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This page is a listing of tips submitted by the individuals who use our lab and software. If you have a shortcut or other advice you would like to give please send it to msl@esf.edu.
Remote Sensing
GIS
ArcView GIS version 3.x
ArcGIS 8.x
Other
Remote
Sensing
Rotating images in ERDAS Imagine
1. Display an image in a viewer
2. Go to Raster|Geometric Correction
3. From the Set Geometric Model dialog, select Affine and click
OK
4. From the Affine Model Properties dialog, input correct parameters
(i.e.enter the Rotate Angle value), click Apply
5. From the Geo Correction Tool select the Display Resample Image
Dialog Icon
6. In the Resample Dialog, enter the output file name, click
Ignore Zero in Output Stats, then click
OK
7. When displaying the rotated image you must deselect Orient
to Map System from the raster options.
Importing a LANDSAT 7 ETM+ HDF formatted image
Background: HDF or Hierarchical Data Format is a data storage technology specifically designed to store scientific data. ERDAS Imagine Version 8.6 now has a means of importing HDF formatted data files into Imagine's native "IMG" format. The following steps should be taken to import a LANDSAT ETM+ image from the HDF format.
1. After launching ERDAS Imagine 8.6, click the IMPORT tools button.
2. In the Import/Export dialog box, use the drop down list tool on the Type field and scroll to the bottom of the list. There, you should select the "TM Landsat-7 HDF Format" file type.
3. Set the Media type to the appropriate device
4. Navigate to and select the file to be converted using the Input dialog boxes.
5. Navigate to the folder and name the file that will store the results of the import function on Output side of the dialog box.
6. ERDAS will then display a "TM Landsat 7 HDF Format Importer" window. Note the image information that is displayed in the window.
7. Select the appropriate Radiometric Calibration Option for your needs.
8. Click on the OK button to begin the file conversion..
9. Landsat TM+ images have several reflective bands. The visible and inferred bands (1-5, and 7) are imported and combined during a single import operation. To import the thermal bands (6.1 and 6.2) and the panchromatic band (8), you will need to execute the import function multiple time. Us the Next Image button to scroll through the list of available bands.
GIS
Reprojecting in ArcView
1. Open an new view and add the theme that
needs to be changed
2. Click View->Properties and change the projection to the
correct form, click OK
3. Go to Themes and save as shapefile
Rotating your view in ArcView layouts
1. 1. Bring the View into the layout inside
a view frame.
2. Simplify a view frame by converting its contents into a single
graphic
object. Note that simplifying a view frame
causes its associated legend and
scalebar frames to turn into empty frames.
Thus, when you have a view frame and associated
legend and scalebar frames, simplify the legend
frames first and then simplify the view frame.
3. Group the simplified graphics.
4. Insert the grouped graphic into the 'North Arrow Manager'
by running the
following script with the layout window active
and the grouped graphic selected.
myGraphic=av.GetActiveDoc.GetGraphics.GetSelected
NorthArrowMgr.Merge(myGraphic)
5. Delete the view graphic from the layout.
6. Use the 'Frame' tool to click/drag a 'North Arrow' frame.
7. Choose your view from the 'North Arrow Manager' gallery of
graphics. Set the rotation of the
view.
8. Reset the rotation as needed by selecting the view and changing
the rotation value from 0 to 360.
Notes:
1. This turns the view into a 'North Arrow'
type of graphic element, and thus
can no longer be live-linked and turned back
to the original view preserving
its scale.
2. Complicated views can fill up your North Arrow Manager ($HOME\north.def)
very quickly. Make sure that you have a path
designated to a HOME environment variable in your
autoexec.bat. The new 'north.def' file will
be written to the HOME path. You may need to move or
delete this file from time-to-time, if it gets
so full that ArcView seems to freeze when you try to
insert north arrows into your layout. See page
14 in your ArcView 2.1 install guide for more
information about the HOME variable (page 11
for ArcView 2.0)
3. Do not ever delete the 'north.def' file that is found in your
$AVHOME\etc
directory.
4. GraphicText in the original view will lose rotation if other
than zero, and the size of GraphicText
will change and vary dependent on the rotation
that you place on the new north arrow.
Segmentation Error in Spatial Analyst
using Slope or Aspect
If a segmentation error is occurring on Windows
2000 (or WinNT) when using the Slope or the Aspect commands:
1. Check the path to the $HOME directory to be sure there are
no spaces in the file or folder names.
2. If 1 doesn't work make a separate folder an reassign that
one as your working directory.
Disappearing Feature Class
If you are processing a coverage and your feature class diappears - make sure you don't have both polygins and points in the coverage. If you do you will need to build your original coverage as a polygon coverage and convert your points to label features. You will lose your point topology. If this is a problem you will have to copy the coverage to a new coverage and built that one as point. To perform the build using ArcCatalog: right cligk on the coverage folder and select properties. In the general tab there will be a list of the features and their topological status. Build the polygons.
What is ArcGIS
ArcGIS is ESRI's latest GIS software. Developed to be scalable, ArcGIS has varying levels of licenses that give increasing amounts of functionality. The product is comprised of a three applications, ArcMap, ArcToolbox, and ArcCatelog..
ArcMap is used to visualize and analyze spatial datasets.
ArcToolbox offers a wide range of spatial data manipulation utilities. This application is used for data conversion, changing geographic projections and provides graphical user interfaces to many of the command line ArcInfo functions and tools.
ArcCatelog provides a "Windows Explorer" like interface that is used to create, delete and move spatial datasets. Using this product assures that the complex data structures of spatial datasets are maintained while being moved or copied.
I can do this in ArcView, how do I do it in ArcGIS
ArcView: Multiple map layouts in a single project
ArcGIS: ArcMap allows only one map per map document (MDX). You must open multiple session of ArcMap to create multiple maps. Look into using styles and templates to ease the trouble of making multiple map documents.
ArcView: Create a new shapefile from selected elements of a theme in a view.
ArcGIS: With the elements selected, highlight, in the table of contents, the layer you wish to subset. Click your RIGHT mouse button with the cursor over the selected layer. Click on the DATA menu. You should then see an EXPORT DATA option. This option will prompt you for a new filename.
ArcView: Extension for reading GeoTIFFs, ERDAS Imagine and MrSIDs and AutoCAD iles need to be activated in order to load these features into a map.
ArcGIS: No additional extensions are needed to load non-ESRI image files into a map.
ArcView: Opening the table associated with a spatial dataset.
ArcGIS: Right click (or double clic) the layer in the table of contents. Select the Open Attribute Table menu option.
ArcView: Writing scripts is Avenue.
ArcGIS: This packages uses Visual BASIC for Applications with ArcObjects for customizations
Other
Changing File Associations
1. Open Windows Explorer
2. Go to View->Options
3. Click on the File Types tab and change
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