Finding your way around. Getting from point A to point B.
is a field of study that focuses on the process of monitoring and
controlling the movement of a craft or vehicle from one place to another.
The field of navigation includes four general categories: land navigation,
, aeronautic navigation, and
. It is also
the term of art used for the specialized knowledge used by navigators to
perform navigation tasks. All navigational techniques involve locating the
navigator's position compared to known locations or patterns. Navigation,
in a broader sense, can refer to any skill or study that involves the
determination of position and direction. In this sense, navigation
includes orienteering and pedestrian navigation. For information about
different navigation strategies that people use, visit human navigation.
is a group of sports that requires navigational skills
using a map and compass to navigate from point to point in diverse and
usually unfamiliar terrain, and normally moving at speed. Participants are
given a topographical map, usually a specially prepared orienteering map,
which they use to find control points. Originally a training exercise in
land navigation for military officers, orienteering has developed many
variations. Among these, the oldest and the most popular is foot
orienteering. For the purposes of this article, foot orienteering serves
as a point of departure for discussion of all other variations, but almost
any sport that involves racing against a clock and requires navigation
with a map is a type of orienteering.
Map & Compass Handbook
outdoor recreational activity, in which participants use a Global
Positioning System (GPS) receiver or mobile device and other navigational
techniques to hide and seek containers, called "geocaches" or "caches", at
specific locations marked by coordinates all over the world.
Geographic Information System
is a system designed to capture, store,
manipulate, analyze, manage, and present spatial or geographic data. The
is sometimes used for
geographic information science (GIScience) to refer to the academic
discipline that studies geographic information systems and is a large
domain within the broader academic discipline of geoinformatics. What goes
beyond a GIS is a spatial data infrastructure, a concept that has no such
is a space-based radionavigation system owned by
the United States government and operated by the United States Air Force.
It is a global navigation satellite system that provides geolocation and
time information to a GPS
on or near the Earth where there is an unobstructed line of sight to four
or more GPS satellites
or estimation of the real-world geographic location of
an object, such as a radar source, mobile phone, or Internet-connected
computer terminal. In its simplest form geolocation involves the
generation of a set of geographic coordinates and is closely related to
the use of positioning systems, but its usefulness is enhanced by the use
of these coordinates to determine a meaningful location, such as a street
address. For either geolocating or positioning, the locating engine often
uses radio frequency (RF) location methods, for example Time Difference Of
Arrival (TDOA) for precision. TDOA systems often utilise mapping displays
or other geographic information system. When a GPS signal is unavailable,
geolocation applications can use information from cell towers to
triangulate the approximate position, a method that is not as accurate as
GPS but has greatly improved in recent years. This is in contrast to
earlier radiolocation technologies, for example Direction Finding where a
line of bearing to a transmitter is achieved as part of the process.
is the orientation, angular position, or attitude of an object such as a
line, plane or rigid body is part of the description of how it is placed
in the space it is in. Namely, it is the imaginary rotation that is needed
to move the object from a reference placement to its current placement. A
rotation may not be enough to reach the current placement. It may be
necessary to add an imaginary translation, called the object's location
(or position, or linear position). The location and orientation together
fully describe how the object is placed in space. The above-mentioned
imaginary rotation and translation may be thought to occur in any order,
as the orientation of an object does not change when it translates, and
its location does not change when it rotates.
is the process of calculating one's current position by using a
previously determined position, or fix, and advancing that position based
upon known or estimated speeds over elapsed time and course. The
corresponding term in biology, used to describe the processes by which
animals update their estimates of position or heading, is path
integration. Drift is the angle between the heading of the airplane and
the desired track. A is the last known position (fix, usually shown with a
circle). B is the air position (usually shown with a plus sign). C is the
DR position (usually shown with a triangle). Dead reckoning is subject to
cumulative errors. Advances in navigational aids that give accurate
information on position, in particular satellite navigation using the
Global Positioning System, have made simple dead reckoning by humans
obsolete for most purposes. However, inertial navigation systems, which
provide very accurate directional information, use dead reckoning and are
very widely applied. By analogy with their navigational use, the words
dead reckoning are also used to mean the process of estimating the value
of any variable quantity by using an earlier value and adding whatever
changes have occurred in the meantime. Often, this usage implies that the
changes are not known accurately. The earlier value and the changes may be
measured or calculated quantities. There is speculation on the origin of
the term, but no reliable information.
encompasses all of the ways in which people (and animals) orient
themselves in physical space and navigate from place to place. The basic
process of wayfinding involves four stages: Orientation is the attempt to
determine one's location, in relation to objects that may be nearby and
the desired destination. Route decision is the selection of a course of
direction to the destination. Route monitoring is checking to make sure
that the selected route is heading towards the destination. Destination
recognition is when the destination is recognized.
is a person's point-of-view perception of their area of
interaction. Although this kind of subject matter would seem most likely
to be studied by fields in the social sciences, this particular subject is
most often studied by modern day geographers. They study it to determine
subjective qualities from the public such as personal preference and
practical uses of geography like driving directions. Mass media also have
a virtually direct effect on a person's mental map of the geographical
world. The perceived geographical dimensions of a foreign nation (relative
to one's own nation) may often be heavily influenced by the amount of time
and relative news coverage that the news media may spend covering news
events from that foreign region. For instance, a person might perceive a
small island to be nearly the size of a continent, merely based on the
amount of news coverage that he or she is exposed to on a regular basis.
