Introduction to Radar ViewPoint

This information is directly taken from the on-line help system designed into Radar ViewPoint. You can use the program's on-line help to further explain concepts and features identified below.

Program Description:

Radar ViewPoint is a state of the art computer program designed to be a radar data analysis tool useful in missing aircraft searches, accident analysis, operational error analysis and documentation, airspace encroachment analysis and documentation, and computer aided training. Over four years of development went into the technology of Radar ViewPoint.

The most dominant feature of Radar ViewPoint is the chart view window. The chart view window is an interactive window that shows, at any scale, an aeronautical chart along with radar data and user defined information. Simply point to objects on the chart to get a one line description of the location. Many chart objects let you click on them to get even more information. Also, you may pan and zoom the chart view window to display any area of the United States.

Radar ViewPoint contains several highly optimized databases including: radar data, airports, navaids, fixes, airways, special use airspaces, and state and county boundaries. Also, custom waypoints can be created with the user defined waypoint database. All databases are stored in a proprietary format that enables Radar ViewPoint to very quickly: draw the chart to any scale, look-up what is at any coordinate or area, or search through the database given a partial name, city, or state. Database Construction

Before any radar information can be displayed or analyzed, it must be translated into a .RAD file. This file format is the key to Radar ViewPoint’s extremely fast performance when dealing with large amounts of radar data. Included with Radar ViewPoint are several DOS utilities that are used to produce the needed .RAD file. The utilities have proven to work with very large quantities of radar data, over 50,000 radar hits can be managed.

Both NTAP and CDR radar data formats are supported. Each radar format has a special conversion utility that molds the raw data into an intermediate form that we call the Universal Radar Format. The Universal Radar Format (URF) has several benefits: 1) it can be printed and verified, 2) it can be merged with other URF files, 3) you can manually enter radar data from within a standard word processor or text editor.

Once the radar data is in the URF form, the MAKERADR utility will turn it into a highly optimized .RAD file for use by Radar ViewPoint. Here are the various conversion utilities and their use:

PRERADAR Converts an NTAP file (LST3 format) to an .URF file.
CDR2URF Converts a CDR file to an .URF file. The CDR file can be either a Target (TG) or Track Data (TG) report.
NTP2URF Converts an .NTP file to an .URF file. An .NTP file is created by the Single Track NTAP database within Radar ViewPoint.
MAKERADR Converts an .URF file to a .RAD file (usable by Radar ViewPoint). .RAD files are the highly optimized files that Radar ViewPoint uses to display and analyze the radar data.

Database Construction Examples:

To convert an NTAP file named NTAP45.SAR for use with Radar ViewPoint, you would type something like this:


To convert a Sacramento CDR file named FLT405.CDR for use with Radar ViewPoint, type:

Both processes usually take less than a minute (depending on data base size.)

Radar Basics:

Once the .RAD data file is constructed, Radar ViewPoint can 'open' the radar data file to present the respective radar information (see: Open... command within the Radar menu).

When a radar data file is opened, the program resets the radar time window and other radar settings to display all radar targets; however, you must manually position the chart view window to display the area of interest.

Displaying radar information is controlled from within the Radar Display Control dialog and is brought up by the [F3] key or by selecting Display Settings... from the Radar menu. This dialog gives access to all of radar display mechanisms including the separation bubbles and target labeling. Target information for any viewed radar target can be obtained by simply pointing the mouse pointer to the target. The upper status line will show the target's information. You may obtain all information known about the target or use the target as the radar reference point by pressing either the left mouse button or the [Enter] key--this brings up the Radar Target dialog.

The radar reference point (synonymous with reference target) is used in many of the radar analysis tools. The reference point most often matches an existing target; but, it can be defined as any desired point in time. The most common uses of the reference point are for setting up an animation window, and for displaying the relative speed between two radar targets.

Each radar target has several pieces of information associated with it: time, location, altitude, aircraft identifier, beacon code, track number, radar subsystem value, target attribute, display symbol, and label placement setting. The time, location, altitude and radar subsystem values cannot be modified whereas the other values are modifiable.

Building a Track: The target attribute plays a vital roll within Radar ViewPoint for building a track from arbitrary targets. The Follow Track... command from the Radar menu attempts to piece together a track of radar targets. This feature scans the database of radar targets, one by one, marking targets that fall within a pre-set speed range from one another. The targets are marked as 'Retained' and can later be edited to the desired settings from the Attribute Editor. You may also build a track manually by using the Area Editor. See also: "Editing Radar Data" below, or How to..."Building a Track from Un-tagged Targets" within the on-line help.

