Department

GeographyCourse Code

GEOG 222.3Professor

XulinStudy Guide

MidtermThis

**preview**shows half of the first page. to view the full**2 pages of the document.**Midterm review !

Lecture 1 - 6, 50 multiple choice !

Geometric - the integration of data, measurement, storage, no analysis!

GIS - computer based data storage, you need to have software, hardware, geo data (spatially

related) !

Spatial data - !

Earth based or spatial based !

-Latitude is parallels, start from 0 at the equator and go to the northern or southern

hemisphere (90). Parallel to one another they never cross !

-Longitude is meridians. Prime meridian is only at one location, they go east and west, 180

degrees. They are not parallel to one another they all converge !

-Degree, minute, second or unit is in degrees !

-1 degree = 111km !

The shortest distance on earth always goes through the greater circle, all meridians are great

circles !

The seasons are caused by the tilt and revolution of the earth !

-Each hour 15 degrees have passed !

-The rotation causes the equator bulge, this is why the equator is bigger then the poles!

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Datum - the reference point or surface which measurements are made !

Geoid - hypothetical surface of the earth !

What is the datum that google earth uses - WS84 !

Projection - to convert or project the 3 dimensional earth to the ﬂat map !

3 major types of projection: or you can do it mathematically !

-planar !

-cronic!

-cylinderical !

you will distort the features no matter what projection you use, no projection can preserve all

the object correctly !

UTM - cylindrical projection, each zone is 6 degrees starting from 180 degrees west, every

degrees you move is 6 degrees !

central meridian - is to deﬁne where the central line is for each UTM zone !

#- unit is meter !

Georeferencing!

Reprojection - if you have the same projection but datum diﬀerent you have to do the

reprojection. !

#- location: accurately assigned to the same places on the projection!

#- control point: same location to both properties with the accurate coordinates, you

have to link them together. Control points have to be easy to identify !

1st order - 3 points!

2nd order - 6 points !

3rd order - 10 points!

Resampling !

-nearest neighbour!

-cubic !

-bilinear !

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