If you want to be an expert with other Digital Atmosphere users and with tech support, here's the definitions of some of the terms that we use.

Active level. At any given moment, Digital Atmosphere will only perform analysis or plotting operations for a certain type of data or height/level (such as surface, 300 mb, NGM model output, etc). Active level describes which one is the current one. You change it using the Level setting on the Time Toolbar.

Analysis. See objective analysis.

Derivative field. The vorticity, divergence, or advection of a selected primary field.

Dialog box. Any box (window) that pops up on the screen temporarily asking you to enter or click something.

Formatted binary data file. The end results of File, Import, where tables of raw data are stored on disk and made available to the plotting or analysis routines. These files consist of compressed data and can only be modified using the File, Quality Control function.

Importing. The process of "crunching" raw data. This is how you feed new data into Digital Atmosphere. The data is stored in formatted data files.

Isoplething. The process of Digital Atmosphere drawing contours, or lines, on the screen, as the result of an objective analysis. Isopleths are not "plotted"; they are "drawn".

Map attribute file. A small file (36 bytes) that is paired with a geographical bitmap file to provide mathematical mapping information about that image. A map attribute file has the file extension "ATR".

Map generation. Forcing Digital Atmosphere to draw a customized map based on latitude, longitude, and zoom settings that the user selects.

Objective analysis. The process that Digital Atmosphere undergoes before it can show a contour or isopleth. It consists of looking at data at randomly-spaced points, mapping it to a grid, and running smoothers on the grid. In the context of this user's guide, I will refer to objective analysis as simply "analysis", and refer to human analysis as "hand analysis", etc.

Ocean fill. The blue color that Digital Atmosphere usually draws in oceans and lakes.

Plot. See station plot.

Primary field. An atmospheric property that the user chooses to analyze. The user may also force Digital Atmosphere to calculate a derivative field of the primary field.

Raw data file. The original weather data from online services, the Internet, etc, that is fed into Digital Atmosphere when the user selects File, Import. First, the file is copied and filtered to produce a clean data file (C:\DIGATM\DATA.USR), and then data is imported, producing a formatted data file.

Station plot. A small grouping of numbers and symbols that depicts the observed weather at a given location. Plots are not "drawn"; they are "plotted".

Status panel. The window that shows the clock, the active level, data display options, and import filters.

Sterilized data file. A temporary file containing original raw data that is produced whenever the user imports data. It contains no control codes or extraneous characters. The sole purpose of a clean data file is for the File, View Raw Data command and for Digital Atmosphere functions where English-language bulletins are drawn on the screen (such as tornado watches, convective outlooks, etc). Weather data plots and analyses do not come from this file, but from the formatted data file.

Topography. The multicolor shades that can be manually drawn on landmasses to represent terrain.

Upper air. Involving any level besides the surface.

Workchart.  A graphical pane containing one map and all annotations placed on that map (geographical plus meteorological fields).