Phase IV

15° W longitude, and 10 LEASAT (L-2) is positioned at 72.5° E longitude (figure 2-6). Each LEASAT provides 13 communications channels using 9 transmitters. There are 7 25-kHz UHF downlink channels, 1 500-kHz wideband channel, and 5 5-kHz channels. The 500-kHz channel and the 725- kHz channels are leased by the Navy. One of the 725- kHz UHF downlink channels is the downlink for the Fleet Satellite Broadcast. The broadcast uplink is SHF, with translation to UHF taking place in the satellite. The remaining 625- kHz channels function as direct-relay channels with several repeaters. Currently, the LEASAT channels provide for the following subsystems: Channel 1 for Fleet Satellite Broadcast transmissions; 1 25-kHz channel for SSIXS communications; 1 25-kHz channel for ASWIXS com- munications; and 2 25-kHz channels for subsystems that transmit or receive via DAMA (Demand Assigned M u l t i p l e A c c e s s ) ( f o r e x a m p l e, CUDIXS/NAVMACS, TACINTEL, and secure voice). PHASE IV Operations Desert Shield/Desert Storm reinforced the requirement for and greatly accelerated the introduction of SHF SATCOM capability on aircraft carriers and amphibious flagships to satisfy minimum tactical command and control (C2), intelligence and warfighting communications requirements while improving Joint and NATO/Allied communications interoperability. To meet the urgent operational requirement, the U.S. Navy obtained and modified U.S. Air Force AN/TSC-93B Ground Mobile Forces (GMF) SHF SATCOM vans for installation on aircraft carriers and amphibious flagships deploying to the Persian Gulf. The modified vans were coupled with the AN/WSC-6(V) standard U.S. Navy SHF stabilized antenna system, the SURTASS modem, 2 low speed time division multiplexer (LSTDMs), and additional Figure 2-6.—LEASAT coverage areas. 2-6