8 ):ADD TERRAIN LIMIT RINGS (OPTIONAL)
Dump1090-fa can display terrain limit rings using data obtained from the website http://www.heywhatsthat.com .
(a) First you have to generate a panorama for your location. To do this, follow the steps in first post of the following thread:
What is the Maximum Range I can Get?
(b) Once your panorama is generated, look near the top left of your newly created panorama page. You will see URL of your panorama there. The URL will be http: // www . heywhatsthat . com/?view=XXXXXXXX where XXXXXXXX is the ID for your panorama.
See screenshot below.
( c ) Use following command to download the generated panorama’s JSON file “upintheair.json” to your RPi, and save it in the folder “/usr/share/dump1090-fa/html” (replace XXXXXXXX in the command below by your panorama’s ID).
sudo wget -O /usr/share/dump1090-fa/html/upintheair.json "http://www.heywhatsthat.com/api/upintheair.json?id=XXXXXXXX&refraction=0.25&alts=3048,12192"
You can create as many rings as you want by adding elevations (in meters) at the end of URL given in the wget command above after “&alts=”, separated by commas.
10,000 ft = 3048 m
20,000 ft = 6096 m
25,000 ft = 7620 m
30,000 ft = 9144 m
40,000 ft = 12192 m
Hence if you want to add all the 5 elevation rings noted above, the string at the end of wget URL will become “&alts=3048,6096,7620,9144,12192”
To keep map un-cluttered, I have used only 2 rings in the wget command above. i.e. the 10,000 feet (3048 meters), and 40,000 feet (12192 meters).
Important:
Use altitude in meters in the wget URL above.
Do NOT use feet.
(d) Reload your browser. Clear browser cache if necessary
