Gis for healthcare Introduction

1. GIS for Healthcare
Introduction
Dr. M H B Ariyaratne
Mrs. Nadeeka Darshani
2016 March - Health Information Unit, PDHS-SP
goo.gl/nsHwD6

2. Geography
● A field of science devoted to the study of the lands, the features, the
inhabitants, and the phenomena of Earth.
● The study of places and the relationships between people and their
environments.
● Geographers explore both the physical properties of Earth's surface and
the human societies spread across it.

3. GIS
● Geographical Information System
● 1968 > "A Geographic Information System for Regional Planning"
● System of input, storage, processing, retrieval, and presentation of spatial
data
● Spatial data - data on location and shape of geographical feature

4. Global Navigation Satellite Systems
● Global navigation satellite systems
○ Operational
■ GPS (US)
■ GLONASS (Russia)
■ Galileo (EU)
○ In Development
■ BeiDou-2 (China)
● Regional navigation satellite systems
○ BeiDou-1 (China)
○ NAVIC (India)
○ QZSS (Japan)

5. GPS
● Global Positioning System
● A global navigation satellite system (GNSS)
● Owned by the United States government and operated by the United States
Air Force.
● A global navigation satellite system that provides geolocation and time
information to a GPS receiver anywhere on or near the Earth where there is
an unobstructed line of sight to four or more GPS satellites
● Does not require the user to transmit any data
● Operates independently of any telephonic or internet reception

6. Mapping in Public Health
● Olden days - Certain diseases
more common in different
locations
● 1854 - Cholera outbreak - John
Snow
● 1934-35 - Malaria Epidemic
● Extensively used in Public Health

7. Geographic Coordinate Systems
● A coordinate system used in geography
● Enables every location on Earth to be
specified by a set of numbers, letters or
symbols.
● Often one of the numbers represents a vertical
position, and two or three of the numbers
represent a horizontal position.
● Common choice of coordinates is latitude,
longitude and elevation
● Longitudes and Latitudes can be in Degrees +
Minutes + Seconds or Degrees + Minutes or

8. Projection Systems
● A systematic transformation of the latitudes
and longitudes of locations from the surface of
a sphere or an ellipsoid into locations on a plane
● Maps cannot be created without map
projections
● All map projections necessarily distort the
surface in some fashion
● Depending on the purpose of the map, some
distortions are acceptable and others are not
● Different map projections exist in order to
preserve some properties of the sphere-like
body at the expense of other properties.

9. Geodetic System
● A coordinate system and a set of reference
points
● Used to locate places on the Earth or similar
objects
● Translate positions indicated on maps (paper
or digital) to their real position on Earth
● The difference in coordinates between datums
is commonly referred to as datum shift.
● Conversion among different geographic
coordinate systems is possible (Ex. in QGIS)

10. World Geodetic System
● A standard for use in cartography, geodesy, and navigation including GPS.
● It comprises a standard coordinate system for the Earth
● Latest revision is WGS84
○ Established in 1984
○ Also known as WGS 1984, EPSG:4326
○ Default CRS in Q-GIS

11. Localised Datums
● Defined for a selected area on Earth
● Because the Earth is an imperfect ellipsoid, localised datums can give a
more accurate representation of the area of coverage than WGS 84
● Example
○ Kandawala / Sri Lanka Grid
■ EPSG:5234
■ Projected coordinate system
■ Based on Kandawala Datum
○ Kandawala
■ Geodetic coordinate system
■ EPSG:4244

12. ArcGIS
● Most popular GIS software
● Different Editions - ArcReader, ArcGID Desktop Basic, etc
● Proprietary commercial software
● Developed and maintains shape file format
● Desktop version runs only in Windows Platforms

13. Q-GIS
● Desktop geographic information system (GIS) application
● Supports viewing, editing, and analysis of geospatial data
● Cross-platform
● Free and open-source

14. Thank you