The NAVSTAR Global Positioning System (GPS) is a space-based radio navigation and positioning system that will provide extremely accurate three-dimensional position and velocity information as well as precise time to suitably equipped users worldwide. GPS consists of three major segments: space, control, and user equipment.

GPS will provide worldwide precision navigation and time to U.S. military forces and their allies. Military forces are required to know their position in order to enhance command and control, coordinate battle tactics and support, engage in strategic and tactical warfare, maneuver efficiently on the battlefield and at sea, provide accurate and timely fire support, and facilitate combat support operations. In addition, knowledge of exact positions and time is essential for reconnaissance and intelligence missions. A worldwide positioning and navigation system can increase both accuracy and availability of current weapon systems, thus increasing their effectiveness and acting as a force enhancement.

The GPS Program is a multiservice effort, as directed by the Department of Defense. The Air Force has been designated the executive service for program development. NCCOSC's RDT&E Division Detachment serves as the technical and field staff of the Navy GPS Program Office, providing both the Navy Deputy at the Joint Program Office and a significant portion of technical expertise in the development of the GPS User Equipment. The Detachment maintains simulation and modeling capability for equipment validation/certification, SSA test, and accuracy and error analysis in both basic and differential operations.

GPS/Electrically Suspended Gyro Navigator (ESGN)

Program accomplishments during CY 93 included the following:

Completed installation, checkout, and training on a Pacific Fleet SSN 637 Class Fast Attack Submarine at Mare Island Shipyard in Vallejo, CA. This installation consisted of the addition of GPS/ESGN and GPS/ precise time interfaces to the existing AN/WRN-6 configuration on board.

AN/WRN-6 Equipment Suite

Program accomplishments in CY 94 included the following:

Delivered, installed, and verified operation of a keyed AN/WRN-6 receiver to Research Vessel RV Knorr in support of Woods Hole Oceanographic Institute project in Jacksonville, FL.

Successfully installed AN/WRN-6 equipment suites aboard four amphibious ships, in support of the AN/KSQ-1 (PLARS) DT IIA testing for the Naval Surface Warfare Center Coastal Systems Station, Panama City, FL. Provided technical support of large-scale, at-sea amphibious exercises to validate operation and usability. Trained ships' force personnel in the operation and maintenance of the GPS user equipment. The installation, complicated at-sea amphibious exercises, and deinstallation were successfully carried out in a very brief time window.

Precision Lightweight GPS Receiver (PLGR)

Program accomplishments during CY 94 included the following:

Received the first shipment of PLGRs for fleet distribution.

Global Positioning System Interface Unit (GPSIU)

The Global Positioning System Interface Unit (GPSIU) integrates GPS latitude and longitude information into the Position Locating and Reporting System (PLARS) for use within the AN/KSQ-1 Amphibious Assault Direction System. The GPSIU was designed in-house and will enable GPS navigation information to be distributed to the PLARS.

Program accomplishments in CY 94 included the following:

Participated in a major 1-month Navy and Marine amphibious assault exercise at Camp Pendleton, CA to aid in installing and testing the NRaD-developed GPSIUs. The GPSIU integrates GPS latitude and longitude information into the PLARS for use within the AN/KSQ-1 Amphibious Assault Direction System. Results showed that the GPSIU enhanced the performance of the PLARS significantly.

Standoff Land Attack Missile (SLAM) GPS

Program accomplishments during CY 94 included the following:

Installed an NRaD-developed SLAM GPS initialization system aboard USS George Washington (CVN 73) in Norfolk, VA. Trained ship's personnel on the proper operation of the system. Nearly every carrier has had one of these systems installed.


The Ring Laser Gyro Navigator (RLGN) is the next-generation inertial navigation system under development for surface ships. NRaD is responsible for development and transition of the RLGN into the Fleet and for subsequent product improvements. NRaD also provides an extended performance capability, a significantly improved reliability, and a much lower life-cycle cost.

Program accomplishments during CY 94 included the following:

Completed development of a RLGN system specification for U.S. Navy submarine and surface combatant platform applications.


NCCOSC's RDT&E Division Detachment is the technical agent for the Naval Oceanographic Office with total responsibility for the design, development, test, and evaluation of the complete shipboard mission equipment for the Ocean Survey Program (OSP).
The mission survey system is a highly complex, integrated navigation, bathymetric, and data refinement system that produces high-accuracy charts of bathymetry, gravity, magnetics, and other geophysical parameters in support of the Trident Fleet Ballistic Missile Submarine Program. The system is operational on four deep-ocean survey ships: the USNS Maury (T-AGS 39), USNS Tanner (T-AGS 40), USNS H. H. Hess (T-AGS 38), and USNS Wyman (T-AGS 34).

