Lab Notes

Question 1

Short Integer

Answer 1

2 byte Integers (-32768 to 32768)

Question 2

Long integer

Answer 2

4 byte integer (-2bil to 2bil)

Question 3

Float

Answer 3

Single precision floating point number - -3.4E38 to 1.2E38

Can be decimals

Question 4

Double

Answer 4

Double precision floating point number - -2.2E308 to 1.8 E308
Can also be decimals

Question 5

Joining data

Answer 5

Right click data in list - add join, select both fields to be joined
Name output field

This allowed us to join census data to county shapefiles bc they shared the same FIPS code

We also used this to join gas leaks to zip codes after assigning zip codes to each gas leak point - didn’t need a an attribute to join based on because they were joined based on spatial data

Question 6

Calculating slope

Answer 6

Use slope tool - enter a raster
We used this to get slope with the raster that had elevation (the DEM)

Then RECLASSIFIED the raster so the suitable slopes had a value of 1 and the not suitable slopes had a value of 0

Question 7

Reclassify

Answer 7

Changes the value of a entries in a raster either to perform a conversion, or select values that you need (by converting them to 0 and 1)

Question 8

Map algebra

Answer 8

With raster inputs that have been reclassified to reflect which areas are desired, map algebra allows you to create a statement that finds areas that fit that requirement in an intersection of multiple inputs

Question 9

Geocoding

Answer 9

right click on file with addresses and select geocode addresses

Question 10

Spatial Join

Answer 10

We used to determine zip code of gas leaks
Target Features - the information the join is based on
Join Features - the feature whose information will be transferred to the target

The gas leaks was the target feature and received the information of the zip code based on its spatial location

Question 11

Count

Answer 11

To count number of gas leaks in zip code, we added a field named count, then used the FIELD CALCULATOR to assign a value of 1 to each one

Question 12

Guidelines for Control Points (for georeferencing)

Answer 12

spaced out over image
distinct static geographic features
minimum of 3 points but not much more
zoom in when selecting
first click on location in UNREFERENCED layer then on the referenced layer

Question 13

Setting up georeferencing

Answer 13

create a bookmark where the image should end up, zoom to the layer that contains the image to be georeferenced.

Then imagery -> georeference

Question 14

Digitizing Features (Creating your own shapefile)

Answer 14

In right toolbar, under catalog, untwirl current project database and right click, select “new shapefile,”

drag the shapefile onto the map

in edit toolbar -> create features, then drawing tools become available

right click on shapefile and open attribute table to edit names of shapes, etc