Aerial VASCAR Countermeasure Discussion (Zaon MRX, ADS-B, etc)

Discussion in 'Passive Countermeasures' started by GoDuke, Jan 1, 2013.

  1. GoDuke

    GoDuke Mr Breeze Advanced User Premium Member

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    As we all try to figure out contermeasures to what LEO’s may use in speed traps, there is a desire to figure out when planes are being used for VASCAR. While aerial VASCAR is (in my opinion), less cost effective than a trooper sitting at an onramp, LEO’s still seem to use this method, so after consultation with protias, we thought it would be helpful to have a thread discussing countermeasure options. Primarily my information below stems from my general aviation knowledge of collision avoidance systems.

    As you can imagine, in a small plane, collisions with other aircraft are like shark attacks for swimmers – they’re rare but always in the back of your minds. As such, there is a fair amount of time, energy, and money devoted to figuring out where other aircraft are. Here are some of the ways pilots (and potentially you) can be made aware of other aircraft. Some of this stuff I may take for granted so if anything needs further clarification, let me know. As I get feedback from folks, I will revise and update this. Also, if this is too long, let me know and I’ll try to condense it.

    Old Fashioned Transponders – Most aircraft are required to have a transponder which identifies the plane’s position and aircraft tail number to ATC (Air Traffic Control). Further, operating within the airspace of moderately busy airports (Raleigh-Durham, Greensboro-Spartanburg, etc) or within 30 nautical miles of the big boys (Atlanta, New York, etc), the transponder needs to report altitude as well. Transponders work by responding to interrogations from ATC facilities. Essentially, ATC sends out a ping that says “who’s there” and transponders of aircraft within range respond with “I am” in the form of a 4 digit squawk code and depending on requirements, an altitude. This Squawk code is given to the pilot by ATC and the pilot manually sets the code into the transponder. The actual code is irrelevant for our purposes here.

    Zaon has developed several devices they call PCAS (portable collision avoidance system) devices to listen for these transponder replies. Depending on the model you have, they will tell you the relative altitude and distance of other aircraft. The MRX will give you the distance and relative altitude of the nearest plane. The XRX will track several planes and give you positional information as well and will track the 3 nearest planes. Note, these typically only have a reporting range of a couple miles but that should be sufficient for VASCAR.

    I have one of these devices (XRX) I use when I fly and while they do increase situational awareness, I have found them to be a bit imperfect. First, I have gotten falses before which scared the living daylights out of me (for instance, reporting a plane at 0miles distance and 300 feet below me). Second, this device will pick up any aircraft’s transponder and there are a lot of planes out there, compounded by the fact that there are a lot of small airports near interstates where you will likely be operating. This consideration can be countered by also looking for nearby VASCAR lines, but your PCAS device may be chattier than you’d like.

    Finally, and potentially most importantly, for this device to indicate a plane, their transponder needs to be functioning and has to be within interrogation range of an ATC facility. In some mountainous places, or even flying at low elevation it is possible to be out of range of an ATC facility so you may not pickup operations in those areas/conditions.

    As an alternative to PCAS, better equipped planes use TCAS (Traffic Collision Avoidance System), but that requires you have a transponder that will receive traffic information from ATC and I don’t think they’d be too happy about people running those in cars and I doubt it’s legal. Plus, they are very expensive and you’d need an aviation GPS that can translate that data into something visually usable. Aviation GPS’ are also very expensive.

    PCAS Pros: Portable, Cost Effective (relatively), Should alert in most cases, Active Alerting (will alert you if there is a plane nearby)
    PCAS Cons: Potential for falses, No ability to verify a bogey, Coverage issues create potential no-alert situations

    ADS-B – The current methodology for identifying and disseminating aircraft locations is pretty outdated and imprecise. As part of the FAA’s NextGen ATC platform, they have developed the ADS-B platform (Automatic Dependent Surveillance-Broadcast). Essentially, rather than working off of radar, this platform requires that planes broadcast their GPS position and altitude which ATC then uses to determine everybody’s position. When an ADS-B equipped ATC receiver gets an ADS-B transmission from a plane, it then responds with traffic information on all traffic it knows of within 30nm of the plane in question. Additionally, each ADS-B location will also broadcast weather information (very important for pilots)

    Now, there are ADS-B receivers for sale. Primarily, these exist to provide in-cockpit weather without the need for an XM weather subscription. Some offer the additional capablity of receiving ADS-B traffic information. Some systems come complete, but most are designed to feed into an iPad aviation app or an aviation GPS. They will then display the traffic information on a moving map centered around you.

    But here’s the catch – As stated above, ATC only transmits traffic information within 30nm of a plane transmitting ADS-B. So, if you’re driving and there are no ADS-B equipped planes within 30nm of you, you will get no information. If there are ADS-B planes within 30nm, you will only get info on planes within 30nm of THEM. The deadline for ADS-B compliance is currently 2020 and there are rumors that the deadline will be extended as these systems can be expensive to implement. Needless to say, most smaller aircraft do no currently have ADS-B transmitters.

