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3. ARMY / Davidsonville TX station Maryland

Last modified: 27 Jun 2022, submitted by: Joker

Country: United States    Region: Maryland

Locale: rural

Latitude: 38° 57' 56" N     Longitude: -77° 19' 5" E

Area use / Military Branches: ACTIVE


3857'56"N 7640'55"W Davidsonville Secure Communications Transmitting Facility is a large geographically separated unit manned by US Army and NSA personnel The site contains 27 high power HF transmitters, 30 antennas of various types, digital microwave systems, a backup power plant, patch and test facility, a dining facility and a dormitory. The site provides HF and digital transmitter support to certain civilian and military communications systems in the national capital region, Andrews airbase and certain military units placed under very short notice.
Its receiving counterpart is mentioned at 3. ARMY / Brandywine RX station - Maryland

The current operational DoD communications system is the US Defense Satellite Communications System (DSCS). It is part of the MILitary SATellite COMmmunicatons structure comprising 3 categories:
wideband, emphasizing high capacity worldwide communications
protected, prioritizing jamming persistent features and covert communications
narrowband, emphasizing support to disadvantaged users by providing low data rate communications to small / mobile users.

DSCS provides nuc-hardened, jamming resistant, high data rate, long haul worldwide communications; supporting the total defense communications system for the Army's ground mobile forces, all Air Force's airborne terminals, all Navy task forces at sea, the White House and State Department Communications Agency and certain Spec Ops Forces.

General Characteristics:
DSCS is based on 14 satellites half of which offline and the other half operational being used in various capacities
Primary function: high-capacity military voice and data communications
Primary control: MILSATCOM Systems Directorate, Space & Missile Systems Center (SMC) at Los Angeles airbase, California
Primary contractor: Lockheed Martin Space Systems Company / Sunnyvale operations, California
Payload: 6-channel Super High Frequency (SHF) transponded system Single Channel Transponder (UHF/X crossband)
1 wideband multi-beam and 2 earth coverage receive antennas
2 transmit multi-beam, gimbaled dishes and 2 earth coverage antennas
Data capability: up to 200 Mbps

MILSTAR is a global, secure, nuclear-survivable, space-based communication system initially from the 1980s designed to perform all communication processing and network routing onboard, eliminating the need for land-based relays and reducing the chances of intercepted communications. It provided the US president, secretary of defense and the armed forces with assured, survivable satellite communications with low probability of interception and detection. The system has recently (2020) been upgraded and is currently still employed by the Department of Defense as a new integrated C2 S-band system for the new MILSTAR Advanced Extreme High Frequency (AEHF) satellite system.

General Characteristics:
Primary function: survivable and protected communications
Primary contractor: Lockheed Martin
Payload: Low and Medium Data Rate, (L/MDR) and UHF
LDR: Earth Coverage (uplink & downlink), Agile Beams (5 uplink, 1 downlink), Spot Beams (2 narrow, 1 wide),
MDR: 2 Nulling, 6 Distributed User Coverage Area
Data capability: LDR: 75 bps - 2.4 kps / MDR: 4.8 kps1.544 Mbps

- AFSATCOM was a USAF network of ground and space systems allowing rapid dissemination of communications worldwide. AFSATCOM's creation was during the height of the Cold War to guarantee that Emergency Action Messages (EAM) would be received by Strategic Air Command nuclear forces. AFSATCOM operations used transponders from naval FLTSATCOM satellites for the EAM's.

- FLTSATCOM was a US Space Force satellite communication system which was used for Ultra High Frequency (UHF) communications between Navy ships, submarines, aircraft and shore stations. It became operational in 1981 and consisted of 8 satellites in geostationary orbit. The transponders on these satellites were simple repeaters without authentication or control over what they retransmitted. The FLTSATCOM satellites were replaced by LEASAT and then gradually replaced by the UFO satellites.

- LEAsed SATellite (LEASAT) system consisted of 3 spacecraft leased from Hughes, which was also the manufacturer. The final launch of the LEASAT program occurred in early 1990 on the Space Shuttle. Each LEASAT spacecraft provided 13 UHF communication channels and a 500 Kc wideband channel. The satellites provided high-priority global communications for the fleet, the USAF Strategic Airborne Command and some Army combat units. Naval Space Command served as the operational manager for the system. The last operational spacecraft among the constellation of LEASAT communications satellites used for over a decade by the US military was retired in February 1998.

- The Ultra High Frequency Follow-On (UFO) satellite system also by Hughes replaced FLTSATCOM and consisted of 11 satellites controlled by 10th Space Operations Squadron (Space Delta 8) at Naval Base Ventura County, California. The ground terminal segment consists of equipment and resident personnel at existing satellite communication stations. These satellites have been replaced by the combined DSCS and MILSTAR AEHF systems.

Provision of services for future systems:
As the current operational systems have a life cycle of appx 14-18 years replacing systems need to be developed and acquired. Studies are in development to choose from these options. '
- Commercial Service The appropriate choice when it is technically possible to provide the required services in an operationally acceptable manner. It is less expensive compared to using a military-owned system and the ideal solution for fixed users whose locations and longterm needs are known and predictable.

- Commercial Acquired, Military Owned
This is a commercial service acquired using commercial procurement practices, owned and operated by the DoD. It is economically advantageous to provide access to commercial-like services at military frequencies, when and where required. It is one of the services needed by forces that may deploy worldwide on very short notice. DoD ownership provides the necessary rapid response to changing service demands. However, use of commercial procurement practices may not provide the highest levels of survivability or protection on such systems.

- Military Acquired and Owned
Certain characteristics will be needed for the future. Survivability features, such as nuc hardening, anti-jam protection. low probability of intercept and detection and global assured access are not easily provided within the context of a commercial procurement. Only a militarily-acquired and militarily-owned system can provide this type of service.

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