Fall 2009 Lab Exercise #1 Answer Key
ArcMap, ArcCatalog, ArcToolbox
2.What is the difference between surfaces and features? (Which is vector and which is raster?What are their properties?
Features: These are point, line, or polygon representations of entities you find on the surface of the earth. They attempt to express graphically mimic the shape of the real world entities that they represent. (vector or raster)
Surfaces: These are measured values, sampled in regular intervals along a grid of usually square cells.They are good for continuously changing data such as elevation, rainfall, and wind speed. (vector or raster)
3.On a State map, what feature class type (point, line, polygon) would you use for each of the following layers?Also list three possible attribute types for each layer.
LayerType Attribute Attribute Attribute
a. State Highways line, surface*, highway #*, highway name*
b. Major Reservoirs_polygon, name, surface, area, depth
c. Historical Sites point, name, year, type of site
* Example attribute types
4.Describe two possible applications (uses) of GIS.List some feature classes (layers) might be a part of that application.
a. Answers will vary
Layers -________________________________________________________________
________________________________________________________________________
b. Answers will vary
Layers - ________________________________________________________________
________________________________________________________________________
1. Investigate the contents of this folder (use the Content and Preview tabs).
List the files below:
NameExtension (.???)Type*What’s in this layer?
a. Faults.lyr, Layer, Faultline graphics for Faults.shp
b. Faults.shp, Shapefile (line), Faultline features and attributes
c. Freeways.shp, Shapefile (line), Freeway features and attributes
d. Lab1.mxd, Map Document, All the layers and data for this map
e. Mosquito.shp, Shapefile (point), Mosquito sites features and attributes
f. Oil Pipelines.lyr, Layer, Pipeline graphics for ums_pipelije.shp
g. ums_pipelines.shp, Shapefile (line), Oil Pipeline features and attributes
h. Ventura City Streets.lyr, Layer, Street graphic for VTCITSTR.shp
i. ventura_secopy.tif, Raster Image, Image of Ventura
j. VTBLKGRP.shp, Shapefile (polygon), Ventura Census Block Group features/attrib.
k. VTCITIES.shp, Shapefile (polygon), Ventura City influence areas features/attrib.
l. VTCITSTR.shp, Shapefile (line), Ventura streets features and attributes
m. vtHospitals.shp, Shapefile (point), Ventura Hospital features and attributes
n. vtHydro.shp, Shapefile (point), Ventura stream features and attributes
*Pick one of these (shapefile/point, shapefile/line, shapefile/polygon, coverage, CAD, layer file, map document, dbase table, raster dataset, raster airphoto, personal geodatabase.)
Pick one layer to convert to thumbnail. View it in the Content mode of ArcCatalog..
2.Which layer did you pick?Answers Vary
Use the ArcMap button in ArcCatalog to start ArcMap.Open the Map Document, Lab1.mxd, found in your directory under Lab1Data. Zoom into the mainland portion of Ventura County (upper portion). Bookmark this view of the data (call it Ventura Main land).
(Hint: If there is a red ! before the name of a layer, you will need to help the program re-connect to the layer. Double-click the layer name, choose Source, then click on Set Data Source and help the program find the data set.Note that some of the layer files (.lyr) have modified names which will not be quite the same as their source data set.)
3.Which two layers become visible?
Oil Pipelines, Faults
4.Before you can view the city streets, you will need to turn on that layer.How do you turn on a layer in the table of contents? By clicking on the “check” box to the left of the layer name.
5.What color is the check box for the Ventura City Streets layer?What does it mean?
Grey.It means that this layer does not display at this map scale.Zoom in to see it.
Zoom in again to the area identified as Ventura City zone of influence.
(Hint:sometimes you can use Zoom to Layer in the layer Context Menu. Try zooming to the City Streets layer and using the magnifying glass to see the roads.)
Keep zooming until the Streets layer appears.
6.At what scale do the City Streets appear? 1:150,000.
Save this view of the data as a bookmark titled Ventura City Zone.
Zoom in once again, this time to the downtown/midtown portion of Ventura City.
Work with the layer identified in question 5. Open this layer‘s theme table and list the attributes.
7.FID, SHAPE, NAME, Cnt NAME
Modify the size of the table columns in the attribute table. Also go into layer properties to hide the count layer and rename (alias) the Name field into something bit more descriptive.
8.What did you call the NAME field? Answers will vary.
Now sort that attribute field (descending order!)
9.What is the first feature listed? Ventura Fault
In the table select that first feature (select the first row.) Minimize the table and in the Table of Contents, right click this layer and go to selection.Do the Zoom to Selected option.
10.Where is this feature located? Along Poli downtown and Loma Vista up toward the college.
Zoom back out to prior view by either using the “Go to previous extent” button or your Bookmark “Ventura City Zone”.
11.Use the select features tool and click on a different one of these features on map.
Give the name of that feature in the table (click on selected) Answers will vary
[SAVE your map Document.Called it Lab1.mxd (if you have multiple versions, you can label them Lab1a, Lab1b, ….)]
III.Exploring the Interface and Data
1.What are the four ways to add data to a Data Frame in ArcMap?
a.Add data button on the button bar
b.Right click a Map frame and pick Add Data (same button graphic)
c.File Menu: Add Data (same button graphic)
d.Drag layers from ArcCatalog into ArcMap
Add the rest of the layers (but not the Ventura_secopy.tif) to the Map Frame.
Use layer (right-click) Properties to rename each of the layers (e.g., Vtblkgrp = Census Block Groups, Hydro = Streams, vthospitals = Hospitals, vtcitstr = City Streets, vtcities = Cities).
Use the Symbolization tools to improve the look of each feature class and the map as a whole.
2.List the changes made to each feature class: (Answers will vary)
a.City Streets - _____________________________________________________________
b.Hydro -__________________________________________________________________
c.Freeway - ________________________________________________________________
d.Block Group - ____________________________________________________________
e.Cities - __________________________________________________________________
f.Hospitals - _______________________________________________________________
g.Mosquitoes - _____________________________________________________________
Ask the instructor to review you symbolization choices.
3.What suggestions, if any, did the instructor provide:
Answers will vary
[SAVE your map Document.]
IV.Raster data and Airphotos.
Activate the Ventura Airphoto Data Frame and use the zoom and pan tools to explore.Also open the table and the layer properties to observe the difference between raster and vector (feature class layers).
1. What differences did you notice?
Zoom in on image and see individual pixels, limited data attached.Values for every spot.
Drag the Ventura SE DOQQ (South East Digital Orthophoto Quarter Quadrangle) layer from the Ventura Airphoto Data Frame into the Ventura Layers Data Frame. Zoom to the Ventura SE DOQQ layer.
2. Why do you think that this airphoto is in a different data frame than the other layers?
Projections do not match.
Add the VenturaPhoto raster layer to the Ventura Layers data frame. [Used Georeference tools!]
3) What is different about this image?
It has been georeferenced to fit the other layers. The transformation created some black areas.
[SAVE your map Document.]