01/23/19 13:47:28 UTC
225.875 MHz
Couple of pilots talking
01/19/19 18:49:59 UTC
385.55 MHz
Lucky 21 heading to W-168 on ZMA Discrete
01/18/19 02:32:40 UTC
343.500 MHz
Refueler on AR16 Primary. “I’ll take your tail number”
01/17/19 15:12:39 UTC
343.000 MHz
Couple of pilots talking
01/15/19 13:32:19 UTC
339.500 MHz
Go for Defense 986 and another pilot in communications.

01/20/19 20:17:16 UTC
337.3000 MHz
E-4 Data Link
01/13/19 15:29:30 UTC
60.1000 MHz
Calling in strikes against ground targets at Avon Park
01/07/19 20:39:46 UTC
254.400 MHz
01/07/19 20:21:34 UTC
317.525 MHz
01/07/19 18:46:13 UTC
350.200 MHz
01/07/19 17:37:23 UTC
262.760 MHz
sells range
01/07/19 14:13:41 UTC
143.425 MHz
Night Watch Reporting System

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How to Make Use of ADS-B Mode-S Data

I recently conducted a poll of MilAir listeners asking them if they use mode=s data in their hobby. There were a few votes from people stating they weren't sure how to use mode-s data or what it was all about.

So I thought I'd write a short write-up on what it is and how I use it.

Mode-S data is the data transmitted from the aircraft's transponder on 1090 MHz. There are several different messages that the transponder can transmit. Depending on the message transmitted we can get some useful information such as aircrafts altitude and callsign. If we get enough messages containing altitude, we can then graph the various altitudes reported in the messages. With this graph you can make an educated guess as to what the plane is doing.

Example, if you first see him at 30,000' but 15 minutes later he's at 10,000' AND you have an airport in your general area you can guess he's landing. I see this a lot with E-4B's, either they're going through my coverage area level the entire time, or if he's descending its a good guess he's landing at Patrick AFB. Also I see a lot of tankers as they're climbing out of MacDill AFB, or tankers landing at MacDill.

When I see an E-4B you know its a good time to start checking out the ORDERWIRE freqs. If you see a tanker leveling off around 26,000' or so, that's a good time to start checking your AirRefueling frequencies. When you see an aircraft at an altitude and if you know which ARTCC freq is for that altitude (LOW, HIGH, or ULTRA-HIGH) you can usually find him on that centers frequency.

Other uses are when I see E-3's on mode-s its a good bet they're going to be supporting a military exercise, again its time to start checking activity on known freqs that fighters in your area use during exercises.

If you use my software with the Raspberry Pi computer (see Raspberry Pi / RTL Dongle Mode-S Sharing System), a graph will be generated of not only altitude, but signal strength from the 1090MHz transponders signal. If he's getting stronger generally that means he is flying towards you, weaker he is flying away.

If you live near water and you start seeing Coast Guard aircraft on your mode-s data AND you see them start flying low its a pretty good bet there's an SAR (Search & Rescue) mission happening in your area. Here are some USCG aircraft recently I captured on mode-s: USCG Helo SAR Mission This USCG Helo was involved in an SAR for a missing swimmer from the beach at Daytona Beach. When looking at the altitude graph you see he took off from KDAB after refueling, climbed to 700' to head to the beach where you see he descending to about 100' to fly the search pattern. This went on for 2 days with various USCG Helo's and a C-144

This is just some of the helpful info you can get from mode-s to better you're hobby experience. The more you look at the mode-s data for your area, you'll quickly start seeing patterns which can clue you in on what's happening and where to listen.

Not all, but most aircraft transmit mode-s data, in a few years it will be a requirement. At this time it is very rare to see military fighters on mode-s however it appears that most transports, tankers, the fleet of E-4B's, E-3's, and E-6's are all transmitting on mode-s. In the near future fighters will have to as well in order to make the "NextGen Air Traffic Control System" function.

The aircraft used for Air Foce One / Two as well as other government VIP's can be seen on mode-s. I've seen AF1/2 several times this year.

Another neat feature, if you start seeing RCHxxxT flights (REACH transports with callsigns ending in "T") on mode-s its very likely AF1/2 will be in your area in the next few days as REACHxxxT flights are the presidential advance transport aircraft.

So that is a short write-up on how I use mode-s to help in my listening experience.

If you want to see live mode-s data you can go here: Live Military Aircraft Mode-S Logger this page updates every 15 seconds. I hope to seen start having more mode-s stations feeding this webpage.

If you want get more info on how to receive mode-s data with some very cheap hardware check out the following pages:
Your Own $20 ADS-B Aircraft Radar System
Self-Contained Aircraft Radar System
Raspberry Pi / RTL Dongle Mode-S Sharing System

I hope you've enjoyed this article.