In psychology, the term names the information maintained in the mind of an
organism by means of which it may plan activities, select routes over
previously traveled territories, etc. The rapid traversal of a familiar
maze depends on this kind of mental map if scents or other markers laid
down by the subject are eliminated before the maze is re-run.
is a field of science devoted to the study of the
features, the inhabitants, and the phenomena of Earth.
Smarty Pins with Google
is the study of the shape and features of the surface of the Earth and
other observable astronomical objects including planets, moons, and
asteroids. The topography of an area could refer to the surface shapes and
features themselves, or a description (especially their depiction in
is the inability to orient oneself in one's
surroundings as a result of focal
disability may result from the inability to make use of selective spatial
information (e.g., environmental landmarks) or to orient by means of
specific cognitive strategies such as the ability to form a mental
representation of the environment, also known as a cognitive map. It may
be part of a syndrome known as visuospatial dysgnosia.
is defined based on the context in which it is used (aviation, geometry,
geographical survey, sport, atmospheric pressure, and many more). As a
general definition, altitude is a distance measurement, usually in the
vertical or "up" direction, between a reference datum and a point or
object. The reference datum also often varies according to the context.
Although the term altitude is commonly used to mean the height above sea
level of a location, in geography the term elevation is often preferred
for this usage. Vertical distance measurements in the "down" direction are
commonly referred to as depth.
Which way is North ?
How to tell which way is North using the Sun
The Directions below are for the Northern Hemisphere.
In the Southern Hemisphere it's the Opposite (North is now South)
Place a 3' long stick in the ground firmly
Mark the end of the shadow from the 3' long stick with a smaller stick.
Now wait around 15 minutes.
Use another small stick to mark where the end of the shadow is now.
Lay another stick on the ground so that it touches both small sticks.
Place your left foot towards the first small stick marker.
Place your right foot towards the second small stick marker.
With your body facing the 2 small sticks used to mark the ends of the shadow you are now facing north. Your Right is east,
your left is west and behind you is south.
At 12 noon your shadow will be facing North in the Northern Hemisphere
Finding North without a compass #1
Another way using the Sun to tell Direction
If you have a digital watch with no hour & minute hand then just replicate a
watch with sticks to match the time on your digital watch.
Point the hour hand at the sun.
Half way between the hour hand and 12 noon will be do south.
(If you are in the southern Hemisphere the it would be north)
When facing north, your Right is East, your Left is West.
At Night know how to use the Stars and Moon to tell North,
but of course it's always best to carry a Compass.
The North Star is the last star in the handle of the Little
You can also find the North Star by using the Big
The outermost stars of the cup of the Big Dipper
forms a straight line that always "points" to the North Star or Polaris.
Find True North Without a Compass
Tell Time Without a Clock
Hiking and Trails Information
is the ancient science of position fixing that
enables a navigator to transition through a
without having to rely
on estimated calculations, or dead reckoning, to know their position.
Celestial navigation uses "sights," or angular measurements taken between
a celestial body (the sun, the moon, a planet or a
) and the visible
horizon. The sun
is most commonly used, but navigators can also use the
moon, a planet, Polaris, or one of 57 other navigational stars whose
coordinates are tabulated in the nautical almanac and air almanacs.
Celestial navigation is the use of angular measurements (sights) between
celestial bodies and the visible horizon to locate one's position on the
globe, on land as well as at sea. At a given time, any celestial body is
located directly over one point on the Earth's surface. The latitude and
longitude of that point is known as the celestial body’s
(GP), the location of
which can be determined from tables in the Nautical or Air Almanac for
that year. The measured angle between the celestial body and the visible
horizon is directly related to the distance between the celestial body's
GP and the observer's position. After some computations, referred to as
sight reduction, this measurement is used to plot a
line of position
(LOP) on a
navigational chart or plotting work sheet, the observer's position being
somewhere on that line. (The LOP is actually a short segment of a very
large circle on the earth which surrounds the GP of the observed celestial
body. An observer located anywhere on the circumference of this circle on
the earth, measuring the angle of the same celestial body above the
horizon at that instant of time, would observe that body to be at the same
angle above the horizon.) Sights on two celestial bodies give two such
lines on the chart, intersecting at the observer's position (actually, the
two circles would result in two points of intersection arising from sights
on two stars, but one can be discarded since it will be
far from the estimated position. Most
navigators will use sights of three to five stars, if they're available,
since that will result in only one common intersection and minimize the
chance for error. That premise is the basis for the most commonly used
method of celestial navigation, and is referred to as the
'. There are several other methods of celestial
navigation which will also provide position finding using sextant
observations, such as the noon sight, and the more archaic lunar distance
method. Joshua Slocum used the lunar distance
method during the first ever
recorded single-handed circumnavigation of the world. Unlike the
altitude-intercept method, the noon sight and lunar distance methods do
not require accurate knowledge of time. The altitude-intercept method of
celestial navigation requires that the observer know exact
Greenwich Mean Time
(GMT) at the moment of
his observation of the celestial body, to the second—since every four
seconds that the time source (commonly a chronometer or in aircraft, an
accurate "hack watch") is in error, the position will be off by
approximately one nautical mile.
