Lesson 20: Advanced Navigation Systems “Getting Acquainted Lecture” Instructor Bio: Commissioned May, 1993; NROTC Unit, IIT Reported to Hue City (CG-66) homeported in Mayport, FL for a 42 mos tour 24 mos - Engineering Dept (Auxiliaries Officer & Damage Control Assistant) 18 mos - Operations Dept (Air Warfare Officer/BW Flag Liaison Officer) Command Employment (while aboard Hue City) 1995 Med Deployment 95-2 with USS Theodore Roosevelt 1996 Baltops ‘96 (Scandinavian countries) 1997 Med Deployment 97-2 with USS John F. Kennedy Midshipmen Cruises (emphasize student contribution to course) CV (CV 63) - Secrest Tico’s (LKE, VLG) -Waterston, Pope, Sullivan Burkes (DDG 61) - Kuckel OH Perry (FFG 61) - Phillips LHA/LHD (LSD 44) - Fink, Sutherland AOE (AOE-8) - Hertel Review Syllabus: Course objectives Course resources (webpage, Textbook, Workbook) Case studies - provide vivid and intriguing examples of the the fundamental principles taught in this course. 11/28/201811/28/2018

Lesson 20: Advanced Navigation Systems AGENDA: NAVSTAR Global Positioning System Ship’s Inertial Navigation Systems (SINS) Bottom Contour Navigation LORAN-C Electronic Charts (Raster & Vector) Navigation Sensor System Interface (NAVSSI) Applicable reading: Hobbs pp. 495-555.

NAVSTAR Global Positioning System (GPS) GPS = Global Positioning System A space based, all-weather, jam resistant, continuous operation, worldwide radio navigation system. Provides extremely accurate 3D location data as well as velocity and time. 3 LOPs provide a Lat. & Long. 4 LOPs provide Lat., Long. & Altitude

NAVSTAR GPS Specifications Frequency: 1227 MHz, 1575 MHz Range: Worldwide Accuracy: next slide 3 Types: SPS- Standard Positioning Service PPS-Precise Positioning Service Differential GPS- for military only

NAVSTAR GPS Accuracy 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 Uses Civilian Uses Marine Navigation Law Enforcement Hydrographic surveying Search and Rescue Collision avoidance Military Uses Marine Navigation Air Navigation Rendezvous Close Air Support Mine Warfare Unmanned Aerial Vehicles (UAVs)

Differential GPS A receiving station located at a fixed, known location receives fix information from GPS. The fix obtained from GPS is compared to the known location of the station. Any difference between these two is due to GPS error.

Differential GPS GPS error information is then transmitted to vessels operating in the area. The resulting fix accuracy is 2-5 meters using the differential technique Requires more than 1 receiver

GPS Advantages Disadvantages Vulnerable to Attack Continuous Coverage (regardless of weather) worldwide coverage 3-D locator Precise Timing Standard Disadvantages Vulnerable to Attack

Inertial Navigation Systems Inertial Navigation: the process of directing the movements of a vessel based on sensed accelerations in known spatial directions. System uses: Gyroscopes Accelerometers Electronic computers

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

Inertial Navigation Systems Two types: SINS (Ship’s Inertial Navigation System) first used in 1960s getting phased out must be reset periodically ESGN (Electrostatic Gyroscopic Navigation) operates in a near perfect vacuum rotor is solely supported by an electrostatic field essentially frictionless resets only required once every 30 days

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.

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

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

LORAN (Long Range Navigation) Over the years, many ground based electronic navigation systems were developed prior to satellite based systems becoming possible. Most of these have been taken out of service, but LORAN still enjoys popularity and is still widely used.

LORAN (cont) The operating principles of the system are similar to those now used by GPS. Ground stations, at known locations, transmit signals at a predetermined time. These signals are received by vessels at sea, and the time delay is used to form a range LOP.

LORAN (cont) First established in 1957. Theory-hyperbolic LOPs based on time differences between master and secondary stations. Run by the Coast Guard Frequency: 100 kHz (LF) Range: 1200 nm Accuracy: 200-500 yds

Electronic Charts Electronic Chart Display Systems (ECDS) Raster Chart Display Systems (RCDS)

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.

Homework Ch. 30 Section 1: 1 Section 2: 1, 5, 6, 9 Ch. 31 #4c, 5, 6