Alaska Science Center
DOUGLAS ARGOS-FILTER ALGORITHM
Loading this Extension: Spatial Tools is an ArcView program extension which must be run simultaneously with Spatial Analyst. After downloading, unzip the .avx file directly (or unzip to a temp directory, then copy) to the ArcView EXT32 folder. Start the ArcView program, click on "file" and go to "extensions". From the list of available extensions, select Spatial Analyst, then Spatial Tools and click "ok". The collection of new functions will now be available through menu choices, tools, and buttons described below. When installing version 3.2 (10/99), Spatial Analyst will automatically load after selecting the Spatial Tools 3.2 extension.
Note...you must install the g2i.dll file in to the $AVBIN directory (which is now included in the latest version, v. 3.2).
Using this documentation: Click on the menu bar above to go to the major headings and then click on either the subheading list or the image map of menu choices or buttons. Click on the return button to get back to the subheading list.
For any questions or problems regarding this documentation, contact email@example.com.
Spatial tools is an ArcView extension which provides a collection of grid tools made available through the program's GUI (Graphical User Interface). Menus, Tools, and buttons provide access to various spatial modeling and analysis capabilities such as geometric transformations, mosaicking, resolution alteration, data clean-up and spatial analysis. Spatial Analyst must be loaded simultaneously.
Requirements: ArcView and Spatial Analyst. This program will work in versions of ArcView on PC, UNIX and Macintosh hardware. On the PC platform it is recommended that a Pentium or Pentium Pro 200 or faster be used with this program and at least 32 megabytes of memory, since Spatial Analyst must be running simultaneously.
Other grid operations and functions not currently available through Spatial Analyst or Spatial Tools menus can be accessed through the use of the additional extensions and Avenue Requests. Help for these requests and extensions can be found in the ArcView On-Line Help Documentation and/or at http://www.esri.com/.
The majority of functions in Spatial Tools operate primarily on grid theme data (ARC GRID format). The exceptions are the Profile and Profile with Feature Points operations which require a combination of active grid, line and point feature themes, and Clip Grid, which requires a selected graphic object as well as an active grid theme to perform the analysis. The menu choices Set to View and Set from View each require a separate existing view in the project and the Type in to Link and Type in from Link work with an existing table (which can be created using the Create Link Table option).
Menu choices are performed on selected (active) feature themes, after which the user is prompted to enter or select from a list of variables. Tool buttons are utilized by clicking the tool and then clicking in the view to perform the function.
Select a Menu Item
Addition to Version 3.2 menu (10/99):
Select a Tool
Cells in common or overlapping areas are assigned values based on the sequence of grids entered (highest priority goes to the grids entered first).
In the following example, 3 grids were mosaiced to create a new grid with smooth boundaries.
Select graphic object
Choose "clip inside" or "clip outside'
The following set of tools are used in the georeferencing/warp operation for grid data sets:
The following bathymetry grid was aggregated using maximum values for depth and a cell factor of 3. The resulting grid been resampled to a coarser resolution.
Takes a grid or set of grids that were created from a true color image and converts them into a BSQ, BIL, BIP, JPG or TIFF image.
The g2i.dll file must be placed into the bin32 directory to work properly.
Smoothes data by replacing cell values in the active grid with the majority (most frequent) value of neighboring cells. Select diagonal neighbors (true/false) and halfok (majority or half) options to decide which and how many of the neighboring cells will be used to determine majority values.
In the following example, the majority filter function has smoothed out the data by replacing misclassified cells (dark green areas of vegetation occurring in water) with new values using the most frequently occurring values of neighboring cells.
Creates a region for every contiguous group of cells with the same value.
In the following landcover grid, the original values which represent "shadows" (displayed in black) were set to to No Data by entering a count of 1500. The new grid represents the original values for all data with a count greater than 1500.
Uses a mask grid to replace NoData cell values of the active grid (input grid) with the values of the nearest neighboring cell.
Cleans (smoothes) transition areas between grid zones using expand and shrink methods.
Shrinks linear features in the active grid to one pixel width. Prompts for the following variables:
notBinary (TRUE = all values other than No Data are thinned. FALSE = only values greater than 0 are thinned).
Changes the resolution of the active grid by interpolating values using a chosen resampling method (nearest-neighbor, bilinear, or cubic).
The following histograms illustrate the default values used in creating uniformly and normally distributed random grids:
Creates a table containing various geometric calculations for each zone in the active grid.
Used to create chart profiles of line features (streams, roads, trails, etc.) using a line theme and an an elevation grid theme. Requires two active themes, the first a line theme (with records selected) and the second an elevation grid theme. Merges selected lines, then finds interval points along the merged line at equal intervals. User is queried for how many divisions of merged line. Outputs a dbf file of distances starting at the lowest interval point and including all interval points and corresponding z values. Outputs a line graph (profile) of distance from origin vs. z values if no more than about 100 interval points are produced.
In this example, the selected stream (shown highlighted in yellow) was profiled, using 5 equal divisions. The chart below shows distance and corresponding elevation values.
Used to create elevation profiles of selected lines and selected point features. Requires three active themes, the first a point theme (the feature points), the second a line theme and the third an elevation grid theme.User is queried for how many divisions of merged line. Outputs a dbf file of distances starting at the lowest inerval point and including all interval points, feature points and corresponding z values. Dbf table contains a "Type" field indicating whether a distance is an interval point or a feature point. Outputs a scatter diagram graph (the line profile) of distance from origin vs. z values if no more than baout 50 points are produced.
Conducts a visibility analysis of a line or point file. This function requires the following fields in the input FTab, which are used to control the visibility analysis. These Fields are SPOT, OFFSETA, OFFSETB, AZIMUTH1, AZIMUTH2, VERT1, VERT2, RADIUS1 and RADIUS2.
If not specified, the default values in the Visibility Tool are are set as follows:
Creates Warp desired points (creates a "to link" in the "to" view). Click on the desired location in the georeferenced dataset to start building a list of "to links" (Points will automatically be labelled). Use the delete links button to remove incorrect links from the table.
Click the button, then enter the number of degrees desired (and the resampling method to be used if multiples of 90 degrees are not used). (See previous section on Resampling methods, for a description of the 3 types of interpolation).
In this example, a new grid was created, rotated 90 degrees around the original grid's lower laft-hand corner.