Difference between revisions of "Visualizing a land cover map of Fort Ord, California"
From CCoWS Wiki
(→Visualizing Fort Ord with the Renderer) |
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# Add the NAIP imagery | # Add the NAIP imagery | ||
## On the '''Raster''' tab load the Fort Ord NAIP imagery (click '''Open''' and navigate) | ## On the '''Raster''' tab load the Fort Ord NAIP imagery (click '''Open''' and navigate) | ||
− | ## Click the '''C''' and | + | ## Click the '''C''' and check the '''RGB (true color) |
Revision as of 12:51, 20 November 2009
Contents
Outcomes
- Render Fort Ord in a 3d realistic virtual reality
- Use your land cover map to populate the visualization with trees and shrubs where appropriate, and at a density dictated by your % green cover map
Prerequisites
Data
- Fort Ord land cover map derived from Landsat (and associated land cover metadata)
- Fort Ord % green cover derived from Landsat
- DEM (download from USGS - http://seamless.usgs.gov/index.php)
- NAIP imagery (also download from USGS)
Recomended Reading
Tarsier tutorial: Raster resampler
Tarsier tutorial: Simple fly-through
Intorduction
In your remote sensing class (external link perhaps?) you have developed and ground truthed a land cover map. . .
Simplify the land cover map
Your land cover map has too many classes for our purposes. We will want to reclassify the map distilling the classes down to just three: trees, shrubs, and other. This process could be done in other programs as well, but here is how it is done in Tarsier:
- Open Tarsino
- Open your Fort Ord land cover map:
- ->File ->Open
- Navigate to your land cover map and double click the file
- Open the Raster Lookup tool:
- ->File ->New ->Tools ->Raster Lookup
- Load the land cover map into the Raster Lookup
- In the Raster Lookup view, use the drop down box next to Input Raster: to select your land cover map
- Click the Find Values button
- To the right of Lookup Table Data:, click the View button. This will display a table with a column, Input, for all the values from the input raster (your land cover map) and another column, Output, that will dictate the new values for the reclassified map.
- Reclassify the map.
- Right now the "Output" column is filled with "-9999" which is the default null value. This will be the value of your "Other" class.
- For any input value that you think represent forest or trees, edit the corresponding output value by typing a "1" into the cell.
- For any input value that you think represent shrubs or chaparral, give the output value a "2".
- After you have finished editing the table, click the Execute button on the Raster Lookup view.
- View and save your reclassified raster
- To the right of Output Raster 0: click the View button
- Save the raster: With the Raster View window active, ->File ->Save As. . . Save your raster to an apropriate location. Tarsino will recognise file names up to 255 characters (no spaces), so name your file something informative like "'Original file name'_ReclassifiedTo.Trees.Shrubs.Other.'yymmdd'.tra".
Creating Raster Symbol Scheme
The reclassified map has three classes, one of which is null (Other). You now need to let Tarsier know how you want the non-null classes to be visually represented in a render. One way to do this is to create a symbol scheme.
- Export your reclassified map to a Raster Symbol Scheme
- Make sure your the raster view window is active, if not click on it
- ->Raster ->Export to RasterSymbolScheme (This should open a new view window)
- In the RasterSymbolScheme view you will see a list of all the non-null values from your reclassified raster. Click on unnamed 1 to edit its properties
- Recall that the value "1" is to represent trees, so in the box next to Tag type Trees
- Set the Max Height to something reasonable for a Fort Ord tree, maybe 7
- Click Load Texture and navigate to your Oak.bmp
- Set the Transparent Color bar to the background color of the *.bmp file to make it transparent
- Similarly edit the properties for the shrub class (unnamed 2)
Visualizing Fort Ord with the Renderer
- Open the Renderer
- ->File ->New ->Data Views ->Render view
- Make the Fort Ord terrain
- On the Raster tab next to the Relief box, click Open
- Navigate to your Fort Ord DEM (UTM)
- Once it is loaded, click the Make next to Terrain
- Add the NAIP imagery
- On the Raster tab load the Fort Ord NAIP imagery (click Open and navigate)
- Click the C and check the RGB (true color)