Friday, October 18, 2013

Navigation Instruments

By Carey Bourdier


Ships navigating the high seas worldwide use various types of navigational instruments and this also goes with the U.S. Navy and U.S. Coast Guard who use many navigational instruments. There are various objectives and purposes for using navigational instruments. Some of these purposes are the determination of speed and direction of the ships, the ships arrival at its port of destinations, the position where the ships are presently, and other purposes. While these days, many navigational instruments rely on electricity and many ships have on-board computer systems, navigators still use many tools that have been around for centuries. Here are just a few examples of navigation tools, both old and new.

Telescopic marine alidades are navigation instruments used in ships. These are navigational instruments used to take terrestrial bearings of the vessel. The instrument is mounted on a bearing compass or bearing compass repeater when used. It is used to obtain the bearing of the vessel and is equipped with a telescopic sight and prismatic optical system. Through the use of the telescopic marine alidade, an accurate bearing can be made of the object in the distance. This instrument helps provide accurate marine data while at sea.

Another example of navigational equipment that is interesting is the three-arm protractor. This is also instrument that is used inland, although in these days, the use of GPS is overtaking its popularity. This instrument, when used in the ships and navigating in the seas, can be the fastest way to determine the ship's location. Determination of longitude and latitude can be made through calculations with data extracted through the use of the instrument. Other tools, like navigational charts, are used with this instrument. Knowing how to use this tool is certainly beneficial as electrical equipment in a ship can fail, and it's best to know how to navigate with and without electronic aids.

Other equipment such as binoculars and telescopes also are used in navigation. These are optical instruments that are used so that when a person looks through the instrument, objects will look bigger. A binocular is two similar telescopes mounted together and the person using will use both eyes. Telescopes are only with one scope and the person will only use one eye with the instrument. Three dimensional images will be seen with binoculars since both eyes are used. With the use of binoculars, images are more natural, and the object is bigger. Objects that are very far can still look natural and the image is clear and bigger despite the distance. However, high-powered telescopes can be mounted to a ship and these provide excellent viewing of faraway objects.

In general navigation, navigational sextants are instruments used with great importance. Measuring angles between two objects can be made, and this is where sextants are used. This is a navigational instrument with two mirrors used and the first is used to view the horizon. Light from the sun and its reflection is used, and this is the function of the second mirror because it is movable. The instrument's scale will then be used when reading the angle between the two.

Electronic equipment like sonar and radar are also very important in navigation. These are instruments used to determine and locate objects through the echo of signals bounced off the object. Radar is used with radio waves as medium and sonar with sound waves. Inland or through the air, radio waves are used and in the seas or underwater, sound waves are the mediums used. Radar and sonar have different applications because of the different type of energy used, radio waves for radar and sound waves for sonar.




About the Author:



No comments:

Post a Comment