The TWT operates by optical pulses received from the DMT's internal Pulse Decker Unit and TWT Cathode/Anode voltage inputs. Dual Mode Transmitter (DMT) - A 24,000 volt radar transmitter, containing a TWT, which generates the amplified RF to be sent to the radar Antenna for system emission.The MLPRF also is responsible for the receiving of the radar return, generating the RF injection noise (for RF discrimination), and the processed RF within the MLPRF is then later sent to the PSP for video processing and threat/target matching against the radar threat tables within the PSP, prior to flightcrew system display. The MLPRF will generate a small amount of RF Drive, which is sent to the Dual Mode Transmitter (DMT), where it is amplified and a small RF sample is sent to the MLPRF for comparison checksum (more like a check and balance system). Frequency generation is dependent on the random frequency selection from the radar tables within the PSP upon system start-up. Modular Low Powered Radio Frequency (MLPRF) - The frequency generator for the radar system.The PSP also contains all the controls circuitry for radar A/A and A/G operational scan patterns and SAR/ISAR operation. The PSP is directed by the system operational flight program (OFP), which is controlled and modified for new threats or addition radar system requirements. The PSP is controlled through the F-16 Heads Down Display Set (HDDS) or what is commonly called the Multi-Function Displays (MFDs). Programmable Signal Processor (PSP) - The core radar component which is responsible for signal processing, frequency selection, signal digitization for B-Scope display.Azimuth angular coverage: ☑0 degrees / ± 30 degrees / ± 60 degrees.Frequency: Starting Envelope frequency around 9.86 GHz.The APG-68(V)9 has equipped several variants, including the Egyptian Air Force, Israeli Air Force, Chilean Air Force, Republic of Singapore Air Force, Turkish Air Force, Royal Moroccan Air Force, Greek Air Force, Pakistan Air Force, Polish Air Force, Royal Thai Air Force, and Indonesian Air Force. Besides the increase in scan range compared to the previous version, it has a Synthetic aperture radar (SAR) capability. The AN/APG-68(V)9 radar is the latest development. The AN/APG-68(V)9 radar system consists of the following line-replaceable units: Modular Low-power radio frequency (MLPRF).The AN/APG-68(V)8 and earlier radar system consists of the following line-replaceable units: The AN/APG-68 radar is a long range (up to 296 km) Pulse-doppler radar designed by Westinghouse (now Northrop Grumman) to replace AN/APG-66 radar in the F-16 Fighting Falcon. Since hail can cause the rainfall estimates to be higher than what is actually occurring, steps are taken to prevent these high dBZ values from being converted to rainfall.Starting Envelope frequency around 9.86 GHz Hail is a good reflector of energy and will return very high dBZ values. These values are estimates of the rainfall per hour, updated each volume scan, with rainfall accumulated over time. Depending on the type of weather occurring and the area of the U.S., forecasters use a set of rainrates which are associated to the dBZ values. The higher the dBZ, the stronger the rainrate. Typically, light rain is occurring when the dBZ value reaches 20. The scale of dBZ values is also related to the intensity of rainfall. The value of the dBZ depends upon the mode the radar is in at the time the image was created. Notice the color on each scale remains the same in both operational modes, only the values change. The other scale (near left) represents dBZ values when the radar is in precipitation mode (dBZ values from 5 to 75). One scale (far left) represents dBZ values when the radar is in clear air mode (dBZ values from -28 to +28). Each reflectivity image you see includes one of two color scales. The dBZ values increase as the strength of the signal returned to the radar increases. So, a more convenient number for calculations and comparison, a decibel (or logarithmic) scale (dBZ), is used. Reflectivity (designated by the letter Z) covers a wide range of signals (from very weak to very strong). "Reflectivity" is the amount of transmitted power returned to the radar receiver. The colors are the different echo intensities (reflectivity) measured in dBZ (decibels of Z) during each elevation scan.
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