Aircraft reception range

[BM82557]

I'm looking for info on the approximate range of reception of aircraft at increasing altitudes. Anyone know what the range would be at 10000', 20000', up to 40000' or is there a formula that can be used to figure it up?

Thanks

 

[nd5y]

The radio horizon formula is

d=SQRT(2h)

Where distance in miles (d) equals the suare root of 2x antenna hieight (h) in feet.

So an aircraft at 40,000 ft should be able to work stations on the ground 282 miles away.

Another book I have says d=1.415*SQRT(h)

 

[BM82557]

Thanks for the info!!

 

[SkipSanders]

Motorola's rule of thumb for reliable comms is range in miles = square root of antenna height in feet.

Do it twice, one for transmitting antenna, once for receiving antenna, and add them together.

Actual range may be anywhere from that out to twice as far, depending on obstructions.

All these are approximations, the real path depends on terrain in between, frequency and weather, etc.

Most A/C are below 10,000 feet, where oxygen support is desired. That would be 100-200 miles range. Unless you're sitting at the top of a mountain, your receiver antenna height isn't likely to add too much to this.

Sealed cabin pressurized aircraft may be operating as high as 30,000 - 37,000 feet, for 175-390 mile range. [edited]

Your local traffic is probably at 1000 to 5000 feet, for 30-60 miles at the low end, and 70-140 miles at the high end.

 

[BMT]

I checked the distaance on 2 of my hit's today.

Deltona,FL- Savannah GA 256 miles
Deltona,FL- Alma,GA 168 miles.

These are straight line distance from a aero chart.

None of my antenna's are over 25 feet.

BMT

 

[prcguy]

Most commercial aircraft are running 30,000 to 37,000 ft altitude unless their trip is under 500mi. You can get well over 300mi range to aircraft at these altitudes if there are no obstructions to your monitor antenna and some elevation (hill, mountain) will squeeze a little more distance. My personal record from an 800ft hill to an aircraft at 34,000ft over water was 338NM as read by the pilot who set my location as a waypoint, which is 388.96 statute miles! Aircraft was a Boeing 737 (20 to 40w?) and a 5w VHF hand held with 1/4 wavelength whip.
prcguy

Motorola's rule of thumb for reliable comms is range in miles = square root of antenna height in feet.

Do it twice, one for transmitting antenna, once for receiving antenna, and add them together.

Actual range may be anywhere from that out to twice as far, depending on obstructions.

All these are approximations, the real path depends on terrain in between, frequency and weather, etc.

Most A/C are below 10,000 feet, where oxygen support is desired. That would be 100-200 miles range. Unless you're sitting at the top of a mountain, your receiver antenna height isn't likely to add too much to this.

Even sealed cabin pressurized aircraft probably won't be operating above 25,000 feet, for 150-300 mile range.

Your local traffic is probably at 1000 to 5000 feet, for 30-60 miles at the low end, and 70-140 miles at the high end.

 

[prcguy]

I might add I tried to break the 300mi barrier from my home for years and could not due to surrounding terrain vs flight paths. It was only achieved with a coordinated flight to Hawaii and a hill top site above the ocean that faced HI.
prcguy

 

[EMD91123]

I live in a major metro area and my reception range from Altitudes SFC-10000 as around 50 miles,10000-24000 is 120-140, and from 24000-41000 is anywhere from 140-180 miles. I went up to High Mountain in NW JERSEY which has an elevation of 1800 feet above sea level and was getting around 300 miles range from 24000-37000 and low level wise about 200 miles. My antenna at home is mounted on my window air conditioner at about 10 feet above ground and my elevation is at 200 feet above sea level. For the gentleman in Deltona Fl thats quite good on that range. Should be interesting listening to traffic in Tampa when I move there since Florida is a pretty flat state.

 

[sflmonitor]

Another book I have says d=1.415*SQRT(h)

That is the formula that I've always used. It's pretty accurate. Here in South Florida it's easier to figure out distances due to our flat terrain.

