Radio Site Display

What is it?

The Radio Site Display shows an aerial view of the Earth with overlays providing the locations of amateur radio beacons, amateur stations, Field Day sites and other information. The view is customised for each user, centred on the user's own location.

Overview


Getting Started

It might be worth printing these instructions so that you can easily follow them.

1. Install Google Earth

You need the latest version of Google Earth.

Versions of Google Earth are available for Windows (2000, XP, Vista), Mac and various flavours of Linux. All our testing has been done using Windows XP, but we see no reason for it not to run on the other supported platforms and welcome any feedback about this.

A minimum of a 500MHz Pentium 3 and a 128kbps Internet connection are advised by Google. However, for best results, a 2G+ Pentium and 512kbs connection are recommended.

2. Enter/Update your location details

You will need to enter your location details (latitude/longitude) into a database. For Oceania users (Australia, New Zealand), this database resides on the VK/ZL Logger site, generously provided and supported by Adam Maurer VK4CP. Note that even if you are already registered with this site, for best results you should still update your details with your precise latitude/longitude.

Newcomers will firstly need to register for the site. Note that registrations are restricted to radio amateurs with a valid callsign. Once you have registered, go the the Opinfo page (page tabs are along the bottom), click on Modify your Profile (link at the top of the page) and enter your latitude/longitude. Use the "Find" link on that page to get your precise location.

3. Get a generic Radio Site file to get you started

The Radio Site files are commonly known as KML files (KML is Google Earth's programming language). Click here to get a generic KML file

You should be directed to the following web page:

KML Download Page

The web site will attempt to offer the KML file for upload. However, if your browser security settings are high, the file may be blocked and a warning message displayed along the top of the page. If so, there is normally an option to allow you to override the security and download the file.

You should now be presented with the Download page:

IE File Download Page

Click on Open, and the file will be loaded by Google Earth.

In some cases (if you're using Firefox), you may instead be presented with a generic file download page:

Firefox File Download Page

In this case, you'll need to save the file to a location on your hard drive, then double-click on the file to have Google Earth load it.

4. Check that everything seems to be running

Google Earth should now be running and showing a view of Australia. You should have a Sidebar at the left (if not, click on View->Sidebar). In the Sidebar, there is a Places section that should look something like this:

Sidebar

Try clicking on one of the boxes (e.g. Beacons 2m). You should now see:

2m Beacon Page

(Note: You might have to pan/zoom the display to force Google Earth to do an initial update of the icons).

Try clicking on other entries in the sidebar menu.

You can pan and zoom around the map to give more detail. Try zooming right in on VK8ULR (which is not a real Amateur Station by the way!).

5. Get a Radio Site file customised for your own location

Set the display for only QTHs. Zoom in to your own QTH and then click on the icon for it. You should see something like:

QTH Window

If you don't see your latitude and longitude underlined (i.e. Mh Grid underlined instead), go back to step 2 and update your Opinfo details to include your latitude and longitude. You can also zoom right in on your QTH here to see if your location is spot on (sometime Google Earth can be a few 10's of metres out compared to Google Maps). If not, then use the cursor to find your exact location, and update your Opinfo entry accordingly.

Click on the link at the bottom of this pop-up window and you will create a new KML file for your own site, going through the same process as for the generic KML file described earlier. This KML file will be called [your callsign]_NL.kml (for the example above - VK3HZ_NL.kml).

You should save your customised KML setup in My Places in the Google Earth menu. You can do this by right-clicking on the "Bearings from [your callsign] to:" line in Temporary Places and selecting "Save To My Places". (You can delete the "Bearings from VK8ULR to:" entry). From then on, to get the Radio Site display, you only need to start Google Earth and select from the "Bearings from [your callsign] to:" options.

You can also create a custom KML file for any beacon or other site, creating a customised display centred on that site. For example, for Field Day sites, it could be useful to know beforehand what distances to other stations will be (useful for planning for a contest where scoring is based on distance) and what beam headings will be required.

In fact, you can customise the display for any site. Simply click on Radio Site KML Generator and you will be taken to a blank Google Earth link generator page where you can enter any site ID, latitude and longitude.

If you want to navigate to the site using Google Earth, use the Radio Site Finder Pan and zoom the Google Earth display to centre the white square on the point of interest and click on it. You will again get a page with a link to the Google Earth link generator page.


