How Technology in Navigation Help to Decrease Navy Problems - Essay Example

How technology in navigation help to decrease navy problems Name Tutors name Subject Date Navigation is a process of controlling and examining the movement of a vessel from one point to another. Navigation techniques involve finding the navigators’ position and comparing it to know locations. Marine navigation is the science of finding a way in water. This science has been used by sailors over a long period of time for movement from point A to point B in water. The main concepts used in marine navigation are latitude and longitude. Latitude is the angular distance from north to south of the earths equator. It is measured in degrees from the equator which is 0o and 90o to the north and South Pole. Longitude is the angular distance from east to west of prime meridian (Sonnenberg, 1988). It ranges from 0o at prime meridian to 180o east to west. Signposts in water assist the vessels in understand the course and direction it is heading to. The signpost will tell the navigator where the vessel is, where to go next from the point it has reached, know where it has come from and know how to move to the next point. The posts are visible in water and costal area and they include lighthouses, lightships, beacons, and buoys. The most commonly used are buoyage. In the daytime, the posts are identified by observing the location, shape, color scheme, and auxiliary features. During the night, light is used to identify and asserts it purpose. There are 6 types of navigation buoys, namely Lateral, Cardinal, Isolated danger, Safe water, New wreck, and Special. The position of the lateral buoys defines the channel borders and the direction. There are four cardinal buoys and they all show the safe side from a dangerous point with an approximated bearing. Marks indicating isolated danger show the dangerous bath, contrary to cardinal buoys. Special buoys are normally yellow and they indicate pipelines or location used for special purposes. For a person to be able to navigate, he must first be able to read nautical chart, knowing several rules for navigation, being able to plot a course on a nautical chart, following a plotted way and being able to get a fix on nautical chart by use of marine electronics (Sonnenberg, 1988). A nautical chart is a map showing the roads in water. It has all the information needed for sailing such as where the land is, the depth of the water, dangerous areas, landmarks, and lights (Sonnenberg, 1988). It also has a compass to show the right bearing needed, a distance scale and a longitude and latitude scale for checking the location. Once the nautical chart is understood, the course in the water can be plotted so that the sheep can be steered in good water. Plotting is done by drawing the lines on the chart in good areas from one location to another and using a compass to show the direction. The vessel should follow the plotted course and to ensure that the plotted course is followed, the captain should regularly try to find the point the vessel is and obtain a fix. If the natural forces such as ocean currents and tides throw off the vessel outside the course, the correction should be made while the vessel is moving to ensure that it stays on course. Underwater navigation is aided by two forms of techniques, which are natural navigation techniques and orienteering. Natural navigation techniques involve the use of natural features like sunlight, water movement, bottom composition, contour, and noise. Orienteering is also known as compass navigation; it is the use of compasses and other techniques such as kick cycles, time, and air consumption. In natural navigation, landmarks are topographic features that can be noted and are used to identify position and direction in water. The Features are significant if it is possible to see the next landmark on the way after leaving the first one. Landmarks are permanent features and they include ridges, boulders, and wrecks. Depth and depth variation aids in navigation in that the slope of the ocean underground shows the direction towards the shore, in specific, if the underground is made up of soft or loose material and it has not broken up largely. Deep contours moving parallel to the coastline shows a slope dipping away from the shore and is used to maintain the distance in relation to the shore. If the depth and clarity of the water allow the sun to give enough variation in brightness, it will show the direction of the sun and this will aid in showing the direction (Farrell and Barth, 1998). If the current direction is know, they are significant in showing the direction. Surge direction is simply the same as the wave but they are felt in depths where the wave direction can no longer be felt. It is significant when the offshore wave direction is known and doesn’t change during diving. Ripple patterns on the sand, mud or gravel at the underwater shows that it has been affected by the movement of the waves. The movement of the waves causes the bottom particles to be moved backward and forward in the direction the waves are moving at. The movement creates a ripple pattern that shows the wave direction on the surface. Different areas in underwater has different ecologies. If a diver is aware of the ecological perspective of the area, it will use the variation to find direction. Compass navigation shows the direction using a magnetic filed which is the same as that of the earth. It is the most reliable and consistent means and it is not affected by the visibility, pressure, or water, the compass always points at the right direction irrespective of the condition surrounding. Several equipments has been developed to aid in underwater navigation, these include magnetic compass, marine sextant, compass boards, and hand-held sonar. When using the compass, it must be held perfectly horizontally so that the needle can rotate easily. Divers should check the bearings frequently to avoid missing the course. Marine sextant measures the angle formed at the divers’ eye amid the celestial body and sensible horizon (Farrell and Barth, 1998). The equipment has two mirrors know as index mirror and horizon mirror, the mirrors are silvered and once the light from the celestial object strikes the index mirror, it will be reflected to the horizontal glass and to the divers’ eye. Hand-held sonar is equipment that uses sound propagation in navigation to communicate or detect objects under the water. The equipment is used to detect acoustic location and measuring echo characteristics of