V-Soft Communications Newsletter: 03/22/06
In this Newsletter:
Hopefully, most readers have received a mailing about this year's training seminar at the Circus Circus hotel in Las Vegas. The training, which will last two days (April 22 and 23), will review broadcast engineering techniques using Probe 3, AM-Pro, FMCommander, SearchTV and other programs. It is anticipated that there will be breakout groups for primary interest subjects, such as AM, digital LPTV, and NCE-FM. This is an excellent way to learn first hand how these powerful tools work. The cost for the program is $450 (or $495 for non-tech support subscribers), and includes breakfast and lunch both days. Time is running short so call or email Kate Michler at 319-266-8402 to enroll.
The FCC will allow an LPTV analog station to file for a flashcut digital operation on the same frequency. The maximum digital LPTV power is restricted to 15 kW for UHF and 300 watts for VHF. Some analog channels will work for digital stations, but others will not. V-Soft Communications has completed the process of adapting the FCC's actual FORTRAN program for doing LPTV digital interference analysis. This program provides an excellent way to see what the FCC would see if they examine your allocation work. The program runs on our in-house Sun Sparc Workstation and can be accessed through the interface below. (Access to the Internet is required)
If you are one of our current remote DTV analysis users or you would like to become one contact John Gray, at firstname.lastname@example.org for the interface and instructions.
V-Soft will be unveiling its new AM ground conductivity program at this year's
spring NAB convention. This program, with the working name of
"Conductivity", takes in measured field strength values of AM stations, and match ground conductivity curves or partial curves. The program graphs the field strength values in this process (see below.)
(Click the thumb nail graphic above to see the clarity of
Connectivity's screen and printed graphics.)
(Click the thumb nail graphic above to see the clarity of Connectivity's screen and printed graphics.)Final output, shown below, shows you where the conductivity breaks along the measured radial. The graphs are produced in a “What you see is what you get” format allowing the user to create labels and otherwise provide user notes on the graphs. This program is a stand alone program, but is most useful as a companion to V-Soft Communication’s AM-Pro allocations program.
If you are interested in being a 30-day beta tester for the AM ground conductivity program, email Adam Puls or call 1-800-743-3684.
And a reminder: we are also looking for people knowledgeable in C/I microwave calculation methods to be beta testers for our microwave frequency search program. If you are interested please let us know. Top
Ever wonder why you can't get that DTV station?
In previous newsletters we have discussed the advantages of using the Shuttle Radar Topography Mission (SRTM) Shuttle Terrain. The 3 arc-second elevation database, taken from, space also includes buildings in the elevation profiles. The Longley-Rice Probe map above illustrates a new degree of prediction clarity achieved from using the SRTM data enhanced with known obstacles from the NOAA Air Navigation Obstruction database. The obstacles we are talking about are tall buildings, above 700 feet, located within 25 km of the Empire State Building. For the study shown above, 31 of New York, New York's tallest buildings were loaded, as 1 second (about 100 feet square) polygon obstacles, into Probe's new obstacle feature, which is available in basic, standard and professional levels. Loading the building obstacles provides fill for the 3-arc second SRTM which has elevation points at approximately 300 feet intervals.
In viewing the map above, the reader can clearly see that there are two trails of low level signal areas fanning out to the east, southeast from the tall buildings in mid and lower Manhattan. The station of interest is a fictitious channel 40 DTV station located in New Jersey. The trail, identified by the tiny white signal areas surrounded by blue 41-48 dBu signal areas, is the result of the obstructions to radio waves caused by the tall buildings in the path. Access to the NOAA building obstruction polygon data will soon be available through a new version update of V-Soft's IDTowers program. Call or email us for more information.
One of the most overlooked tools in the toolbar of Probe 3 is the "Map Information Tool". The Map Information Tool is used to show specific elevation, field strength values, and geographic coordinates at the point where the crosshair is located.
The abilities of the Map Info Tool do not stop there however. If the user simply right-clicks on the Probe 3 map while the Map Info Tool is in use, additional features are revealed. The window below will appear when the tool has been selected and the right-click is used. We will explain the use for each of the options in the window below.
This function will show the user the field strength, distance from the transmitter, and azimuth in degrees in a separate window. This function operates differently for the different types of studies that Probe 3 calculates. In an FCC simply coverage contour study, the tool will read the distance and bearing but the field strength does not change from the value of the contour draw on the map. When using the extended information option with a single station Longley-Rice study, all choices; field strength, distance, and bearing, change as the Map Info Tool is moved over the map.
