Editing VHF omnidirectional range (section)

===Service volumes===
A VOR station serves a volume of airspace called its Service Volume. Some VORs have a relatively small geographic area protected from interference by other stations on the same frequency—called "terminal" or T-VORs. Other stations may have protection out to {{convert|130|nmi|km|abbr=off}} or more. It is popularly thought that there is a standard difference in power output between T-VORs and other stations, but in fact the stations' power output is set to provide adequate signal strength in the specific site's service volume.

In the United States, there are three standard service volumes (SSV): terminal, low, and high (standard service volumes do not apply to published [[instrument flight rules]] (IFR) routes).<ref>FAA Aeronautical Information Manual 1-1-8 (c)</ref>

Additionally, two new service volumes&nbsp;– "VOR low" and "VOR high"&nbsp;– were added in 2021, providing expanded coverage above 5,000 feet AGL. This allows aircraft to continue to receive off-route VOR signals despite the reduced number of VOR ground stations provided by the VOR Minimum Operational Network.<ref>{{Cite web|date=2 December 2021|title=Aeronautical Information Manual §1-1-8(c)(2)|url=https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap1_section_1.html#aim0101.html.8|website=Federal Aviation Administration|access-date=13 January 2022|archive-date=2 January 2022|archive-url=https://web.archive.org/web/20220102143740/https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap1_section_1.html#aim0101.html.8|url-status=live}}</ref>

{| class="wikitable" summary="Table of standard service volume classes"
|+ US standard service volumes (from FAA AIM<ref name="Online AIM">{{cite web | author=Federal Aviation Administration | date=April 3, 2014 | url=https://www.faa.gov/air_traffic/publications/media/aim.pdf | title=Aeronautical Information Manual | publisher=FAA | access-date=Jun 29, 2015 | archive-date=December 2, 2017 | archive-url=https://web.archive.org/web/20171202184724/https://www.faa.gov/air_traffic/publications/media/aim.pdf | url-status=live }}</ref>)
|-
! SSV class designator !! Dimensions
|-
| T (terminal) || From 1,000 feet above ground level (AGL) up to and including 12,000 feet AGL at radial distances out to 25 NM.
|-
| L (low altitude) || From 1,000 feet AGL up to and including 18,000 feet AGL at radial distances out to 40 NM.
|-
| H (high altitude) || From 1,000 feet AGL up to and including 14,500 feet AGL at radial distances out to 40 NM. From 14,500 AGL up to and including 18,000 feet at radial distances out to 100&nbsp;NM. From 18,000 feet AGL up to and including 45,000 feet AGL at radial distances out to 130 NM. From 45,000 feet AGL up to and including 60,000 feet at radial distances out to 100 NM.
|-
|VL (VOR Low)
|From 1,000 feet ATH up to but not including 5,000 feet ATH at radial distances out to 40 NM. From 5,000 feet ATH up to but not including 18,000 feet ATH at radial distances out to 70 NM.
|-
|VH (VOR High)
|From 1,000 feet ATH up to but not including 5,000 feet ATH at radial distances out to 40 NM. From 5,000 feet ATH up to but not including 14,500 feet ATH at radial distances out to 70 NM. From 14,500 ATH up to and including 60,000 feet at radial distances out to 100 NM. From 18,000 feet ATH up to and including 45,000 feet ATH at radial distances out to 130 NM.
|}