Tracks are required for several analysis tools such as: separation bubbles, separation analysis, and supporting the NTAP database.

Radar Animation can be performed with radar data using two major animation techniques: manual (normal), and synchronized. Both animation techniques are performed by Radar ViewPoint by simply shifting or modifying the radar time window. Manual animation involves using the function keys to advance, backup, stretch or shrink the radar time window. In synchronized animation, the radar time is automatically advanced by an accurate system clock. While in synchronized animation mode, the manual animation commands (function keys) can be used to adjust the clock.

The trickiest part of doing an animation is setting up the initial radar time window. The standard method to start a manual animation sequence is to utilize the Center Animation about Ref. Target command in the Radar menu after first defining the reference point (see "The Radar reference point..." above). Otherwise, the initial time for animation can be defined within the Radar Display Control dialog by setting the radar time window values and animation increment as needed. Editing Radar Data can be accomplished within Radar ViewPoint globally or within a specified area of targets. The Aircraft ID, Track number, beacon code, display symbol, label placement, and attribute can be modified by either of the two radar editors. The Radar Attribute Editor edits the entire set of radar targets. It searches for targets that match specified attributes and/or values. Matching targets are then modified to the desired attribute or value. The Radar Area Editor is used to modify a selected area of targets.

Chart Basics:

The most dominant feature of Radar ViewPoint is its chart view window. This window displays an aeronautical chart, radar data and other features at virtually any scale. You may zoom-in to get a close look at an area, or zoom-out to get a broader view. You may also shift (pan) the chart view a partial screen or a full screen up, down, left or right by using the arrow-keys or scroll-bars. You may also change the amount of detail shown by editing the preferences, or by increasing or decreasing the preference level. See also: Navigating through the chart.

Most displayed objects have a name or description. When the mouse pointer rests on a named object, the information-bar displays a brief description about the object. You can get more detailed information by clicking on the object or by pressing the [Enter] key.

Sometimes, there are several overlapping objects on the chart; however, only one object will be presented in the information-bar. You may cycle through all objects at the mouse pointer by pressing the [space-bar] key. Each [space-bar] will select the next object and display its information within the information-bar.

Preferences and Preference Levels:
To reduce clutter on large scale charts (large area depicted in the chart view window,) Radar ViewPoint incorporates a multiple preference level system. There are eight different preference levels, one through eight--with eight having the most detail. Each preference level has a set of preferences that describes the information to be displayed for that level.

Radar ViewPoint automatically selects a preference level based on the chart's scale. So, when the chart is zoomed-in, the preference level is automatically increased which displays more detail.

You may modify the preferences for the displayed preference level by selecting Preferences within the View menu. When changes are made to a preference level, changes are intelligently propagated through the other preference levels (any added detail is added to higher levels, and removed detail is also removed from the lower preference levels).

The automatically selected preference level for the displayed scale can be manually increased or decreased by pressing the [Ins] or [Del] keys respectively. These keys correspond to the Increase Detail and Decrease Detail options within the View menu.

Accuracy Statement

Airways Technology has exerted much effort to assure the accuracy of the calculations, data and depiction of data. The great circle math routines (used for distance and bearing) are implemented from Sodano's method, as also used by the FAA for determining routes, use double precision math routines and use the WGS 84 ellipsoid. However, when the distance being measured is less than 1.25 nautical miles, a standard X,Y grid is used after properly scaling both the X and Y axis to the ellipsoid. The X,Y technique is used because the great circle routines lose their accuracy for these very short distances.

Most aeronautical data is from the FAA--the FAA has no explicit statement of accuracy since much data is obtained from airport management and not verified by the FAA. The crash data is from the Air Force Rescue Coordination Center (AFRCC). The placement of most crash sites is normally accurate to +/- 1/2 a nautical mile--the completeness of the crash data is of an unknown quantity, but the listed crashes are supposedly only those crashes whose debris was initially not scheduled to be removed.

The state and county boundaries are from a USGS 2,000,000:1 scale digital atlas. To reduce database size, border points are thinned so that border segments (straight lines) will be over .5 NM long. Thus, portions of a border segment could possibly be .5 NM off of the actual border, especially when the actual border is very jagged. Also, the USGS data is organized by regions and the joints between regions don't always match (1 NM variations between adjacent regions have been observed.)

The Coordinate Calculator double checks all values with internal formulas. If a the difference between known and calculated values exceeds 0.15 and is over 1.5% different, then a consistency error is displayed. Also, a consistency error for an angle is given when the known and calculated angles are 0.2 degrees or more apart.

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