[Kwajalein Telemetry Station]

Photo Kwaj Telemetry Ground Station (Telemetry Hill)

RTS telemetry ground stations

Single-channel concial-scan 1700-2400MHz with 2200-2400 autotrack capability

S-band omni at Illeginni

4 fixed S-band systems at Gagan

Gagan S-band: 18.5dB @ 2.25GHz, Ts=350K, G/T=-7.5dB, BW=15¡Æ, 2.2-2.4GHz

Gagan S-band: 15.0dB @ 2.25GHz, Ts=350K, G/T=-12dB, BW=30¡Æ, 2.2-2.4GHz

Roi 3-m L/S-band system: 32.9dB @ 2.25GHz, Ts = 175K, G/T = 11.0dB, 2.8¡Æ beamwidth, 1.7-2.4GHz

Roi 5-m L/S-band system: 36.4dB @ 2.25GHz, Ts = 175K, G/T = 16.0dB, BW=1.75¡Æ, 1.7-2.4GHz

Roi 7-m L/S-band system: 41.0dB @ 2.25GHz, Ts=350K, G/T=18.5dB, BW=1.3¡Æ

Kwajalein 3-m L/S-band system: 34dB @ 2.25GHz, Ts = 175K, G/T=11.0dB, 3dB beamwidth 3.0¡Æ, 1.7-2.4GHz

Kwajalein 5-m L/S-band system: 38.5dB @ 2.25GHz, Ts=175K, G/T=16dB, 1.8¡Æ beamwidth, 1.7-2.4GHz

Kwajalein 7-m L/S-band system: 41.0dB @ 2.25GHz, Ts=350K, G/T=18.5dB, 1.3¡Æ beamwidth, 1.7-2.4GHz

 

[Modulation]

PCM/FM

PCM/FM/FM

FM/FM

PM

BPSK

QPSK

FM

Standard IRIG

 

[Mobility]

Mobile: TTS(transportale telemetry system)

Stationary

 

[Equipments and Facilities]

Antenna control (room): dual-axis Kineto Tracking Mount

Communications: ground, satellite, ViaSat tracking antenna, SeaTel, Inmarsat

Data distribution

Data separation

Display

Fiber-optic link

General-purpose tests

Receiving

Recording

Shelters: electronic equipments, power, SatCom, constructed to ISO 1496-1

Specificic tests

Timing

Tracking: auto-tracking

 

[Types]

Telemetry station: 3-11m reflector antenna

Post impact TM system (PITS): disc-on-rod cone, dual-polarized antenna, receives wideband TM data signals (2.2-2.4GHz)

 

[IRIG]

IRIG format serial time codes: IRIG document 200-89

IRIG A: 10kHz carrier, 0.1ms resolution, 1000 pps BCD time of year, A002 time code (pulse width coded = level shift), A132 time code (sinewave AM)

IRIG B: 1kHz carrier, 1ms resolution, 100 pps, B002 time code, B122 time code

IRIG E: 1kHz carrier, 1ms resolution, 10pps, E002, E122

IRIG G: 1kH carrier, 0.01ms resol., 10kpps, G142

IRIG H: 1kHz, 1ms resol., 1pps, H002, H122

 

[Shelters]

Inside dimension: 8'W x 8'H x 30'L (39'L)

Paneling: 0.050 AL paneling over AL hatposts

Insulation: Wall and ceiling insulation

Undercarrigage: insulated and finished with 3M undercoating

Lighting: surface mount fluorescent, Vaporite incandescent fixtures

Transportation: flatbed trailer, train, container ship, aircraft

 

[White Sands Missile Range]

http://www.emitechnologies.com/images/photos/281601.jpg http://www.emitechnologies.com/images/photos/281602.jpg

http://www.emitechnologies.com/images/photos/281606.jpg http://www.emitechnologies.com/images/photos/281607.jpg

- ViaSat tracking antenna

http://www.emitechnologies.com/images/photos/281605.jpg

http://www.emitechnologies.com/images/photos/gpiv59.jpg http://www.emitechnologies.com/images/photos/gpiv61.jpg

- Scientific Atlanta 8' dish with E-scan telemetry system

http://www.emitechnologies.com/images/photos/8001.jpg http://www.emitechnologies.com/images/photos/8002.jpg

 

[Glossary]

TRS(telemetry receiving system)

 

[Technical Information]

- 6 fiberglass spars tranparent to the antenna frequency: TLM-18 60' reflector antenna

http://www.globalsecurity.org/space/library/report/1991/6555th/tracaz.jpg

- Single RHCP antenna: TLM-18

- Rotating lens for conical scan: TLM-18, metal disks inserted in a polyester environment

- Conical scan: 600rmp feed lens rotation ¡æ 10Hz error signal

     Received signal combined with reference signal ¡æ I/O signal ¡æ mag/phase compared with two reference signals in the demodulator ¡æ DC voltages for AZ/EL error (magnitude and polarity) ¡æ antenna positioner motor control

- Multicoupler: RF input = 1, RF output = 8

- Sensitivity of tracking signal: well below the sensitivity of data communication because the bandwidth can be greatly reduced. In TLM-18, 0.2uV at 50ohms = -120dBm

- Sun noise: increases the noise level significantly

- Tracking distance in LOS range:

 108MHz: 0.5W 0dBi Tx, 60' Rx antenna, 71000 mi

- TLM-18 antenna measured performance at 108MHz

G = 29.5dB (sun noise level compared with a standard gain horn)

BW = 5.2¡Æ

SLL < -20dB

 

[Antenna Control]

1. Damage protection features

- Automatic brakes: limit the antenna elevation movement angular range

- Dashpot: velocity limiter, operates if angular speed exceeds 1¡Æ/s

 

2. Antenna wobbling

- AM modulation of incoming signal 4-20Hz: resultant distortion of 10Hz antenna control signal ¡æ antenna is trying to hunt for target rather than smooth tracking

 

3. Effect of multipath

- Large scattering objects: launch pad, buildings

- At low angles: below 10¡Æ elevation

- Manual operator intervention: video cam's boresight aligned with that of the antenna, operator manually steers the antenna to the target direction

- Refraction, ducting, reflection, etc. have an effect of amplitude-modulating the carrier in a random fashion

 

[Feed Design]

1. TML-18: 216-245MHz, RHCP, 60' reflector, 29.5dB gain, 5.2¡Æ BW, SLL < -20dB, circular WG feed with rotating lens concial scan

tlm18pic003.jpg

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