29-10-2012, 10:48 AM
TRANSMITTER AND RECEIVER SYSTEMS
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Radio Frequency Standards for Telemetry
These standards provide the criteria to determine equipment and frequency use requirements and are intended to ensure efficient and interference-free use of the radio frequency spectrum. These standards also provide a common framework for sharing data and providing support for test operations between ranges. The radio frequency spectrum is a limited natural resource; therefore, efficient use of available spectrum is mandatory. In addition, susceptibility to interference must be minimized. Systems not conforming to these standards require justification upon application for frequency allocation, and the use of such systems is highly discouraged.
UHF Bands
The bands used for telemetry are described unofficially as the lower-L band from 1435 to 1535 MHz, the lower S-band from 2200 to 2290 MHz, and the upper S-band from 2310 to 2395 MHz (see Table 2-1). The 1755 to 1850 MHz band (unofficially called “upper L-band”) can also be used for telemetry at many test ranges although it is not listed in the NTIA Table of Allocations explicitly as a telemetry band. The mobile service is a primary service in the 1755 to 1850 MHz band and telemetry is a part of the mobile service. Since the 1755-1850 MHz band is not considered a standard telemetry band per this document, potential users must coordinate, in advance, with the individual range(s) and ensure use of this band can be supported at the subject range and that it will meet their technical requirements. While these band designations are common in telemetry parlance, they may have no specific meaning to anyone else. Telemetry assignments are made for testing2 manned and unmanned aircraft, for missiles, for space, land, and sea test vehicles, and for rocket sleds and systems carried on such sleds. Telemetry assignments are also made for testing major components of the systems shown above.
UHF Telemetry Transmitter Systems
Telemetry requirements for air, space, and ground systems are accommodated in the appropriate UHF bands 1435 to 1535, 2200 to 2300, and 2310 to 2390 MHz as described in paragraph 2.3.
Center Frequency Tolerance. Unless otherwise dictated by a particular application, the frequency tolerance for a telemetry transmitter shall be ±0.002 percent of the transmitter's assigned center frequency. Transmitter designs shall control transient frequency errors associated with startup and power interruptions. During the first second after turn-on, the transmitter output frequency shall be within the occupied bandwidth of the modulated signal at any time when the transmitter output power exceeds -25 dBm. Between 1 and 5 seconds after initial turn-on, the transmitter frequency shall remain within twice the specified limits for the assigned radio frequency. After 5 seconds, the standard frequency tolerance is applicable for any and all operations where the transmitter power output is -25 dBm or greater (or produces a field strength greater than 320 μV/meter at a distance of 30 meters from the transmitting antenna in any direction). Specific uses may dictate tolerances more stringent than those stated.
[attachment=37234]
Radio Frequency Standards for Telemetry
These standards provide the criteria to determine equipment and frequency use requirements and are intended to ensure efficient and interference-free use of the radio frequency spectrum. These standards also provide a common framework for sharing data and providing support for test operations between ranges. The radio frequency spectrum is a limited natural resource; therefore, efficient use of available spectrum is mandatory. In addition, susceptibility to interference must be minimized. Systems not conforming to these standards require justification upon application for frequency allocation, and the use of such systems is highly discouraged.
UHF Bands
The bands used for telemetry are described unofficially as the lower-L band from 1435 to 1535 MHz, the lower S-band from 2200 to 2290 MHz, and the upper S-band from 2310 to 2395 MHz (see Table 2-1). The 1755 to 1850 MHz band (unofficially called “upper L-band”) can also be used for telemetry at many test ranges although it is not listed in the NTIA Table of Allocations explicitly as a telemetry band. The mobile service is a primary service in the 1755 to 1850 MHz band and telemetry is a part of the mobile service. Since the 1755-1850 MHz band is not considered a standard telemetry band per this document, potential users must coordinate, in advance, with the individual range(s) and ensure use of this band can be supported at the subject range and that it will meet their technical requirements. While these band designations are common in telemetry parlance, they may have no specific meaning to anyone else. Telemetry assignments are made for testing2 manned and unmanned aircraft, for missiles, for space, land, and sea test vehicles, and for rocket sleds and systems carried on such sleds. Telemetry assignments are also made for testing major components of the systems shown above.
UHF Telemetry Transmitter Systems
Telemetry requirements for air, space, and ground systems are accommodated in the appropriate UHF bands 1435 to 1535, 2200 to 2300, and 2310 to 2390 MHz as described in paragraph 2.3.
Center Frequency Tolerance. Unless otherwise dictated by a particular application, the frequency tolerance for a telemetry transmitter shall be ±0.002 percent of the transmitter's assigned center frequency. Transmitter designs shall control transient frequency errors associated with startup and power interruptions. During the first second after turn-on, the transmitter output frequency shall be within the occupied bandwidth of the modulated signal at any time when the transmitter output power exceeds -25 dBm. Between 1 and 5 seconds after initial turn-on, the transmitter frequency shall remain within twice the specified limits for the assigned radio frequency. After 5 seconds, the standard frequency tolerance is applicable for any and all operations where the transmitter power output is -25 dBm or greater (or produces a field strength greater than 320 μV/meter at a distance of 30 meters from the transmitting antenna in any direction). Specific uses may dictate tolerances more stringent than those stated.