Where two lines of position intersect a fix is establishes. This can be accomplished by taking the bearing of two or more known landmarks and plotting the resultant line of position or circle of position on a chart. The basic technique of the navigator is to derive a position and then plot that position on a chart. Ptolemy (90-168) a Greek mathematician, geographer, and astronomer assigned coordinates to all the places and geographic features he knew in a grid that spanned the globe ( latitude and longitude). By knowing the speed and time of travel and after compensating for the effect of winds or currents, an estimated position is derived. On water a chip log and sand glass were used to measure the speed the ship was traveling. On land, paces could be counted or by using an odometer. The course was determined by Sun, Moon, stars and planets as reference points and later, by the compass. Dead reckoning allows a navigator to deduce position by advancing plotting the position of a vassal on a chart using the course and the distance traveled. Where landmarks are not visible, other techniques must be used. While the exact age of these clay tables is unknown they are believed to date from between 3,800 B.C. Some of the earliest known maps are clay tablets from Babylonian (modern Iraq). Maps pre-date virtually all other forms of written communication. Man first navigated by using landmarks, local knowledge and maps. The Western Civilization developed a system of navigation based on mathematics, scientific principles and navigational aids such as the map and compass. The ancient Norsemen navigated by understanding the migration pattern of birds and whales. The Polynesian Navigators or palu of Micronesia routinely crossed thousands of miles of open ocean, to tiny inhabited islands, using only their own senses and knowledge, passed by oral tradition, from navigator to apprentice. A harbor pilot is someone with extensive knowledge of a body of water that guides a ship through the narrow, shallow and dangerous coastal waters between a harbor and the open sea.Īs civilization grew and man began to explore his surrounding and began trading with distant lands, several different types of navigation were developed. These types of charts depict obstacles that must be avoided and special navigational aids used on the water or in the air. A nautical chart is normally used on sea and an aeronautical chart is used in the air. A map is normally used to navigate on land and depicts surface features such as roads, cities, rivers and lakes. Our highway system has many aids to navigation in the form of signs to aid us. This simple form of navigation as known as pilotage. As we travel further from home, we may use a map (or on-line services) to plot a course to a destination. We even have navigational aid to assist us in the form of street names and house and building numbers. An example would be traveling from your home each day to your school or office. Simple navigation begins with traveling around in familiar territory.
#LEWIS AND CLARK EXPEDITION NAVIGATION TOOLS HOW TO#
This page does not attempt to teach you how to navigate. This page also touches a little on surveying which is "the technique and science of accurately determining the terrestrial or three-dimensional space position of points and the distances and angles between them". This site explores some of the many tools and navigational aids that have been developed through the ages and some of the explorers and inventors that have contributed to our knowledge about our planet and its moon. Please let me know of any broken links or other mistakes by contacting me at is the science of determination of position and direction on or above the surface of the Earth.