both the search and track radars. It filters, amplifies and converts the return signal into an 80 MHz signal. It also contains the two delta channels for traverse and elevation (monopulse comparator). It is located in the barbette. On transmit, RF energy is routed from the klystron to the receiver to the search/track antennas using a waveguide switch.
What is the Target Detection Processor (TDP)?
The TDP filters and processes the data from the search radar and looks for moving targets. Any valid targets that are detected are plotted on the search mapper according to their range, bearing and antenna beam data. The TDP also searches for sources of interference such as jamming. Target and jammer tracks are sent to the weapons control group (WCG). The TDP is also responsible for routing commands from the WCG to the signal generator. It is located in the ELX enclosure.
What is the Vertical Reference Unit (VRU)?
The VRU uses three accelerometers and two gyroscopes to calculate roll, pitch, and yaw about the gun’s axis, as well as gun linear acceleration in three dimensions. This data is provided to the servos for stabilization. It is located in the mount.
What is the Radar Servos?
The Radar servos can be split up into two seperate servos: the search radar servo and the track radar servo.
The Search Radar Servo provides search antenna rotation, a stabilized platform for the rotating search antenna, the bearing of the rotating search antenna beam, and Gun mount heading for use in mount slewing during radar handover.
The track radar servo provides limited track antenna angle search during acquisition mode, maintains the radar boresight on the target during track mode and provides antenna position information for use in gun aiming.
What is the Weapons Control Group (WCG)?
The WCG is responsible for CIWS mode control, radiation control, search processing, handover, acquisition, fire control solution, operability testing, and console displays. When the TDP has identified a target, and the WCG has determined that it is a threat and in the right position, the WCG will send a recommended fire signal to the consoles. The WCG is located within the ELX enclosure.
What is the Gun Control Unit (GCU)?
The GCU places the gun in either safe or armed condition, monitors and displays gun subsystem status, and interrupts gun firing if the gun is pointed in a firing cutout.
What is the Pneumatic Gun Drive System (PnGD)?
The PnGD provides the motive power to actuate the gun and the ammunition drum. It contains its own compressor and an air bottle that stores air at up to 3150 psi. It takes air from the atmosphere and cleans, dries, compresses and stores it. The air bottle is good for two full firings if the compressor fails.
Describe the gun itself on the CIWS
The gun itself is an M61 Vulcan 20 mm which consists of 6 barrels, each with its own breach assembly. It provides a high rate of fire of 4500 rounds/min in AAW mode and 3000 rounds/min in surface mode. In AAW mode it fires continuously, whereas in surface mode it fires in either a 1.2 s or 2 s burst.
What is the gun servo?
The gun servo is a one-piece casting that provides structural support to the gun subsystem and radar servos as well as houses the servo drive components that provides elevation control of the gun. The mount servos use two DC motors per axis to drive the gun in elevation and train. The high-performance drive systems can track accurately at rates up to 100 deg/sec in train and 86 deg/sec in elevation.
What is the electro-optical subsystem?
This subsystem provides infrared detection and tracking of surface and low-flying air targets.
What is the Phalanx Thermal Imager (PTI)?
The PTI is a long-wave infrared camera that detects infrared target signals and sends them to the acquisition video tracker (AVT). It is located on the electro-optical stabilization system (EOSS) pedestal.
What is the Electro-Optical Stabilization System (EOSS)?
The EOSS is a two-axis pedestal mounted on the side of the CIWS radome. It contains its own motors for stabilization.
What is the Acquisition Video Tracker (AVT)?
The AVT receives video from the PTI, processes it, and tracks targets. It sends EO subsystem status and track info to the WCG. It can track targets based on the highest contrast pixels or a unique feature of a target. If the target disappears, the system will go into a coast state and attempt reacquisition
What is the Remote Control Station (RCS)?
The RCS is a human-machine-interface (HMI) that is used by the operators in the ops room to remotely control CIWS. The RCS can control the system in any of the CIWS operational modes, display system status, engagement status, indications, and data readouts. The RCS cannot perform maintenance functions.
What is the Local Control Station (LCS)?
The LCS is the only location from which engagement data can be entered into the WCG computer and it is located in FCER 3. No engage sectors, first hit range, and min and max fire rates can be inputted. The LCS is capable of everything the RCS is with the addition of transmission of ship heading reference signals and maintenance functions. If the RCS is inoperable, the LCS can take over control of CIWS. The LCS can act as a maintenance panel through a windows-based system known as PASS.
What is PASS?
PASS is parameter analysis and system storage. It is essentially a computer that the maintainers use to run tests on the system. It allows the use of operability tests and maintenance operations from the LCS.
What is the Test Point Selector Unit (TPSU)?
The TPSU is a unit that allows maintainers to run various BITs on the system known as SOTs and PSOTs. It is an emulator ran by the PASS computer and allows the operator to access various test interface modules (TIMs) located throughout the system.
