Interpolering

Question 1

What is interpolation

Answer 1

This is a method used to estimate unknown value for a specific location based on known values from nearby points .

Question 2

True or false : interpolation relies on the assumption that things that are close together tend to have similar characteristics

Answer 2

True

Question 3

How can you get a regression line

Answer 3

By using python .
Manually you can put the regression line close to all points to represent actual data.

Question 4

What is y= ax + b ?

Answer 4

This is a formulae used to represent a regression line.

Question 5

When is interpolation used ?

Answer 5

Estimating data in places where no observations were made .
Transformation of one raster to another grid
To draw contour lines between measurements

Question 6

True or false: nearby places are more similar than distant places ( the most important assumption in interpolation)

Answer 6

True

Question 7

True or false: when interpolating always follow the first rule of geography which is taking the closest measurement points .

Answer 7

True

Question 8

There are three common interpolation methods name them.

Answer 8

IDW; inverse distance weighting
Kriging
Trend surface

Question 9

Define Inverse distance weighting

Answer 9

This estimates unknown values of a specified location by averaging the known values of nearby points giving more weight to points that are closer to the location of interest.
Output is raster because you have continuous surface as an output

Question 10

Define kriging

Answer 10

An advanced geostatistical method that generates an estimated surface using a scattered set of points with known values. It considers both the distance between points and the spatial correlation .

Question 11

There ar different spatial sampling schemes , what are they ?

Answer 11

Random sampling
Systematic sampling
Clustered sampling

Refer to post it for pictorial rep.

Question 12

How are sampling methods chosen

Answer 12

They are chosen based on scientific (known spatial distribution of Values)and practical factors (time, budget, routes )

Question 13

What are the results of interpolation dependent on .

Answer 13

Sampling method
Interpolation method
Spatial characteristics of the sampled variable.

Question 14

What is the downside about IDW

Answer 14

You cannot calculate peaks if you do not have a resolution data which achieved with more points