Hints and Tips

Screen Updating

The overlaid information is cropped to the currently viewed area, and is only updated when you zoom or pan the display with the "layer" (e.g. 2m beacons) active. If the layer is off when you zoom, the layer will retain its previous cropping and so may not appear correctly when the layer is again enabled. A zoom/pan will restore the view to its correct cropping.

Stations In The Middle Disappear As I Zoom Out

For the QTH display, in an attempt to reduce the screen update time, data usage and general clutter, when displaying larger areas, only the outermost QTH's will be shown. This may result in a blank hole in the middle, depending of the density of stations. Zooming back in will re-display the inner QTH's again.

Distance / Bearing Calculations

The distances and bearings are calculated using Vincenty's Formula. This is the most accurate method, and is used for Distance Record calculations in VK.

However, the calculation is only as accurate as the position information that is supplied. Many of the database locations are only given as 6-digit Maidenhead gridsquares, which could be in error by up to 9 km in longitude and 4.5 km in latitude. The Radio Site display will use the best information that is available. You can determine what information is being used by clicking on the icon for the site (see example for VK3HZ in Step 5 of Getting Started above). If the site has a latitude/longitude defined, this will be used and these fields will be underlined. Otherwise, the less accurate gridsquare (shown as Mh Grid) will be used and underlined.

Overlay Transparency Control

Some of the 3rd-party overlays draw solid colour areas over the Google Earth display, obscuring the images beneath. The transparency of an overlay can be adjusted. Click on the overlay selection in the Google Earth menu and adjust the slider control that appears at the bottom of the Places menu area to the left for greater transparency.

Shifty Icons

When you have multiple overlays enabled (e.g. 23cm beacons and QTH), there are actually multiple icons at the home location - one for each overlay and, in the case of the QTH overlay, one for your QTH too. You should see a label for each icon. However, Google Earth has its own way of managing these multiple overlays and often suppresses some of the labels to keep the display "clean". When you mouse over the home icon, it turns into a white circle and when you click on it, it will split into several white circles with short lines back to the home location. These circles represent each overlay, and if you click on one of them (e.g. [Your callsign] - Beacons 23cm) you'll get the information for that overlay (e.g. list of 23cm beacons in view). This multiple-icon-effect also happens when, for example, two beacons on different bands are co-located.

Multi Icons -> click -> Circle Icon

I've got two icons with my callsign in slightly different locations

This has probably happened after you've updated your location in the database. Your Home location (blue circle) is still at the old coordinates, while your "QTH" icon is at the new location. You need to generate a new KML file for Google Earth to pick up the new coordinates for the Home location. Make sure you click on the icon at your QTH, not the Home icon (with the blue circle around it) when generating the KML.

Field Day Sites

A future plan is to create a web page for entry of Field Day site details (photos, coordinates etc.) For the moment, these site locations are held in an internal database. If you would like a site to be added, please email me the site name and coordinates and I will update the database.


Other Overlays

Apart from showing the location of Radio Sites, this display can be used as the basis of a propagation analysis tool by adding overlays to the basic QTH display. These come in the form of KML files that need to be downloaded as you've already done with the Radio Site KML file. Some interesting examples are given below.

Aircraft

This will overlay aircraft positions, obtained by a network of ADS-B receivers, on the Google Earth display. You need a registered copy of PlanePlotter. Full instructions on setting this up may be found on the Plane Plotter and Radio Site Display page.

Tropo Propagation Prediction

Hepburn overlays the Hepburn Tropospheric Ducting Forecast page for Australia on the Google Earth display.

Auroral Activity

Aurora provides an Auroral Activity overlay, derived from data from the NOAA from the POES satellite. Note that you may get a minor error message about an image file not found. Ignore this.

Electron Content

The links below provide Electron Content overlays. However, the data seems to currently be US-centric:

Electron Content: E-Layer

Electron Content: F2-Layer

Electron Content: Total (TEC)


Acknowledgements

Thanks to Google for creating such an amazing - and free - resource as Google Earth. All rights acknowledged etc.

Thanks to John VK3ZJP who did most of the hard work for the Radio Site Display.

Thanks to Adam VK4CP for allowing the use of his VK/ZL Logger database and adding some requested enhancements.

Contact Information

I welcome any questions or feedback about the Radio Site Display. You can contact me at: [my callsign] at wia org au

David Smith VK3HZ