ISR
The Millstone Hill Incoherent Scatter Radar system is a high power large aperature radar that is used to observe the near space environment. The primary measurement technique used by the system is incoherent scatter from ionospheric plasma. This technique allows the density, temperature, velocity, and composition of the near space environment (ionosphere) to be determined with great accuracy. The system can also observe scatter from ionospheric turbulence, meteors, and satellites.
The radar is capable of making observations over a range from 90 to 1000 km in altitude. Geographic coverage is from just short of the arctic circle to the north, past Florida to the south, to the central atlantic ocean to the east, and out to Iowa in the west.
The radar system uses a high power transmitter in combination with a large antenna and highly sensitive radio receivers. A fixed vertically pointing antenna (Zenith) and a fully steerable antenna (MISA) are available for making ionospheric measurements. The fixed antenna is often used while moving the steerable one.
By making measurements in multiple directions the radar system can be used to determine the flows and electric fields which are present in the ionosphere.
| Radar System Parameters
| |||
| Location | |||
| Geodetic Latitude | 42.61950 ° | ||
| Geodetic Longitude | 288.50827 ° | ||
| Geodetic Altitude | 0.14600 km | ||
| Invariant Latitude (Lambda) | 53.40967 ° | ||
| Zenith Antenna | |||
| Type | zenith pointing fixed parabola | ||
| Diameter | 68 meters | ||
| Gain | 45.5 dBi | ||
| 3dB Beam Width | 0.6 ° | ||
| MISA Antenna | |||
| Type | fully steerable parabola | ||
| Diameter | 46 meters | ||
| Gain | 42.5 dBi | ||
| 3dB Beam Width | 1.2 ° | ||
| Max Azimuth Rate | 1.2 °/sec | ||
| Max Elevation Rate | 0.6 °/sec | ||
| Transmitter | |||
| Type | Dual Litton 5773 Klystron | ||
| Quantity | Two Independent Cabinets | ||
| Frequency | 440.0 to 440.4 MHz | ||
| Peak Power | 2.5 MW per TX unit | ||
| Avg Power | 150 KW | ||
| Duty Cycle | 6% | ||
| Pulse Widths | 1 usec to 2 msec | ||
| PRF Range | 0 to 15 kHz, 100 Hz typical | ||
| Modulation | Pulse, Binary Phase, Chirp | ||
| Bandwidth | 1 MHz maximum | ||
| Receivers | |||
| System Temperature | 120K typical | ||
| Total Noise Temperature | 150K typical | ||
| Data System Type | MIDAS-W Software Radar | ||
| DAQ | Echotek GC314-FS Digital RX | ||
| Bandwidth | 36 to 52 MHz Digitized | ||
| Channels | 12 max | ||
| Channel Bandwidth | 12@2.5 MHz, 6@5MHz, 3@10 MHz, 1@40 MHz | ||
| Time Base | GPS Locked to UTC | ||
| Frequency Stability | 2 parts in 10E11 | ||
| Data Transport | Gigabit Switched Ethernet | ||
| Processing | 32+ Gflops General Purpose CPU | ||
| Storage | 25+ TB RAID5 | ||
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