GPS Assignment

GPS Certification Program

Part A:

1. UTM stands for universal transverse mercator geographic coordinate system.What you often see on poster-size maps of the world is an equatorial mercator projection that has relatively little distortion along the equator, but quite a bit of distortion toward the poles. By slightly changing the orientation of the cylinder onto which the map is projected, successive swaths of relatively undistored regions can be created. This is exactly what the UTM system does. Each of these swaths is called a UTM zone and is six degrees of longitude wide. The first zone begins at the International Date Line (180°, using the geographic coordinate system). The zones are numbered from west to east, so zone 2 begins at 174°W and extends to 168°W. The last zone (zone 60) begins at 174°E and extends to the International Date Line. The zones are then further subdivided into an eastern and western half by drawing a line, representing a transverse mercator projection, down the middle of the zone. Any point can then be described by its distance east of the origin (its ‘easting’ value). Distances and locations in the UTM system are measured in meters. Each UTM zone has its own origin for east-west measurements. In the northern hemisphere, the origin is the equator and all distances north (or ‘northings’) are measured from the equator.

2. Latitude is a point on the earths surface thats is angled between the equatorial plane of a line that passes through that point normal to the surface of refernece ellipsoid which approximates the shape of the earth. Lines joining points of the same latitude trace circles on the surface of the Earth called parallels, as they are parallel to the equator and to each other. The north pole is 90° N; the south pole is 90° S. The 0° parallel of latitude is designated the equator, the fundamental plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres. The longitude of a point on the earths surface is the angle east or west from a reference meridian to another meridian passes through that point. All meridians are halves of great ellipses (often improperly called great circles), which converge at the north and south poles.
There are three different formats to determining the longituted and latitidue

1. degrees, minutes, seconds (for example, 076 30' 45"); 2. degrees, minutes, decimal (076 30.75'); or
3. decimal (degrees) (076.5125)

3.
Using Land Features: Lay the map on the ground or hold it horizontally. Rotate the map until recognized features on the ground roughly align with those on the map.
Using a Compass:
1. Identify your declination from your map. If your declination is West of true north, subtract the declination from 360 degrees. If your declination is East of true north
2. Set the compass at the correct declination bearing so that you compensate for declination.
3. Place your compass on the map so that the edge of the baseplate lies is parallel to the east or west edge of the map with the direction of travel arrow toward the north edge of the map.
4. Holding the compass on the map, rotate the map with the compass until the north end of the magnetic needle points to the N on the compass housing (i.e. the red north end of the magnetic needle and the orienting arrow align). This is often referred to as "boxing the needle" since the magnetic needle is inside the "box" formed by the orienting arrow. The map is now oriented with respect to magnetic north. This means that the compass needle direction north is the same as true north on the map. You can also place the compass on the map so that the edge of the baseplate lies along the magnetic north indicator line on the map legend at the bottom and rotate the map as described above. This may give you a more accurate orientation for your map.

4. Global positioning system is a space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver.

Part B:

The gps was originally designed for military and intelligence applications at the height of the cold war back in the 1960’s. The inspiration came from the launch of the Soviet spacecraft Sputnik, in 1957. The global positioning system is a network of satellites that orbit the earth at fixed points above the planet and beam down signals to anyone who has a gps receiver. Transit was the first satellite system launched by the USA and tested by the US navy in 1960. Five satellies orbiting the earth allowed ships to fix their position on the seas once every hour. In 1967 Transit was succeeded by the Timation satellite. It demonstrated that highly accurate atomic clocks could be opperated in space. The Gps developed quickly for military purposes, with a total of 11 “block” satellites being launched between 1978 and 1985. It wasn’t until the USSR shot down the Korean passenger jet in 1983 that the Reagan Administration in the US opened up the GPS for civilian applications so that aircraft, shipping and transport the world over could fix their positions and avoid straying into forgein territory. Upgrading the GPS was delayed by NASA space shuttle SS challenger diaster in 1986. It was not until 1989 that the first block II satellites were launched.