Monday, April 28, 2008

Module 9 spatial analyst

This was a difficult one for me. I learned that spatial analyst works really well with raster data to show and analyze data sets. You can create hillshades, slopes, and wieght the importants of the data that you are looking at to calculate new information

It's an awesome tool

Module 9

Wednesday, April 23, 2008

Module 10 Hillshade

Module 10 Slope

Module 10 Aspect

Using the spatial analyst add on, I took a DEM (Digital Elevation Model) of Haywood County and I added the aspect, or direction of the slope to the model. I simplified the slope in this case to North and south slopes to make it a little bit easier to read.

Module 10 Aspect

Practice Quiz 2

I could have taken out the parcel layer on the locater map, but I liked the variation in color, so I kept it. I think it would look good on a blotter.

Practice Quiz 2




This was a lot of fun, very basic clipping and map making

Wednesday, April 2, 2008

Buffers

Buffers: Buffers can be drawn at a constant distance around every feature or at a distance that varies according to attribute values. If features are close together, their buffers may overlap. You can preserve the overlaps or remove them.

Note: When using the Dissolve ALL Function with a buffer. Buffers created with the dissolve All option form a single feature called a multi part polygon. AKA the attributes go to the standard 4 objectid, shape, distance, shape length

Overlay

OverLay: When you are interested in combining data sets that overlap, overlaying is the key. You can overlay by intersecting, which preserves the area that is common to both data sets. You can also use a union that preserves everything in both areas

Chapter 11 D

To Create a New Layer

To Create a New Layer: (you could go to selection menu –Set Selectable Layers, then on the Tools toolbar click the icon to ‘Select Features.’ And click on the one you want, then right click on the layer Selection- create layer from selected features.) TADA

Clipping

Clipping: Clipping trims features in one layer at the boundaries of features in another layer. This lets you work with layers that have a common spatial extent, making it easier to navigate a map.
To Clip a spatial attribute based within a layer you must select that attribute. I first created a new layer.
To Create a New Layer: (you could go to selection menu –Set Selectable Layers, then on the Tools toolbar click the icon to ‘Select Features.’ And click on the one you want, then right click on the layer Selection- create layer from selected features.) TADA
Then go to Arc Toolbox - Extract –Clip – Remember you are Clipping one layer based on another, the input is the layer that will be changed based on the output layer TADA

Chapter 11C



TADA These are my two appended layers

Chapter 11B

Dissolve

Dissolve: A dissolve creates a new data set where features in an input table that have the same value for a specified attribute become a specified feature.
Go to: Arc Toolbox – Generalization – Dissolve – Input Features (the input layer to Dissolve) Then select the attribute you would like to aggregate

Chapter 11A




Using a dissolve I combined data based on similar attributes

Module 6 Part Duo



I thought this moment would never come. It's amazing how much time goes into making the data. It takes a special person.

Module 6 Georeferencing and snapping

Snapping (here we are making a vector layer of trail data)
Are you still with me? Ok, so snapping is a great way to georeference. So, you have your known and unknown data, right? Using the editing tool bar click the drop down to ‘start editing’note: you can only edit one data frame so if given the choice click on the one you want to edit. Using the same drop down set your ‘snapping,’ click on what you want to snap, in our case it is roads and trails. Now you want to use the edit tool to (Task) create a new feature in this case, and here we are tracing along the lines of the trails- The goal here is to make a vector layer of trail data. You can double click when you're finished and the feature will highlight. Then you can go into the attribute table and add data.
Trace tool Will allow you to trace along a feature that is highlighted, exactly copying it
How to highlight a feature click on it with your edit tool

Module 6 Part 2 Georeferencing

Georeferencing Part 2
What kind of coordinate system, what is the map projection, what spatial reference that our data is in? Go to Arc Catalog- file folder- metadata
Or Contents – right click properties- XY Coordinate System You can check out the projection.
Now that the trail map has been georeferenced, the next step is to use it to create a vector layer of the trails complete with attribute information.
So we go to the Bent Creek Folder and Right Click New- New File Geodatabase
Then we need to create a new feature class for the database so we right click on the geodatabase create a new feature class. Here you specify what kind of coordinate system your data is going to be in.