Question: Does ADSB pick up Mode C

AKBill

AKBill

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AKBill
I fly SE Alaska and ADSB is not required or will not be because of the airspace. I have decided to put off ADSB installation as long as possible due to the cost. Can or does the ADSB system pick up mode C transponders?
 
IIRC, the ground stations uplink mode C targets.
 
GeorgeC said:
IIRC, the ground stations uplink mode C targets.
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Pretty sure this is the correct answer. I have a mode c transponder and a stratus, I frequently see my own airplane right on top of me in the traffic display.
 
You will get Mode A/C/S targets as the TIS-B ground station feed, but only reliably if you are ADS-b out. You may be able to receive some of the TIS-b messages being sent to other participating aircraft, but this won't be the whole picture for you. None of the ADS-b in solutions that I am aware of can receive actual Mode A/C/S and display them. All of these will receive 1090/978/TIS-b only.
 
vontresc said:
None of the ADS-b in solutions that I am aware of can receive actual Mode A/C/S and display them. All of these will receive 1090/978/TIS-b only.
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Thanks just wondering if I will be seen by ADSB-in equipped aircraft.
 
AKBill said:
Thanks just wondering if I will be seen by ADSB-in equipped aircraft.
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Kinda. They will reliably see you under the following conditions.
  1. The FAA radars that feed into the TIS-b systems see you
  2. They are in view of a ground station
  3. They are ADS-b out AND you are in the hockey puck (30mn diameter +-3500')
  4. Their ADS-b out is configured properly
  5. They happen to look out of the ******** window :D
Simple, right? REMEMBER Stratus/Stratux/Scout does not show all available traffic reliably unless you are ADS-b out.
 
vontresc said:
Kinda. They will reliably see you under the following conditions.
  1. The FAA radars that feed into the TIS-b systems see you
  2. They are in view of a ground station
  3. They are ADS-b out AND you are in the hockey puck (30mn diameter +-3500')
  4. Their ADS-b out is configured properly
  5. They happen to look out of the ******** window :D
Simple, right? REMEMBER Stratus/Stratux/Scout does not show all available traffic reliably unless you are ADS-b out.
Click to expand...
Well SE Alaska does not have radar as I know of and no ground stations that I know of either. 50% of my flights are below 3500' due to cloud cover. Is there a cheap non certified ADSB out that would allow others to view me as a target. Most everyone in SE Alaska gives position reports on 122.9 when traveling in high traffic areas.
 
Sorry. No "cheap" solution. There is that garmin UAT box that plugs in inline with your existing transponder for $1700. King/Trig have pin compatible 1090es solutions for around $2100-$2500. Those numbers are without install though
 
Bill, I've had this conversation with friends. Guys recite what they've read but it isn't necessarily correct. A friend has an Appareo ES transponder and a Stratus 2s. He describes flying low through passes in the Alaska Range, definitely outside of radar coverage, and he had his wingman's Cub show up the whole time even though that Cub has an old Mode C and nothing else. Nobody has an explanation but it's been repeated.
 
AKBill said:
I fly SE Alaska and ADSB is not required or will not be because of the airspace. I have decided to put off ADSB installation as long as possible due to the cost. Can or does the ADSB system pick up mode C transponders?
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Hey Bill,

Juneau Tower will see your Mode C most of the time. Just ask them if they see it. They do lose that capability sometimes due to weather caused outages. ANC Center on the other hand will not see you below about 10k ft without ADS-B out. All of our IFR aircraft are ADS-B equipped. Nonetheless, without a dedicated approach control, Juneau is one in, one out when it comes to IFR traffic.
 
In addition to ground radar, I think a TCAS interrogation will do it to.

vontresc said:
Kinda. They will reliably see you under the following conditions.
  1. The FAA radars that feed into the TIS-b systems see you
  2. They are in view of a ground station
  3. They are ADS-b out AND you are in the hockey puck (30mn diameter +-3500')
  4. Their ADS-b out is configured properly
  5. They happen to look out of the ******** window :D
Simple, right? REMEMBER Stratus/Stratux/Scout does not show all available traffic reliably unless you are ADS-b out.
Click to expand...
 
JohnAJohnson said:
In addition to ground radar, I think a TCAS interrogation will do it to.
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It will trigger the Mode-C reply, but a ground based SSR still needs to hear you so you can see it on the TIS-B. There are a number of traffic solutions that will display Mode-C/S traffic with direction and range info.
 
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