# Theoretical range of coverage
To judge the actual range, one needs to first know what kind of range is even possible for the station's location. 1090 MHz reception requires a direct line of sight through air to what you want to receive, thus depends on obstacles and the curvature of the earth. To get that theoretical range for a location, follow these steps.
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The first step can be done by anyone running either a BYOD station or an approved hardware station. The second step is specific to BYOD stations and cannot be done on an approved hardware station.
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#### **1: Create panorama and look at your outline on heywhatsthat.com**
* Visit
* Click "New Panorama" at the top
* For Step 1, set the location (via address or lat/lon) for your antenna precisely
* Skip step 2.
* For step 3 enter the height of the antenna for your install location, leave the radio button as "above ground".
* For step 4, enter a title and click Submit Request
* Wait for the request to finish and load a new page.
* Scroll down to the map and click the "Up in the Air" button on the top right of the map
* Change the "30000" value below the map to "40000" (this is maximum expected altitude of flights in your area).
* You can change the altitudes (ft) below the map to view different outlines for your location
* Those outlines tell you how far you can receive aircraft at the associated altitudes
* Zoom out a few times with the "-" (minus sign) on the map until you can see the theoretical coverage outlines.
* The panorama does not take into account obstacles closer to the antenna than approximately 100 ft, trees are also not considered but can block reception
#### **2: Integrate theoretical range outline into your local tar1090 display**
* On the top left of the page, an URL to revisit the panorama is mentioned. It will look something like:\
\*\*
* Replace the XXXXX in the following command with the value after view= in your panorama URL, then run the command on your pi:
```
sudo /usr/local/share/tar1090/getupintheair.sh XXXXX
```
* You should now have a range outline for the theoretical range for aircraft at 40000 ft on your tar1090 map
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If you wish to turn the outline off or on in tar1090, use the Legend/Layers button on the top of tar1090 screen and select/unselect the "terrain-based range outline" checkbox.
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