Senior Software Developer at Openapp
Work primarily on GIS.
(I develop maps to solve problems)
A visual representation of an area showing features such as cities, rivers, roads or mountains.
A Scale tells us distance.
Scales are expressed as ratios.
A 1:100000 scale map means that 1cm on the map is worth one 1km on the ground.
Coordinates tell us where (location)
They allow us to represent a location accurately.
There are many different ways to write the same coordinates.
One method you may be familiar with is a National Grid.
N 444 557 - OSI Grid Reference
244464 E, 255704 N - Irish National Grid
644406 E, 755726 N - Irish Transverse Mercator
53.550° N, 7.33° W - WGS84 (Decimal Lat/Lon)
53° 32' 58.5"N, 07° 19' 47.7"W - WGS84 (Deg, Min, Sec)
53° 32.9747' N, 7° 19.795' W - WGS84 (Deg, Decimal Min)
Stands for Global Positioning System
Consists of a network of satellites in orbit.
Allows anyone with a GPS receiver to find their location.
Navigation for People/Cars/Boats/Aircraft etc
Surveying, Mapping and Construction
Security and Cargo
Mobile Phone networks
Search and Rescue
US began the GPS project in 1973 to replace older systems.
Navstar (Navigation System Using Timing and Ranging)
Korean Air Lines Flight 007 was shot down in 1983 after straying into the USSR.
Ronald Reagan issued a directive making GPS freely available for civilian use.
Fully Operational in April 1995
24 satellites in orbit, at least 4 in view regardless of location.
Each equipped with a very accurate atomic clock.
Broadcasts current time and position.
GLONASS - Russian GLObal NAvigation Satellite System
IRNSS - Indian Regional Navigation Satellite System
COMPASS/BeiDou - Chinese Navigation Satellite System
Galileo/GNSS - European Union (Active in 2020)
You are driving home at 100km/hr
Home is two hours away.
Assuming your speed is constant, how far do you have to travel in km?
distance = speed x time
distance = 100km/hr x 2 hours
200km = 100km/hr x 2 hours
Weather conditions and line of sight
Number of Satellites in view