Jump to content

Galaxy 25

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Oschaper (talk | contribs) at 03:35, 7 May 2007. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

History

Galaxy 25 (G-25) launched in 1997, formerly known as Intelsat Americas 5 (IA-5) until february 15, 2007 when it was renamed as result of the merger between owner Intelsat and PanAmSat or Telstar 5) is a medium-powered communications satellite in the Clarke orbit at 97.0 degrees west, above a point in the Pacific Ocean several hundred miles west of the Galapagos Islands. It was manufactured by Space Systems/Loral, part of its FS-1300 line, and is currently owned and operated by PanAmSat. The satellite's main C-band transponder cluster covers the United States, southern Canada, and Mexico; its main Ku-Band transponder cluster covers the U.S., Mexico, and the northern Caribbean Sea. An additional C-band and a Ku-Band transponder pair targets the Hawaiian Islands.

Galaxy 25 has a projected life of 12 years, is scheduled to be replaced in late 2007 by Galaxy 19 (formerly IA-9).[1] Galaxy 25 transmits both free-to-air (FTA) direct-to-home (DTH) broadcasting and encrypted subscription channels / services.


Technical Details

Key Parameters
Total Transponders C-Band: 24x36 MHz
Ku-Band: 4x54 MHz, 24x27 MHz
Polarization C-Band: Linear - Horizontal or Vertical
Ku-Band: Linear - Horizontal or Vertical
e.i.r.p. (C-Band)
  • CONUS: 38.8 dBW
  • Alaska: 33.7 dBW
  • Caribbean: 34.3 dBW
  • Hawaii: 33.8 dBW
  • Mexico: 33.8 dBW
  • Puerto Rico / U.S. Virgin Islands: 34.0 dBW
  • Southern Canada: 37.0 dBW
e.i.r.p. (Ku-Band)
  • CONUS: 48.3 dBW
  • Alaska: 40.9 dBW
  • Caribbean: 43.4 dBW
  • Hawaii: 46.4 dBW
  • Mexico: 43.6 dBW
  • Puerto Rico / U.S. Virgin Islands: 44.9 dBW
  • Southern Canada: 44.3 dBW
Uplink Frequency C-Band: 5925 to 6425 MHz
Ku-Band: 14.00 to 14.50 GHz
Downlink Frequency C-Band 3700 to 4200 MHz
Ku-Band: 11.7 to 12.2 GHz
G/T (C-Band)
  • CONUS: -0.7 dB/K
  • Alaska: -8.2 dB/K
  • Caribbean: -4.7 dB/K
  • Hawaii: -5.2 dB/K
  • Mexico: -5.4 dB/K
  • Puerto Rico / U.S. Virgin Islands: -4.6 dB/K
  • Southern Canada: -2.3 dB/K
G/T (Ku-Band)
  • CONUS: +0.7 dB/K
  • Alaska: -3.3 dB/K
  • Caribbean: -3.2 dB/K
  • Hawaii: +0.6 dB/K
  • Mexico: -4.2 dB/K
  • Puerto Rico / U.S. Virgin Islands: +0.7 dB/K
  • Southern Canada: -1.6 dB/K
SFD Range (Beam Edge) C-Band: -92.0 to -71.0 dBW/m2
Ku-Band: -96.0 to -75.0 dBW/m2

Glossary

Beam edge EIRP, G/T or flux density contour corresponding to the minimum performance over a coverage area.
Beam peak A single point within a coverage area with highest performance (i.e., EIRP, flux density or G/T)
dBW A decibel referenced to one watt. Expresses units of decibels above 1 W. X (dBW) = 10 log 10 (X / 1W)
Downlink A transmission link carrying information from a satellite or spacecraft to earth. Typically down links carry telemetry, data and voice.
EIRP (Effective Isotropic Radiated Power) In a given direction, the gain of a transmitting antenna multiplied by the net power accepted by the antenna from the connected transmitter.
G/T (antenna gain-to-noise-temperature) The ratio of the gain to the noise temperature of the antenna. Usually the antenna-receiver system figure of merit is specified. For this case the figure of merit is the gain of the antenna divided by the system noise temperature referred to the antenna terminals. The system figure of merit at any reference plane in the RF system is the same as that taken at the antenna terminals since both the gain and system noise temperature are referred to the same reference plane at the antenna terminals.
Point-of-presence (POP) A POP is a physical interconnect location where separate telecommunications networks meet and communicate with each other.
Polarization That property of a radiated electromagnetic wave describing the time-varying direction and amplitude of the electric field vector: specifically, the figure traced as a function of time by the extremity of the vector at a fixed location in space, as observed along the direction of propagation.
Teleport A teleport is a physical location and interface between a satellite system and telecommunications networks on the ground. It includes a variety of satellite dishes, earth stations, and supporting ground equipment.
Transponder A receiver/transmitter combination which receives a signal and retransmits it at a different carrier frequency. Transponders are used in communication satellites for reradiating signals to earth stations or in spacecraft for returning ranging signals.
Uplink A ground to satellite link.


Platform Operators

The Ku-Band side of the satellite currently carries the platforms of Pittsburgh International Telecommunications, Inc (PIT), GlobeCast World TV, Glorystar, RRSat and ABS-CBN, with free-to-air and encrypted television and radio programming in a variety of languages:


Available Programming Languages (alphabetical)


C-Band Footprint

!File:G-25-C-band-cropped.jpg

Ku-Band Footprint

!File:G-25-Ku-band-cropped.jpg


References

  1. ^ Lyngsat.com satellite launch schedule
Retrieved from "https://en.wikipedia.org/w/index.php?title=Galaxy_25&oldid=128828039"