Transcript GPS: Global Positioning System

GPS
GIS
GIS in Campbell
River
GPS
GIS
GIS in Campbell
River
GPS: Global Positioning
System

Originally designed for use by the military
 It is a satellite-based, radio navigation system
giving accuracies of around 25 meters, anywhere
on earth
How receivers use satellites

Receivers are able to determine the distance to a
satellite
 Need at minimum of four satellites to determine
your location in 3D (there are four unknows:
latitude; longitude, height and receiver clock
error)
Two satellites and
you know the
distance to each one
Three satellites with
three known distances
Errors inherent to GPS

Positional error is due to:
– the individual GPS pseudorange
– dilution of precision effect of the satellite geometry
Errors in GPS:
Pseudorange
Differencing to correct for pseudorange
Errors in GPS: Dilution of precision

Due to the position of the satellites
Good geometry
Bad geometry
GPS
GIS
GIS in Campbell
River
GIS: Geographic Information
System

GIS is a computer system capable of
assembling, storing, manipulating, and
displaying geographically referenced
information
 Relate information from different sources as
long as the location of variables are known
(aerial photographs with water sampling
information)
Data capture

Data available in digital form, in a form the
computer can recognize
 If the data to be used are not already in digital
form, various techniques can capture the
information. Maps can be digitized, or handtraced with at computer mouse, to collect the
coordinates of features. Electronic scanning
devices will also convert map lines and points to
digits
 Data can be collected with a GPS unit
Data collection methodology

SHIM: Sensitive Habitat Inventory and
Mapping
– Collects the centerline of the stream (points or
dynamic line) while locating habitat features and
features affecting fish distribution and stream health
– Examples of features:
Bridges, Culverts, Bank Erosion, Storm Drain
Enhancement Sites, Spawning Habitat, Wetlands
Integration of Data

Various programs to integrate the data
 Process of adding layers
 Ability to link to databases
Integration of Data
Final Product
GPS
GIS
GIS in Campbell
River
GIS in Campbell River
Streams with
SHIM Data in
the Campbell
River Area and
on Quadra Island
GIS in Campbell River
 Obtain
GIS layers
 Review
the SHIM data and conduct
Quality Assurance – Quality Control
 Production
of the Community Watershed
Atlas and to get data included into the
Sensitive Habitat Atlas