Lec 6: Geographic Information Science and Geographic Reference Systems

A SET of: San Francisco Images

Announcements

Next Week: Mid Term Exam

A (new) date has been set for the final exam:

Monday April 21st 2 pm.

Readings: nil

Questions?

The Ombudsman meeting will take place today

How are the Labs and Assignments going?

I owe you an explanation....

The Readings for Today’s Lecture were:

Ch. 11 Locational Reference Systems

Ch. 19: GIS and Map Analysis Software

Questions/Comments on the Readings?

Today’s Lecture

Mock Mid Term

Geographic Information Science

Geographic Reference Systems

Mock Mid Term

Scope of the exam: “Mostly Readings”

Eight assigned Readings Chapters and associated Lecture units:

Intro, Chapters 1, 2, 3, 4, 5, 11, 19, 24

Assignments No. 1 and 2

To better prepare we will look at a Mock Mid-Term as an example of:

the format

and content of the actual test.

Working through the Mock Mid-Term....

Geographic Information Science

We begin with a series of Examples for types of problems that can be solved with GIS:

Cartometrics

The Nearest Airport Problem

MFWorks files:

SW—Ontario—Cities

AlternativeNearestAirport

Address Matching

Two Spatial/Object Query Types:

Where is Something?

eg. A Settlement at night

What is Somewhere?

eg. The elevation along a night flight path

Route Finding

Shortest Route to Washington DC

Statistical Mapping

Urban Residential Area density (for flight corridors in/out of the city’s airport)

Terrain (surface) Analysis - 2 main sub-types:

Surface Profiles

Flight path surface profile (incl. derivatives)

Example from the text (Fig. 19.6)

Our own Examples: SunStang project (MFWorks files)

Slope and Gradient

Examples: Campbell Hills DEM derivatives — Landforms (MFWorks files)

such as: slope, gradient, inflection, drainage

Spatial Optimization

Spatial Multi-Criteria Decision Making

The student house hunt problem

Spatial Decision Support Systems (SDSS)

Resident Expert in the Geog. Dept.: Prof. Jacek Malczewski

- 2 main sub-types:

Route Selection

eg. Airline network selection and scheduling

Site Selection

Airport site selection discussed in text

Redistricting

Example: Sarnia-Clearwater fire station districts

GIS- a few introductory comments (by Pazner)

What essentially is GIS?

GIS can be represented by a Venn Diagram that has Automated Cartography, Spatial Analysis, and Geographic Database circles

A further reduction can be often achieved by simply invoking the 2 words: Modern Cartography.

And for the layperson — Modern Map Making and Use is not a bad way to characterize or look at GIS.

GIS paradigms are abundant:

• applied/user paradigm: possibly the broadest category. Think of a constellation of interdisciplinary applications, replete with sub-views of what GIS is.

• analytical cartography paradigm: computational, quantitative, scientific, knowledge representation issues...

• technological: GIS as ‘skill’, keywords: ‘GIS analyst’, college accreditation, ‘technicians’

• software development: computer science oriented (someone has to develop the thing)

What is the student and others’ excitement all about?

• from descriptive to derivative: the ability to progressively generate new information (Michael Gould, GIS World Sourcebook, 1996)

— and the ability to make implicit spatial relations explicit

e.g. multiple distances

from internal to external: from passive cognition to active manipulation—

to think spatially and to be able to actually do something about it

Modeling

Value-Free Measures

eg. land “trafficability”

Value-Ladden Measures

GPS-Driven Applications

Navigation

Precision Farming

Navigation

Fugawi

Precision Farming

Break

Geographic Reference Systems

Key concepts:

spatial reference system

two main kinds of frames of reference

Concrete Frames of Reference

Place Names

Question: How PC is our textbook on this subject?...

cf.

“Whorehouse Meadows”

Bullshit Springs (as opposed to Cowshit Corner, Maine)

Place names in the Adirondack Mountains

Example: Artistic Drawing (Jpeg)

How did Nippletop Mountain earn its name?

(note: these are not the Grand Tetons, WY)

Panoramic View (Jpeg)

Abstract Frames of reference

Point Locating Systems

Geographic Grid

Plane Grids

Zone Locating Systems

Geographic Grid (or graticule)

Longitude lines (meridians, 360 degrees)

Latitude lines (parallels, 180 degrees)

Question: Precision and possible accuracy up to?

Answer: Within 100ft!

Fig 11.1: Arc units aren’t constant

Arc units aren’t constant

1 degree of latitude averages 69 miles but varies slightly between the Equator and the North Pole (Why?)

1 degree of longitude varies from about 69 miles at the Equator and 0 (!) the North Pole (Why?)

Fig. 11.2

Table E6

Table E7

Latitude and Longitude both vary (differently) and can’t be measured without instruments.

“GPS to the Rescue”

Fig. 11.3

Plane Coordinates

move away from Spherical Coordinates and their associated problems

(Woman on chair) grids on 3D orbs....

ButtIsItRaster? file (Jpeg)

The fact that plane coordinates represent a projection

to a flat 2D plane

is not too much of a problem for small areas

The major issue is the choice of an Origin:

arbitrary

tied to the ground - a terrestrial reference system

Arbitrary

Local Grid

Cartesian Coordinate System

Fig 11.4: Cartesian Coordinate System

State Plane Coordinates (UPC)

...now largely obsolete

Universal Transverse Mercator (UTM) Grid

Fig 11.7

Fig 11.8

Fig 11.9

Important concept:

False Easting

False Northing

Universal Polar Stereographic (UPS)

Why needed?

Coordinate Determination and Plotting

techniques discussed in text

Use of a Roamer

Easting and Northing:

Go “Right-Up” fromLower Left corner

Zone Locating Systems

Zone (rather than Point) coordinates

Arbitrary Local Zones

local grid zones (city map)

Proprietary Grid

Map Publishers

eg. Thomas Brothers Maps

DeLorme

Amateur Radio Operators (HAM) hierarchic “Maidenhead” global reference system

US Military Grid

‘til next week!

And now, a problem in solemn memory of those who perished on Swissair Flight 111: A plane is approximately over Woodstock and the pilot wishes to know how much further-or-closer London Airport is to the following six nearby airfields: Stratford, Kitchener, Brantford, Tilsonburg, St Thomas, and Exeter (east of Grand Bend).