1 / 24

Lesson 14: Advanced Navigation Systems

Lesson 14: Advanced Navigation Systems. Lesson 20: Advanced Navigation Systems. AGENDA: NAVSTAR Global Positioning System (GPS) Inertial Navigation Systems (INS) Bottom Contour Navigation Electronic Charts (Raster & Vector) Navigation Sensor System Interface (NAVSSI)

mburnette
Download Presentation

Lesson 14: Advanced Navigation Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Lesson 14: AdvancedNavigation Systems

  2. Lesson 20: Advanced Navigation Systems • AGENDA: • NAVSTAR Global Positioning System (GPS) • Inertial Navigation Systems (INS) • Bottom Contour Navigation • Electronic Charts (Raster & Vector) • Navigation Sensor System Interface (NAVSSI) • Applicable reading: Hobbs pp. 540-555.

  3. NAVSTAR Global Positioning System (GPS) • GPS = Global Positioning System • all-weather, jam resistant, continuous operation, real-time, passive, worldwide radio navigation system. • Provides: • Extremely accurate 3D position data • Extremely accurate velocity data • Precise timing services • 3 LOPs provide a Lat. & Long • 4 LOPs provide Lat., Long. & Altitude

  4. Civilian Uses Marine Navigation Law Enforcement Hydrographic surveying Search and Rescue Collision avoidance Military Uses Rendezvous Close Air Support Mine Warfare Unmanned Aerial Vehicles (UAV/s) NAVSTAR GPS Uses WRN-6

  5. WRN-6

  6. Differential GPS (DGPS) • A receiving station located at a fixed, known location receives position data from several GPS satellites. • The data obtained from GPS is compared to the known location of the station. • Any difference between these two is due to GPS error. • This difference the applied to the individual GPS receiver and thus, increased positional accuracy is obtained

  7. Standard Position Service (SPS) Position: 100 m Hor. 150 m Vert. Velocity: .5 m/sec Time: 1 milli- second Precise Position Service (PPS) - Military Position: 16 m Hor. 25 m Vert. Velocity: .1 m/sec Time: 100 nano- seconds NAVSTAR GPS Accuracy

  8. Inertial Navigation System (INS) • Inertial Navigation: the process of measuring the movements of a vessel based on sensed accelerations in known spatial directions. • Gyroscopes • Accelerometers • Electronic computers

  9. Inertial Navigation Systems (cont) • Integrating acceleration gives you velocity • Integrating velocity gives you position/distance traveled • Need to compare to fix, since output is an EP! • Can go up to 30 days w/out update, in theory • Typically go no longer than 7-14 days • Types • SINS • ESGN • RLGN

  10. Inertial Navigation Systems Current position is inputted Xo Spinning gyro Known mass Accelerometer F=m*a Computer Through Differentiation we get velocity and position (V and Xf)

  11. Bottom Contour Navigation • Establishes position by using the geographic features of the ocean floor. • An echo sounder (fathometer) is used to produce a trace of the ocean floor beneath the vessel, which can be compared to a bottom contour chart to establish the ship’s position. • Can be used as a fix source, but is only accurate when large ocean floor gradients exist

  12. Bottom Contour Navigation • 2 Techniques: • Line-of-Soundings (page 567 in Hobbs) • Contour Advancement (page 568 in Hobbs)

  13. Advantages no satelites required subs=> no need to go to Periscope Depth (PD) not vulnerable Disadvantages not very accurate requires a cooperative sea bottom Bottom Contour Navigation

  14. Electronic Charts • Raster Chart Display Systems (RCDS) • Electronic Chart Display Systems (ECDS) • Not approved for Fleet use, but getting closer

  15. Navigation Sensor System Interface (NAVSSI) • Provides/Distributes NAV data (precise position, time, velocity, pitch-roll-yaw) to multiple users. • NAVSSI has been successfully installed, interfaced, and tested with WSN-5, WRN-6, EM Log, Tomahawk, Outboard, and NTCS-A. • A similar system may be integrated into your ship’s Combat Control System (CCS)

  16. Summary/Review • How does GPS work? • What is ephemeris and almanac data? • Name 3 uses of GPS. • How does differential GPS work? • How do Inertial Navigation Systems work?

  17. QUESTIONS?

More Related