(U) United States Nuclear Detonation Detection System (USNDS)

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)

Overview: (U)
(U) The United States Nuclear Detonation (NUDET) Detection System (USNDS) is designed to detect, locate, and report nuclear detonations (NUDETs) in the earth's atmosphere and near space in near real-time.  The system is designed to support nuclear force management, integrated tactical warning and attack assessment, and test ban treaty monitoring.  The system includes space based sensors and ground mission processing systems.  The sensor payloads use NAVSTAR Global Positioning System (GPS) navigation satellites, and Defense Support Program (DSP) satellites as host platforms. This description is restricted to the GPS portion of the USNDS system.  USNDS employs both fixed site and mobile ground processing to report information to the various USNDS users.

Description: (U)
(U) The Block IIR GPS/NDS system consists of optical, x-ray/dosimeter, and electro-magnetic pulse (EMP) sensors.  The optical sensor measures atmospheric light signatures and provides location and yield measurements.  The EMP sensor measures atmospheric EMP phenomena to provide improved location accuracy and profile data.  The X-ray sensor measures the exo-atmospheric X-ray spectrum while the dosimeter measures high energy proton and electron activities.  GPS/NDS collects, processes, stores, and formats event data for transmission via an L3 communications link.  In addition, fixed site ground operators can command S-band memory read-outs of NDS data.  

(U) GPS/NDS information is received via two NDS ground processing systems.  The Integrated Correlation and Display System (ICADS) is the fixed site ground processing system.  ICADS supports two key NDS missions: 1) The Integrated Tactical Warning/Attack Assessment (ITW/AA) mission of the North American Air Defense (NORAD)/USSPACECOM; and 2) The nuclear test ban treaty monitoring mission of the Air Force Technical Applications Center (AFTAC).  The Ground NDS Terminals (GNT) provide mobile and endurable capabilities to support the ITW/AA mission of NORAD/USSPACECOM and the Nuclear Force Management Mission of USSTRATCOM.

(U) The GPS/NDS contains three upgrades: Block IIA, IIR, and IIF.  Each upgrade will have a combination of upgraded optics, EMP, and X-ray sensors.  The NDS payload is called the Global Burst Detector (GBD).

(U)  Block IIA and Block IIR GBD configurations:
 -- (U)  Burst Detector Processor (BDP) - processes data from the various sensors
 -- (U)  Optical sensor (BDY) - detects the optical time signature of NUDET bursts
 -- (U)  X-Ray sensor (BDX) or Dosimeter (BDD) - detects exo-atmospheric NUDETs (Combined into one unit (CXD) starting on GPS IIR Space Vehicle (SV #13)
 -- (U)  EMP sensor (WSRP-IIA, BDW-IIR) - provides accurate location of NUDETs
 -- (U)  EMP high and low band antennas
 -- (U)  Burst Detector Analysis (BDA) - processes sensor background data starting on GPS IIR (SV #13)
 -- (U)  Deployable UHF receive and a S-band transmit BDA antennas, starting on SV #13.

(U)  GPS Block IIF NDS payload configuration:
 -- (U)  CXD, BDP, and BDA
 -- (U)  Differences:
 -- (U)  BDY enhanced (BDYE) starting on GPS IIF SV #7
 -- (U)  EMP sensor not part of current IIF configuration.

User Impact: (U)
(U) The GPS/NDS system supports the Nuclear Force Management, Integrated Tactical Warning and Attack Assessment (ITW/AA), and test ban treaty monitoring mission areas.  These satellites are the only United States capability to support those mission areas when detecting, locating, and reporting NUDETs in the earth's atmosphere and near space in near real-time.

Programmatics: (U)
(U) Programmed.
	(U) IOC: 10/1997 (1QFY1998).
		(U)  ICADS Build 3 IOC for ITW/AA was declared 3QFY95.  
(U)  Delivered GNT Phase I (Block II/IIA) to users 2QFY96.
(U)  Lost 1st GPS Block IIR in launch failure 2QFY97.
(U)  GNT Phase I Operational Turnover Complete 1QFY98.
(U)  GNT Phase II (Block IIR)Delivery 2QFY98.
(U)  ICADS Build 4 Acceptance Test 2QFY98.
(U)  ICADS Build 5 Critical Design Review 1QFY99 TBD: 02/1997 (2QFY1997).

Related Initiatives: (U)
(U) DSP/NDS, NBC Detection, SBIRS High NUDET Package

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) NDS

Road Map Placements: (U)
(U) SURVEILLANCE AND WARNING.

Lead Office: (U)
(U) Air Force.

Date of Information: (U)
01 October 1997

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)