the targets. Hand-held sonar was used before the radar was invented. The modern equipments that aid in navigation include dead reckoning, pilotage, and celestial navigation. The electronic navigation involves the use of radio navigation, radar navigation, and satellite navigation. Radio navigation functions by use of radio waves to determine the location using radio direction finding systems or Decca and Omega systems. Satellite uses systems such as GPS to determine the location. Radar stands for radio detection and ranging. The equipment measures the distance to an object through measuring the time needed for a radio signal to travel from a transmitter to the material and go back (Sweet, 2003). Marine radars use directional antennas that mean they can establish the object bearing. The radar scanner fires a magnetron with high voltage through a waveguide and transmitted by antenna. One antenna is used to transmit and receive a signal. This information will be used to determine arcs of position and line of position on chart. The radars in ships are equipped with Automatic Radar Plotting Aid (ARPA) which allows ranges and content bearing to be scrutinized. Radar tracks land masses, boats and other objects. The simple navigation example involves two coordinate’s frames, body frame and navigation frame. Body frame is denoted by u, v, w, u axis pint forward, w axis points down while v points to the right hand. The navigation frame coordinate is denoted by n, e, d, and the axes points north east and down. Navigation and body frame coordinate system can be aligned by rotating the navigation frame by an angle Ψ about its u axis. Dead reckoning is a navigation that requires a direction indicator and a speed indicator. The distance travelled is determined by multiplying the average speed together with a given heading by the time of travel. The distance is plotted from the reference point along the measured heading to establish the expected point. There are two types of inertial systems, stable platform system and Strapdown system. In a stable platform system, the inertial sensors are fixed on the platform that is separated from any external rotational motion. To achieve this, the platform is mounted by use of gimbals that allow the platform to move in the 3 axes. The gyroscopes of the platform detect any platform movement. To monitor the orientation of the object, the angles between the adjacent gimbals is read by use of angle pick-offs. To calculate the location of the device, the signals from the mounted platform accelerometers are integrated twice (Oliver, 2007). In Strapdown system, the inertia sensors are mounted firmly onto the device and the output quantities are measured in the body frame (Oliver, 2007). To monitor the orientation, the signals emanating from the rate gyroscopes are integrated. To track a certain location, the 3 accelerometer signals are resolved into global coordinates by use of known orientation as established by the integration of gyro signals (Oliver, 2007). Global Poisoning System (GPS) is a constellation of satellites in the earths orbit, the satellites is one of the electronic form of navigation. The GPS satellites send signals to the equipment on the ground. The receiving equipments should view the sky directly; any obstruction will interfere with the signals. The satellite can tell the precise position of the object through a process called trilateration. In GPS, the GPS unit communicates with 3 satellites in sight using high frequency low power radio signals and then calculates the distance between the 3 satellite and the unit (Oliver, 2007). This process will give an accurate location of an object. In navigation once the GPS locate the position of the object, it can now determine map routes, speeds and other areas. The indoor performance of the GPS should be improved. This can be done through mitigating the multipath propagation effects since satellite signals are affected by obstruction. The GPS objects should have signals strength that cannot be interfered with the steel objects and titanium. The advantages of navigation technology is that little time is spend in detecting the objects and finding the course, the radar calculate the distances between the objects within microseconds and gives accurate distance. Unlike the old technology that uses trial and error in finding the course, the new technology by use GPS provide continuous and accurate position fixing with a small error of 10m within the course. Technology has adequate control, monitoring, and evaluation. The use of experts system reduces human error and provides support for decision making. The use of signposting will help the vessels follow the best course since the post shows the dangerous course and the best course; it also indicates the location of the costal line. In conclusion, marine navigation technology has assisted in decreasing the navy problems in several ways. The Signposts assist the navigators in understand the course and direction it is heading to. It tells the navigator where the vessel is, where to go next from the point it has reached, know where it has come from and know how to move to the next point. For a diver to be successful in underwater, he must apply to form of techniques that is natural navigation techniques and orienteering. Natural navigation techniques involve the use of natural features like sunlight, water movement, bottom composition, contour, and noise. Orienteering is the use of compasses and other techniques such as kick cycles, time, and air consumption. Modern navigation use modern equipments such as dead reckoning, pilotage, and celestial navigation. The electronic navigation involves the use of radio navigation, radar navigation, and satellite navigation. Satellite uses systems such as GPS to determine the location while radar measures the distance to an object through measuring the time needed for a radio signal to travel from a transmitter to the material and go back. This technology has assisted navigation minimizing the time spend in detecting other object or coastline and finding the accurate position of the required landmark or object. References Sonnenberg, J. (1988), Radar and electronic navigation, 6th. Ed, New York: Butterworth & Co. Farrell, J. and Barth, M (1998), the global positioning system & inertial navigation. New York: McGrow-Hill Sweet, R (2003), GPS for marines. United States of America: The McGrow-Hill companies OliverJ.W. (2007), An introduction to inertial navigation, technical report, London: Cambridge university press. Read More