Splat!

"Splat! is a program which utilizes terrain data (from Space Shuttle missions) to create plots for determining coverage areas provided by various antenna configurations, or to analyze the radio path between two locations. Splat! is of particular interest to the Amateur Radio Community. This web page provides a web interface to the splat! program."

Here are three miniature examples, click the 3rd image on the right to see a much larger plot of of VK7RAA.

With the plot in Google Earth you can zoom right in and see where your house is under the overlay, especially if you make it more transparent.

Here is a detail of VK7RAA's coverage in Launceston taken from the [large plot] on the right above..

Click the image or click [here] for a larger view. The level of detail is amazing.

Using Bill's splat engine I've registered and carried out Longley-Rice Path Loss Analysis plots for some Tasmanian sites.
Click a callsign to download a zip file containing the splat .jpg and the Google Earth .kml file to view them on your computer.

VK7RAA
VK7RAB
VK7RBH
VK7RNE
VK7RIN
VK7RWC
VK7JJ - our home at Weymouth
VK7FLYN - our bush block at Fingerpost Hill, just north of Launceston
VK7HAY - Hayden's new home
Millers Bluff

Splat! can also be used for phone towers, here is a zip file for the Telstra NextG tower on Abel's Hill (aka 7EX Hill):

Telstra Abel's Hill site

Open the .kml file in Google Earth

Each zip file contains a folder with the .jpg and .kml file.
- unzip the folder, but keep both the .jpg and .kml files together.
- double-clicking the .kml file should launch Google Earth and open the .jpg file as a semi-transparent overlay.
- if you are an experienced Google Earth user you will know how to adjust the transparency, save the file to Your Places and so on. :)

Useful links

[click] W5GFE's Splat! home page
[click] The registration page
[click] The line-of-site and path loss plot drawing page
[click] The path profiling page

Hints, tips and gotchas:

How to find a location's coordinates accurately using Google Maps (so you can register the location):
- open Google maps, eg. open this URL in your browser: http://maps.google.com
- search for the place you want to go to, eg. type Weymouth Tas in the search field and hit enter
- zoom in and view the location using terrain or satellite view to obtain the most accurate spot
- right mouse click at the spot and select "What's here?" from the popup menu
- you'll see the coordinates of that spot, eg. -41.013033,147.145407

Entering the coordinates for a new Splat registration:
- the Splat calculations do not seem to like any more than four decimal places; remember -147 is the longitude, -42 is the latitude
- both the longitude and latitude must have a minus sign in front of them
- make sure you select "Australia" every time from the popup region menu
- enter the height (in feet) of your antenna mast only; the program works out your ground height automatically
- if you need to make corrections, make sure you click the Update radio button or you will create a double entry
- enter your details carefully and methodically because there seems to be no way to remove double entries

Generating plots:
- sometimes the plots can take quite a while so be patient
- the plot jpg which the site generates only stays on the site for a few hours, so don't link to the plot urls
- you can download the plot jpg and kml file from the links on the page that first appears when your new plot is ready
- the colours on the plots represent specific signal levels and [here] is the legend.

Here is a plot of the path between VK7RBH and my station, with a summary report of the path loss:

Summary for the link between VK7JJ and VK7RBH:

Free space path loss: 122.43 dB
Longley-Rice path loss: 147.40 dB
Attenuation due to effects of terrain: 24.97 dB
Mode of propagation: Single Horizon, Diffraction Dominant