Section Ill - TECHNlCAL PRlNCIPLES OF OPERATION
PRINCIPLES OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-9. PRINCIPLES OF OPERATION.
1-9-1. System Fuctional Description (Figure 1-2). The AN/TMQ-38 Meteorological Measuring Set (MMS) is an
upper air meteorological data collection, processing, and dissemination system that provides data to field artillery,
target acquisition and air weather services to improve their mission capability. The AN/TMQ-38 Meteorological
Measuring Set works in conjunction with radiosondes, carried aloft by a balloon, to provide pressure, relative
humidity, temperature, wind speed and direction measurements to an altitude of 30 km above the earth's surface.
The MMS automatically tracks the radiosonde using Navigational Aids (NAVAIDS) or Radio Direction Finding
For NAVAID operation, the system utilizes signals from VLF/OMEGA or LORAN C radiosondes with a carrier
frequency of 403 MHz. Signals are received by the Antenna Set and routed through the Antenna Switch to
provide an input to the UHF Receiver within the MARWIN Processor. The Antenna Set consists of a whip
antenna for reception of Local NAVAID signals (VLF/OMEGA and LORAN C), a dipole UHF Omnidirectional
Antenna and a Directional Antenna for reception of 403 MHz radiosonde signals, and an Antenna Switch. The
UHF Omnidirectional Antenna is used for a range of up to 80 km. The UHF Directional Antenna is used to
receive radiosonde signals for a range of up to 160 km. The MARWIN Processor provides data processing of the
radiosonde signals which contain relayed NAVAID signals combined with PTU (air pressure, temperature, and
humidity) signals, converts the data into proper meteorological message format, and transmits the messages via
RS-232C communication links to the DCT and printer. The DCT digitally interfaces with the Field Artillery Tactical
Data System (FATDS), and is compatible with COMSEC units such as the KY-57. The printer utilizes ink jet
technology to make hard copy printouts of data and messages.
In the RDF mode, the MMS operates in the same manner except that the RDF Unit receives radiosonde signals
with a carrier frequency of 1680 MHz and automatically tracks the RF signal. PTU data received from the
radiosonde is demodulated by the RDF Unit and sent to the MARWIN Processor. The RDF Unit measures the
azimuth and elevation angles of the antenna while it is tracking the radiosonde and transfers this angle
positioning data to the MARWIN Processor via an RS-422 communication link. The Control Display Unit (CDU)
provides operator control of RDF Antenna. Azimuth, elevation, relative signal strength, and frequency data are
displayed by the CDU during flight.
1-9-2. MARWlN Processor, A1 (Figure 1-3). The MARWIN Processor is composed of a number of
microprocessor-based units communicating with each other via RS-232C serial lines. The major components of
the MARWIN Processor include the UHF Receiver, Receiver Processor, PTU Processor, VLF Processor,
LORAN-C Processor, Filters, Main Processor (Computer Subsystem), and Console Processor. Figure 1-3
illustrates the functional components of the MARWIN Processor and their interconnections. The Console
Processor controls the operator interface, Paper Tape Reader, indicator functions, and switches the MARWIN
Processor between normal operation and standby states. The operator interface includes the display and
membrane keyboard which is used to enter operator commands and data. The Main Processor manages real
time operation of the modules and performs higher level data processing. Application programs are permanently
stored in the Main Processor.
The MARWIN Processor operates in either NAVAID or RDF mode to receive and process positioning and PTU
data. In the NAVAID mode, the UHF Receiver receives radiosonde signals in the 400-406 Mhz range which
contain relayed NAVAID signals combined with PTU signals. These signals are filtered, processed by the