The OSP has a BRICKBAT 01 priority, the Navy's highest, and is in a continuous evolutionary phase to maintain the highest state-of-the-art in survey capability and productivity. The program is providing new challenges in ocean bottom characterization, shallow-water coastal surveys, and bistatic bathymetry to meet future requirements.

A 4500-square-foot Systems Integration Laboratory (SIL) supports in-house OSP hardware and software development. Three major laboratory areas are in operation for bathymetric refinement, multibeam sonar, and navigation system development.

In CY 94, NRaD successfully completed the second and final at-sea TECHEVAL of the major Ocean Survey System upgrade aboard the USNS Wyman. This upgrade increases survey system capability and provides NAVOCEANO with their first multimission-capable survey platform.

The upgrade was designed and developed to improve the operability, productivity, reliability, and maintainability of the on board system. The system collects data and produces accurate charts of bathymetry, gravity, and other oceanographic parameters for use by the fleet.

The upgrade includes changes to both the system hardware and software. Aged computers and associated peripherals were replaced with state-of-the-art computers and workstations.

The upgrade includes a new Mission Control and Processing Subsystem (MCAPS). This consists of three workstation systems to improve both real-time and post-time data analysis and processing capabilities for central control of the system computers.

The MCAPS has a new Survey Control System (SCS) three-monitor workstation that permits the system operator to remotely control the navigation and wide swath multibeam sonar programs. The SCS also has new and improved displays facilitating efficient survey management.

The new System Analysis Station (SAS) is also part of the MCAPS. This two monitor workstation has displays for on-line system performance analysis and control of the system plotter functions.

The DRS has more efficient and flexible post-time data analysis and processing than was possible with the older Bathymetric Replacement System that produces the final shipboard data products.

The wide swath multibeam sonar system has an improved shallow-water capability that allows recording of depths to 20 fathoms. The previous minimum usable depth was 100 fathoms. The cross track coverage of the multibeam sonar was also increased from 90 to 120 degrees for depths of less than 2500 fathoms, decreasing to 90 degrees for deeper depths.

A new Backscatter System operates in parallel with the wide swath sonar receivers. It records the acoustic data from the sonar receivers for post-time generation of high-resolution images on the ocean bottom.

The system upgrade includes various other improvements including:

  1. a. An upgraded Ship Attitude Data Converter (SADC) that receives attitude data in synchro form from various sensors and distributes the data in synchro and digital format. The SADC also provides simulated dynamic attitude data to support system testing when the ship is dockside.
  2. b. An upgraded Current Profiler System (CPS) has improved operability capabilities. The CPS develops a velocity profile of the water currents beneath the ship and measures the ship's velocity.
  3. c. An upgraded Narrow Beam Sonar System provides improved performance for the single beam sonar system utilizing a new programmable transceiver and digital signal processor.
  4. d. An upgraded Sound Velocity System has improved operability and automatic transfer of sound velocity data to the multibeam sonar system.
  5. e. Upgraded navigation system software offers improved operability and eliminates the need for hard copy outputs.
  6. f. A new 60-Hz and 400-Hz regulated and uninterruptible power system is required to support the system upgrade.


The Navigation Sensor System Interface (NAVSSI) is designed to integrate shipboard navigation sensors and systems and to provide a single best source of navigation information to all users. NRaD is responsible for development and preplanned product improvement of the NAVSSI including incorporation of ship navigation planning aids, digital nautical charts, plotting capabilities, addition of navigation sources and users, and accuracy improvements.

Program accomplishments during CY 94 included the following:

Completed development of a NAVSSI module to allow NAVSSI availability at any Navy Tactical Control System-Afloat (NTCS-A) terminal. This is a major step required to fully integrate the NAVSSI into the Joint Maritime Command Information System (JMCIS) program.

NAVSSI Surface Ship Block 0. Received Milestone IIIa approval. Thirty-five systems are now scheduled for procurement and installation on cruisers and destroyers.


Program accomplishments in CY 94 included the following:

Control Display Navigation Unit (CDNU) Software Build. Successfully tested CDNU software build 1 for the UH-1N helicopter in the NRaD CDNU development and test facility.


Program accomplishments in CY 94 included the following:

Data Refinement System (DRS) Installation and Testing. Completed the installation and testing of a DRS at the United Kingdom Hydrographic Office in Taunton, England. In addition, NRaD provided training to UK personnel on operation of the system. The DRS will be used by the UK Hydrographic Office to refine the bathymetric data that will be collected and preprocessed on board the UK Ocean Survey Vessel that will be equipped with the bathymetric survey system developed by NRaD Warminster.