Geogrpahic Data Flashcards Preview

Geography176B > Geogrpahic Data > Flashcards

Flashcards in Geogrpahic Data Deck (19)
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1
Q

Spatial dependency

A

The manifestation of toblers first law of geography, by which variance increases with distance in characteristic ways

2
Q

What is the first step before analysis?

A

We need to measure the expected degree of dependency amount nearby observations

3
Q

What is spatial heterogeneity?

A

Tendency of spatial data to exhibit spatial non-stationarity I.e the change of local statistical parameters with location makes identifying representative samples difficult

4
Q

Types of stratified sampling

A

Stratified sampling - sampling in regular grid pattern
Stratified random sampling - sampling randomly within gridded space
Stratified sampling with random variation in grid spacing

5
Q

Other types of sampling

A

Clustered sampling - sampling only in certain grid spaces
Transect samplibn - sampling multiple points along a transect
Contour sampling - sampling at multiple points along a contour

6
Q

What May effect simple random sampling

A

Strategy at be affected by outliers

7
Q

What may affect stratified random sampling ?

A

Strategy may be effected by periodicity

8
Q

What are the three types of distance decay

A

Linear distance decay
Negative power distance decay
Negative exponential distance decay

9
Q

What is spatial resolution

A

The smallest feature that can be detected I.e. the pixel size

10
Q

Temporal resolution

A

Smallest time interval between a repeated observation

11
Q

Spectral resolution

A

Number, position and width of spectral bands

12
Q

Radiometric resolution

A

Small distinguishable differences in radiation and magnitude

13
Q

What is the difference between autocorrelation and smcross correlation

A

In contrast to autocorrelation, cross correlation compares different variables

14
Q

What spatial statistic technique

A

Moran’s I

15
Q

How do we interpolate for objects

A

Use local neighbourhood data to estimate a value at an I sampled location (I.e closest number if point nys or within a given search radius)

Can also use the entire dataset toto estimate a value at an unsnapped location

16
Q

What is the difference between interpolation vs extrapolation

A

Interpolated values are the estimated point is within the range of the data

Extrapolation is when the estimated point is outside the range of the data

17
Q

What is isotropicity

A

Uniform change in all directions (assumed in distance decay)

18
Q

What is a c

Concatenated key

A

A table with a FIPS code

19
Q

What is a primary key?

A

A unique identifier for every row in a table