Tutorial - Using the Coverage-Analysis View

This tutorial assumes you have already created a Coverage-Analysis prediction set. If not see the section named: Tutorial – Preparing a Coverage-Analysis Prediction Set

On the Master-Control Palette click the “Maps” button then the “Coverage Map” item to access the Coverage-Analysis View. When you first access the Coverage-Analysis View it appears rather simple – and it indeed is simple. Yet even before we display predictions this view has several useful tools to offer. These tools range from simply moving your mouse cursor around the map and observing “mouse over” information - on the status line - display of location, grid sub-square, geographic coordinates, distance and azimuth to prefix and call search with great-circle-path plot and using ctrl-click on a target location to find it in the DX Gazetteer. With no prediction set displayed you can choose to have either long or short great-circle path “mouse over” information shown on the status line by clicking the Menu button and moving to Map Options and checking or un-checking the “Short Path” item. See the Coverage-Analysis View section for more on the DX List and prefix and call search features.

Display a Prediction Set -

Depending on which type of grid prediction set you created click the “Fields” or “Squares” button as appropriate. The “Fields” type prediction will be a bit easier to use for this discussion. Initially the Coverage-Analysis View displays the previously used – or displayed – prediction set if one exists and MUF so lets explore some available options before selecting a particular frequency.

When you display a prediction set five additional buttons appear between the “Squares” button and the “altitude control” – they are labeled Names, Values, Amateur, Contest and Selector. Further note the first four buttons are grouped in pairs, as their functions are mutually exclusive – clicking one turns off its companion. The DX List remains visible on the left side of the window for convenience. However a new tab named “Bands Key” appears beside the “DX List” tab – click the “Bands Key” tab to view the key that relates map colors to values. The default colors are blue for lower value and red for higher value. This seems especially intuitive when viewing signal levels or qualities - as the colors equate to blue for low value or cool and red for high value or hot.

Notice the extra “panel” toward the bottom of the window just above the status line. This extra panel is used to display “mouse over” prediction and prefix and call look up information.

The “Names” button causes the individual “grid field” or as appropriate the “grid square” identifiers to appear in each field or square. The field names are visible in the worldview but grid squares are one one-hundredth the size so their name identifiers can only be seen if you “zoom in” or lower the level with the altitude control.

The “Values” button behaves similarly to “names” - but instead displays the actual MUF value. The “values” display has two options – click the Menu button and look under “Prediction Options” for the “Show FOT” and “Show Band Name”. The “Show FOT” option changes the “Values” display to show the “Frequency of Optimum Traffic” and the “Show Band Name” option changes the value to show the “nearest amateur band” wavelength in meters – as commonly referenced.

The “Amateur” button changes the map colors to a special set, which relates each MUF value to the nearest amateur band - this button is only available when displaying the MUF or the BUF and makes the display much more applicable to actual on-air operation. The frequency ranges and colors are user selectable by clicking the Menu button and moving to Prediction Options and clicking the “Amateur Band Selections” item.

The “Contest” button changes the map colors to a special set that relates each MUF value to the nearest amateur “contest band” - this button is only available when displaying the MUF or the BUF and makes the display much more applicable to actual on-air contest operation. The frequency ranges and colors are user selectable by clicking the Menu button and moving to Prediction Options and clicking the “Contest Band Selections” item.

The “Selector” button opens a special grid-like view of all previously created grid prediction sets of the type – fields or squares – you are currently viewing. Although you can use the “navigator” control and move through available prediction sets, the selector allows you “direct access” to any prediction set saving you time and allowing you to more easily make comparisons between two or more. The selector also allows you to “sort” the display of prediction sets on any of the columns by clicking the “header” label. The default sort order for prediction sets is the order in which they were created – in the selector display click the “Month” column header to sort the prediction sets by month.

Just below the map near the middle is the “frequency selection” tool bar. The available frequencies – other than MUF and BUF – are the frequency set chosen when the prediction set was created.

Click the BUF button on the “frequency selection” tool bar to display the “Best Usable Frequency”. In general the name “Best Usable Frequency” may be a bit deceiving, as it does not mean the frequency will actually support a communications circuit. In this case “usable” has a meaning closer to “available” or “authorized” – as in licensed for use. The BUF for each grid field or square is selected from the frequency set chosen when the prediction set was created based on predicted values for each frequency. If the prediction set in use was not created with all amateur bands then the “Amateur” function described above cannot “color code” values for the missing bands but instead uses the next band that is included in the frequency set. For example if the prediction set was created using the five contest bands then this function will only display colors representing those five bands. If you want the full range of bands to be available then create a prediction set a complete frequency set - like the pre-configured “all bands” set.

