ArcMap import & conversion
toolbox functions. Identifying the formats required for a desired function is the first step in using some of the many toolbox or modeling features in ArcMap. A good place to start is to take 5 minutes for an ArcMap can only import Comma-Separated Values, or CSV files – Tab delimited files will not work. Data can be saved as a CSV file in programs such as Microsoft Excel (be sure to use labels for multi-column tables). CSV files for import cannot contain any extended ASCII characters (only numbers and letters). To remove extended characters, use a Unix/ Linux terminal window to execute the following tr filter to remove all non-printable ASCII characters: Add the CSV file to ArcMap using the Add Data button, at which point it will be added as an ArcMap Layer. You must be under the Source tab to view these files. Right click on the name of the new ArcMap layer and go to Display XY Data. Set the X Field to longitude, the Y Field to latitude, and the Geographic Coordinate System to WGS 1984.prj. Click OK and the data will be displayed on the map as a new layer entitled Events. Point data is a good format for plots of station data for cruise tracks or to show data at stations. Data can also be used with other layers such as topography and coastlines. Additional functionality requires that the file be converted to a shape, raster or polygon format. Right-click/ Data/ Export data to save an ArcMap layer as a shape file (.shp) & 6 other associated files. (Make sure an appropriate coordinate system has been applied before exporting). Shape files have all of the features of a layer with the important additional ability to do computations in the table attributes. ArcToolbox/ Conversion Tools/ To Raster/ Point to Raster. This is the simpliest method to generate a raster. THE RASTER SHOULD BE COMPARED TO THE ORIGINAL DATA TO ENSURE THAT THE FEATURES HAVE BEEN FAITHFULLY REPRODUCED. The cell size for the raster interpolation can be adjusted to optimize interpolation. ALTERNATIVE METHOD TO GENERATE RASTER: Arc Toolbox/ 3D Analyst Tools/ Raster Interpolation. This contains a Kriging method. Kriging is the most accurate translation method and may be required for sparse data sets that do not interpolate well using the standard Point to Raster function. Rasters are one of the the most useful formats for the analysis and modeling of oceanographic data. They can be used for classification, grid math, contouring (Spatial Analyst Toolbar), resampled (ArcToolbox/ Data Management Tools/ Rater Processing/ Resample), various types of block calculations (such as averaging to reduce resolution – ArcToolbox/ Spatial Analyst Tools/ Generalization/ Aggregate). ArcToolbox/Conversion Tools/ From Raster/ Raster to Polygon – Not yet verified – does not work with standard rasters from III – Need to create integer raster first? Source.