Methods to find your coordinates on globe

A coordinate system that helps us finds the location on the Earth by using set of numbers and letters. Among these coordinates one of the number represents vertical position and other two numbers represent horizontal position. Commonly they are called latitude, longitude and elevation.

Finding Your Coordinates

Longitude

Longitude is that geographic coordinates that specifies the east-west position of a point on the Earth’s surface. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lamda. If we have points with the same longitude it means the points lies in line running from North Pole to the South Pole.

Prime Meridian is a point that passes through Greenwich England, and showing the position of zero longitude using this as a reference the longitude of other places is measured as an angle east or west from prime Meridian, ranging from zero degree at prime meridian to +180 degrees eastward and -180 degrees westward.

latitude

Latitude is a geographic coordinate that specifies the north-south position of a point on the earth’s surface. Latitude is an angle which ranges from zero degrees at the Equator to 90 degrees at the North and South poles.
Latitude is used together with longitude to specify the precise location of features on the surface of the earth.

Altitude

Coordinates on earth surface

Altitude or height or Elevation is defined generally as a distance measured in vertical or up direction, between a reference datum and a point or object. The reference datum is usually the datum sea level.
Methods to find out your location coordinates
Now days with the advancement in technology there are various ways with the help of which we can find out the coordinates of our location on the earth surface.

Using GPS – Global Positioning System

The most common and the most accurate is the GPS, GPS stands for Global Positioning System and as its name implies, it is used to tell you your exact position on the globe (world's surface) to an accuracy of about 5 meters.
 

People regularly use GPS technology in everyday life and in some cases they may be unaware that it is a modified GPS unit. A great example of this is satellite navigation systems in cars, these use GPS technology along with map information to give you road directions. SatNavs and GPS units utilize a network of satellites. These satellites transmit precise microwave signals to the GPS unit, which enables a GPS receiver to determine its’ location; speed and direction. A GPS receiver calculates its position by measuring the distance between itself and three or more GPS satellites using a method called triangulation. In triangulation, a microwave signal is sent out from three or more satellites to the GPS receiver, the length of time it takes to receive a single signal relates to a distance measurement. These measurements allow the GPS unit to Make an accurate approximation of its location.
 

Finding your Sample Site Coordinate using GPS

Using Global Positioning System (GPS)

You could simply write down the location information that your receiver calculates and/or
you can store the waypoint in the receiver. You will need to save your sample site location
as a waypoint; this is useful as you can later use this point as a navigation guide and it also acts as a digital copy of your coordinate, which can be, used alternative non‐paper back up.

1)     In order to save your location you need to first make sure you are standing at your
sample site. Next navigate to the ‘map’ screen using the ‘page’ button.

2)    In the top right hand side of this screen there should be a box titled ‘accuracy’
you need to write the ‘accuracy’ value down on your data sheet (value in meters). THIIS VALUE MUST BE BELOW 5 METRES.

3)    Once you have an accuracy value at or below 5 meters you can make an accurate
waypoint. Press and hold the ‘Enter’ button on the map screen until a ‘waypoint’ screen appears. Once in this screen you can save and edit your waypoint coordinate information.

4)     First, before you edit your waypoint, you must write the location value onto your
data sheet. This value must be given in decimal degrees (will appear on you screen
as a number followed by a ‘°’ symbol).

5)     In the first large box you can edit the name of your waypoint  the name of the waypoint
is often set as a number by default,  you should change this to a name that is easily distinguishable as your sample site (for example use GLWW). Using the ‘rocker’ key highlight this box and click ‘Enter’, you can now use the ‘rocker’ to select letters using a pop up keypad, click ‘ok’ once you have selected all your desired letters. You can then repeat this same method in the comment box.

6)     After you have edited your waypoint data select ‘ok’ using the ‘rocker’ key and
press ‘enter’. This will save the waypoint coordinates into the internal memory of
the GPS unit.
 

Using Google earth

When you have the street address or the zip code you can easily calculate the latitude, longitude and altitude with the help of google maps or google earth.
1.    Open the google earth software – free to download from the google and then enter your location information in the search box
2.    Zoom in the Google earth as much as possible until you find the location exactly as required.
 
3.    Move the mouse cursor over the desired location as shown here in the picture with A.
4.    Then from the status bar read the coordinates of the desired location
 

The coordinates of the admin block as shown here is 33045’57.07’’ N and 72049’31.18’’ E and elevation is 1638 ft.

The coordinates of the Civil Department as shown here is;
330 46’ 00.13’’ N and 720 49’ 30.73’’ E and elevation is 1644 ft.
My location approx. on the day the assignment was given has coordinates of

330 46’00.66’’ N 720 49’ 29.68’’ E and elevation of 1646 ft from ground and as I was on the first floor it could be approximately 1646 ft + 11 ft = 1657 ft.