Why we see the same Stars
? (star charts)
in the sky is defined by a pair of angles relative to the
celestial equator: declination (d) and right ascension (a). While d is
given in degrees (from +90° at the celestial north pole to -90° at the
south pole), a is usually given in hours (0 ... 24h). This is due to the
observation technique of star transits, which cross the field of view of
telescope eyepieces because of Earth's rotation. The observation
techniques are topics of positional astronomy and of astrogeodesy. Ideally
the two-dimensional coordinate system a, d refers to an inertial frame of
reference; the 3rd coordinate is the star distance, which is normally used
as an attribute of the individual star. Star positions are changing in
time, caused by precession and nutation – slow tilts of Earth's axis with
rates of 50 arcseconds and 2 arcseconds respectively, per year; aberration
and parallax – effects of Earth's orbit around the Sun; proper motion of
the individual stars. The effects 1 and 2 are considered by so-called mean
places of stars, contrary to their apparent places as seen from the moving
Earth. Usually the mean places refer to a special epoch, e.g. 1950.0 or
2000.0. The 3rd effect has to be handled individually. The star positions
a, d are compiled in several star catalogues of different volume and
accuracy. Absolute and very precise coordinates of 1000-3000 stars are
collected in Fundamental catalogues, starting with the FK (Berlin ~1890)
up to the modern FK6. Relative coordinates of numerous stars are collected
in catalogues like the Bonner Durchmusterung (Germany 1852-1862, 200.000
rough positions), the SAO catalogue (USA 1966, 250.000 astrometric stars)
or the Hipparcos and Tycho catalogue (110.000 and 2 million stars by space
astrometry). Space Travel
is the equatorial coordinate specifying the angle,
measured eastward along the celestial equator, from the vernal equinox to
the intersection of the hour circle that passes through an object in the
sky; usually expressed in hours and minutes and seconds; used with
declination to specify positions on the celestial sphere.
is the angular distance of a celestial body north or to
the south of the celestial equator; expressed in degrees; used with right
ascension to specify positions on the celestial sphere.
A minute of arc
, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to 1/60th of one
is often specified in
Astronomical Units (AU)--an AU is the
average distance from the Earth
to the Sun = 149,597,870 kilometers (92,955,730 miles). For objects
outside the solar system, the light year (ly) is often used. This is the
distance light travels in a year,
One light year
is equal to 63,240 AU.
is a unit of length
roughly the distance from Earth to the Sun. However, that distance varies
as Earth orbits the Sun, from a maximum (aphelion) to a minimum
(perihelion) and back again once a year. Originally conceived as the
average of Earth's aphelion and perihelion, it is now defined as exactly
149597870700 metres (about 150 million kilometres, or 93 million miles).
The astronomical unit is used primarily as a convenient
distances within the Solar System or around other stars. However, it is
also a fundamental component in the definition of another unit of
astronomical length, the parsec.
Astronomical System of Units
is a system of measurement developed for
use in astronomy
is the tracing and measurement of a series or network of
triangles in order to determine the distances and relative positions of
points spread over a territory or region, especially by measuring the
length of one side of each triangle and deducing its angles and the
length of the other two sides by observation from this baseline. In
trigonometry and geometry,
is the process of determining the location of a point by
forming triangles to it from known points.
is a method of establishing geodetic
relationships between points on the earth’s surface by simultaneous
observations of the moon, high-altitude balloons with light sources, or
artificial earth satellites from these points.
, typically made of transparent plastic or
glass, for measuring angles
. Most protractors measure angles in degrees
(°). Radian-scale protractors measure angles in radians. Most protractors
are divided into 180 equal parts. They are used for a variety of
mechanical and engineering
applications, but perhaps the most common use is in geometry lessons in
schools. Some protractors are simple half-discs. More advanced
protractors, such as the bevel protractor, have one or two swinging arms,
which can be used to help measure the angle.