WinCAP Wizard provides a unique feature with the BUF display as we also have “quality indicators”. A “quality indicator” – in this case – is a color used to indicate the circuit quality level using the terms noise, poor, fair, good and excellent. Each grid field or square is “outlined” with a color to represent the predicted circuit quality. The “quality indicators” are derived from the predicted signal-to-noise ratio – SNR – for the specific frequency determined to provide the best communications circuit. The top area of the “Bands Key” shows five small rectangular blocks that identify the colors currently selected as quality indicators. The quality indicator colors and related SNR ranges are user adjustable from the Master-Control Palette Menu – Options – Signal Quality Selections window. Use caution when adjusting the SNR values - the colors and SNR values in the Signal Quality Selections window are used by many “views” throughout WinCAP Wizard.

With the BUF displayed the CW and SSB buttons become available on the “select parameter” tool bar on the right edge of the window. Selecting the mode in use is important when describing “quality” as the “bandwidth” of the signal must be considered. However WinCAP Wizard handles the complicated calculations for you so you only need dig deeper when and if you have a desire.

You may find it useful and informative to notice the “mouse over” prediction information panel shows the predicted BUF, signal quality information and the actual predicted SNR. The displayed SNR is in the standard 1 Hz bandwidth and therefore is much higher than what you would expect for a mode using a wider bandwidth - like 3 KHz for SSB and 300 Hz for CW.

When first accessed the prediction set typically defaults to the current “hour” Zulu. The date however defaults to the fifteenth of the month. This is because the VOACAP predictions are actually “monthly mean values” and are closest during the period in the middle of a month. If the prediction set was created using the “daily coefficients” option the day then defaults to the day specified with that option. Both the hour and day are easily changed with the “step” controls and the drop-down lists.

Activate – If the prediction set is for the current month the “Activate” button is available. When the activate button is down the displayed prediction set and gray line stay in sync with the current time. Changing the hour or day controls “turns off” the activate function – for obvious reasons.

When a specific frequency is selected for display – using the buttons on the “frequency select” tool bar – seven predicted parameters become available on the “select parameter” tool bar near the right edge of the window. The available parameters are mostly the same as those available on the charts and reports. Here’s a brief description of the available parameters - with additional comments where useful.

dB > µV is dB greater than 1 microvolt, dB > µV into 50 ohms – this value is easily converted into the familiar “S-Units” - displayed by the meter on most radio receivers – as follows:

     +34 dB > µV is S9 = 50 µV on 50 ohms = -103 dBW on 50 ohms

The dB > µV display has an optional “fixed-signal levels and colors” mode. The option is controlled from the Prediction Options sub-menu “Fixed-Signal Levels” item and the colors are adjustable from the similarly named item on the Map Options sub-menu. If you use the “Fixed-Signal Levels” option you will likely want to change the map boundary colors by accessing the Map Options and “Political Boundary Color” item – black seems to be a good choice with the “Fixed-Signal Levels” option.

Rel – Reliability is the percent of time the predicted SNR exceeds the “Required Reliability” specified when the prediction set was created. The default required reliability in WinCAP Wizard is set to 90% - which is the industry standard. In other words “Reliability” is defined as the fraction of days that successful communication may be expected at a given hour within the month at a specific operating frequency on the undisturbed days of the month. The undisturbed days of the month are generally considered to be when the geomagnetic index Ap is less than or equal to 27 and the K index is less than or equal to 4.

SNR – Monthly median signal-to-noise ratio (1 Hz BW) in dB – with this parameter the CW and SSB buttons are enabled so the “quality” relevant to the desired mode can be calculated.

SNRxx – monthly median signal-to-noise ratio (1 Hz BW) in dB at the specified “Required Reliability” - For example, at the default-required reliability of 90%, SNRxx is the signal-to-noise ratio exceeded on 90% of the days. With this parameter the CW and SSB buttons are enabled as the “quality” is relative to the desired mode.     

TAngle – Signal “take-off angle” at the transmitter for most-reliable mode

MUFDay – fraction of the days of the month that the operating frequency will be below the mode MUF

Req Pwr – the “required power gain” is the additional – or excess where appropriate - gain needed for the communications circuit to reach the specified quality and required reliability. This parameter is unique to the coverage view and is interesting and potentially useful.

For each of these parameters be sure and observe the “Bands Key” and the information panel toward the bottom of the window just above the status line.

A unique and powerful feature of WinCAP Wizard is the ability to import Cabrillo-log files and “geocode” the stations worked locate - by means of coordinates - and mark them on the map; locating by means of coordinates is known as plotting. For additional information see the Contest-Log Manager section.

The current display of the Coverage-Analysis View can be saved as a BMP or GIF or JPG type graphic file. We strongly prefer the GIF as the file size is considerably smaller than the other two types and image quality is still better than the JPG. However there is some degradation in image quality so if you need the best quality picture use the BMP type. These images are labeled sufficiently so that you – or someone else – can easily determine what the map image is showing.

The “Animator Preview” tool is used for creating and saving animations of several hours of map images. See the Animator Preview section for more information.