Possibly one of the most useful ways to use the extended information option is when you are engaged in an interference study. As the Map Info Tool is moved over the Probe interference map, the extended information window shows information for all stations identified by the program as interferers. When the Map Info Tool is moved over an area of interference, and the U/D ratio at the point is exceeded, the field strength of the interferer turns red in the extended information window.
Another excellent feature of the map information tool can be used when doing a "highest signal" study. If you want to find which station in an area has the highest field strength, but the Longley-Rice colors are indeterminate, check the box labeled "Sort by FS". Now which ever station has the highest field strength will automatically be moved to the top of the list.
"XMIT" refers to the reference station of the study. The red field strength numbers represent points of interference and the interferer's signal strength at the points.
The time delay information tool is only available if you have purchased the time delay (booster) module for Probe 3. Click Here for more information on the booster module. The time delay map tool is used to facilitate the process of determining what time delay settings are best to achieve synchronization. To access the tool, choose “Show Time Delay Info” to display the time delay information window. As the map information tool is moved around the map, the numbers on this window will update to those matching the current location of the cursor. A time delay for the release of each transmitter is included and is considered in the final “Time Difference” that is reported. Use the “Set” button to change the time delay for a given transmitter (if both delays are set to zero then the model displays both signals leaving the transmitters at exactly the same time). Note that the time delay for a specific transmitter can also be set on the “Info” tab of the transmitter properties window (however the map will not automatically redraw after changing the setting there). View the map below to see the Time Delay Map Tool at work:
The generate point report option allows the user to get specific information in a report style page format. An example of this report can be seen by clicking here.
There are two different ways to use this option. One is to simply move the Map Info Tool over the spot at which you would like to generate the report. Then right click and choose 'Generate Point Report'. This will bring up a window with the latitude and longitude of the point at which the user clicked (Window is seen below). The latitude and longitude can be changed if the user knows the specific set of coordinates he or she would like to have.
The second way to choose a location for the point reporting is to search for a street address. Click on the 'Find US street address' button on the 'Point Report' window (seen above). This will bring up another window for the user to type in the the street number, name and zip code (below). Then click the "Search" button on the next screen. Probe II will go out and search its street level database for the address entered. Once the street address has been found and OK on the 'US Street Address' window has been selected, the latitude and longitude for that address will be automatically entered into the 'Point Report' window. Street names must be matched exactly with census names for the location to be found.
To view the report, click 'Create Report', on the 'Point Report' window. The report can then be printed or saved for later use.Add a Custom Tick Mark: The custom tick mark feature works in a similar way to the Point Report. When the 'Add a Custom Tick Mark' is selected by right clicking on the map using the Map Info Tool. Probe II automatically imports the latitude and longitude where the Map Info Tool was located. The window seen here below is the window that will appear when this option is used.
As seen in the window above, the user can also choose a street address at which to place a tick mark by selecting the 'Find US Street Address' button. This part of the routine is the same as in the "Point Report" option. The map below has had a custom tick mark added by using the street address tool of the 'Add a Custom Tick Mark' option. (Can you find it?)
The 'Move Transmitter' option is only available for FCC coverage studies. This option allows the user to move the transmitter to the spot on the screen where the Map Info Tool is located. To do this, right-click where you would like to move the transmitter and go to the 'Move Transmitter' option. The 'Transmitter Properties' window will appear and show the latitude and longitude coordinates to which the transmitter will be moved. When "OK" is selected from the 'Transmitter Properties' window the transmitter will be moved to it's new location. There is no way to undo the move (except by deleting the transmitter token altogether), so make sure you have your original coordinates available if you would like to move the transmitter back to its original location. Top
V-Soft has released an update that now plots "block level" population centroids. In previous versions of the program only the "group block" centroids were plotted on the map. When population totals for contours were calculated, block level population was used. Now, the size of the centroid has been reduced making the block population centroids appear clearer. The centroid values can still be turned on and off from the map settings window. Also changed in this update is the location of where InterDLG looks for the block population files. Before, the program looked for all population files in the "Geofiles\CE" folder. Now, InterDLG looks for the block population files ("Geoinxcx.dat" & "Cx.dat") in the "Geofiles\CX" folder, just like FMCommander. If you have not purchased the block level population overlay for InterDLG and would like to add this option, email Adam Puls or call 319-266-8402.
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