 

[EMD91123]

How far do you get for range ???

 

[sflmonitor]

I can clearly hear aircraft at 30,000 ft (+/-) transiting Cuban airspace. That's over 250 miles from my location. I also hear military aircraft at various altitudes in the Avon Park area which is about 140 miles from me.

BTW, this is almost always monitored while I'm in my car.

 

[EMD91123]

My vacation spot will be in Fort Lauderdale and my Home will be in Tampa. For example what type of ranges would the forum think I will get from Flights say over 18000 feet ?

 

[sflmonitor]

It depends on what kind of receiving setup you will be using. As long as you have a good outdoor antenna and not surrounded by tall structures, you should get all-around great range here in Florida.

Like I mentioned earlier, I do most of my monitoring while driving. I am using a 396 with a Maxrad Mobile Scanner antenna with great results. It's not uncommon to hear planes on approach to Freeport Bahamas that are about 90 miles from me.

 

[EMD91123]

Cool sounds great. My setup is a basic radio shack radio with the magneticly mounted antenna hooked up and the centerally loaded antenna from the shack that is connected to either of my radios. Mostly it will be a handheld radio I will be monitoring from.

 

[EMD91123]

Lastly would you think from Tampa I will be able to recieve Fort Lauderdale/Miami traffic descending from 24000 to 16000 50 miles east of Ft Pierce ?

 

[BMT]

I have no problem monitoring the Miami RCAG on 281.5, probably 200 plus miles.

BMT

 

[EMD91123]

My main monitoring will be in the 118-136 Mhz. Range. Military doesn't really hit the spot with me.

 

[Turbo68]

I lve in Melbourne Australia and the main airport is 50 miles from where I live and I can hear the tower and surface movement control on a full signal strength and I live in flat area and I use an ICOM-AH7000 discone however I also got custom made antennas from RFI for the airband only which the civil aviation in australia use and I heard aircraft up to 1500 km away on a clean signal and I suppose it depends wher you live.I lived in a suburb befor which is about 5 km from wher I am now and i didnt even have to use any outdoor antennas at all and the reception was excellent and the strange thing was that i had power lines in the front off my house.

Regards Lino:ALINCO-DJX2000E,AOR-3000A,AOR-8200MK3,AOR-8600MK2,ICOM-R5,ICOM-R20,ICOM-PCR1000,ICOM-R2500,ICOM-R9000,ICOM-R9500,UNIDEN-245,UNIDEN-396,UNIDEN-780,UNIDEN-785E,UNIDEN-996,RADIO SHACK-PRO96,REALISTIC-PRO2035,YAESU-VX7R,YAESU-VR500,YAESU-VR5000.

 

[nycrich]

Here in Tampa with an active omnidirectional antenna( Dressler ARA500) at 5 feet I can hear 1. North- above FL230 traffic over into Goergia as far as Savannah.
2. East- above FL180 traffic over Melbourne, Cape , into the Atlantic going down
the east coast on Amber 699 & 700.
3. West- above FL200 you can hear Gulf of Mexico , Houston center traffic on 135.775
4. South- above FL280 you can hear Cuban ATC (123.7/120.25 ). At FL180 traffic
going into FLL & MIA.
It is very common to hear traffic on 128-132 company freqs calling for gate info, etc saying that they are 20mins out for FLL & MIA over the Tampa\Orlando airspace.
One important thing to remember is the direction the aircraft is flying. If they are landing on runways and coming in facing north more radio power is transmitted north and you will be able to hear traffic at lower altitudes. I noticed landing on runways East/West is harder to hear. The VHF radio transmitter on an aircraft is 200 Watts.
Most of the mornings here in Tampa there is a lot of skip and you will be able to hear ground stations from Houston, Jacksonville, and Miami.

Richard.
Tampa Bay, FL.

 

[sflmonitor]

The VHF radio transmitter on an aircraft is 200 Watts.

200 watts? I thought they transmitted between 5 - 50 watts.