    A further disadvantage is that your receiver will be listening for ground-based transmissions that are not meant to be received by ground sources, which creates the potential for reception issues if you’re behind a mountain, hill, etc.

    ADS-B Receiver Pros: More Robust than PCAS
    ADS-B Receiver Cons: Expensive, Coverage/Compliance gaps, Will not provide info if no compliant aircraft nearby

    Other Options
    The primary function of the devices listed above is to assist in mid-air collision avoidance. Therefore, the main function is to let planes know what other planes are nearby and that might pose a threat. The information below is more geared towards generally knowing what planes are out there.

    Web/App Flight Trackers: One intriguing option is to use some sort of app or web-based software that reports plane positions as it will probably be far more cost effective than buying a separate piece of equipment. One app I found with a BRIEF google search that uses ADS-B data is http://planefinder.net. I’m sure there are other options out there such as FlightAware but I haven’t fully investigated these. I also don’t know how frequently these apps refresh the traffic data. Presumably, some apps can lookup ownership info of operating planes so you can see if it’s owned by a law enforcement agency.

    However, these would all require somebody to be watching the map to see what aircraft are nearby and the screen may be saturated with irrelevant traffic (do you really care if a US Air flight at 30,000 feet is above you?). Perhaps an enterprising programmer could design an app that filters out traffic above a certain altitude and those that are on flight plans to a specific destination

    Web/App Pros: Very Cost Effective, Should alleviate ADS-B reception issues,
    Web/App Cons: Reliability of app data, Refresh frequency unknown, May report too many aircraft, Requires monitoring - will not actively alert

    Scanners: Safe VFR (visual flight rules) usually requires pretty diligent communication to let other planes know what you’re doing and where you are. Presumably a plane running VASCAR should periodically broadcast its location and its current flight actions (maneuvering or circling over a specific location). To check for nearby planes, you could listen to the frequencies of nearby airports but that requires a lot of frequency monitoring and probably isn't practical. As Ersin noted, you could also listen for communication with LEO's on the ground. IF VASCAR is prevalent in your area, listening on LEO frequencies is probably not a bad idea irrespective of if its ground or aerial VASCAR you're worried about.

    Eyeballs - You could always try to look for planes, but small planes are VERY hard to see, even when you know where to look. Nighttime is probably the easiest as you can look for the beacon or strobe lights, but I imagine they can’t run VASCAR at night since they can’t identify specific cars.

    Conclusion: In the end, a PCAS type system may provide the most reliable method of reporting nearby aircraft, but be aware it is not foolproof and nothing is a good substitute for an eagle-eyed driver paying attention.

    FEEDBACK WELCOME!!!
     
    Last edited: Jan 2, 2013
  2. THX1138

    THX1138 Premium Member Advanced User Premium Member

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    You might correct this statement.....

    "Essentially, ATC sends out a ping that says “who’s there” and transponders of aircraft within range respond with “I am” in the form of a tail number such as N736RW and depending on requirements, an altitude."

    ""Essentially, ATC sends out a ping that says “who’s there” and transponders of aircraft within range respond with “I am” in the form of a 4 digit squawk code and depending on requirements, an altitude. This Squawk code is given to the pilot by ATC and the pilot manually sets the code into the transponder."
     
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  3. GoDuke

    GoDuke Mr Breeze Advanced User Premium Member

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    Ahh, yes. I don't know what I was thinking! I was a bit hungover.... Thanks
     
  4. ersin

    ersin Premium Member Advanced User Premium Member

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    I suppose if the LEO aircraft were near an airport you could listen to CTAF, Unicom or the tower frequency to hear position reports. (You can find these frequencies in the A/FD -- Airport Facility Directory -- and on sectional charts.) Perhaps they filed a flight plan in which case I would expect them to communicate with FSS, at least once in a while. But I wouldn't expect the aircraft to report its position to ATC (or to broadcast it) if its not near an airport.

    However, what about the communications to the LEOs on the ground? I'm assuming they would use a normal LEO frequency and so listening to this should provide some alert. OTOH, there is probably a dedicated frequency for this as there is in MD for the state police helicopter. (AFAIK, they don't use the helicopter anymore for traffic enforcement.) I think you'd get more success with a scanner monitoring the general LEO frequencies and especially a dedicated air-to-ground frequency if available.

    Otherwise, useful info. Thanks.


    Cheers,

    Ersin
     
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  5. NYSpeederPVM

    NYSpeederPVM Not So Perma-Beginner Intermediate User Premium Member

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    What about simply adding vascar line locations to the escort defender database/waze/live etc? It seems that they have to announce where the lines are with signs anyway.
     
  6. THX1138

    THX1138 Premium Member Advanced User Premium Member

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    Its possible, but there are a lot of lines. Not sure you'd want to slow down for every potential airplane trap considering most of the time they are not being monitored. If aerial enforcement is used in your area, I would strongly suggest getting the airplane detector. Its highly effective.
     
  7. Vortex

    Vortex Making Videos Administrator Advanced User Premium Member

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    Thank you for the detailed explanation regarding the technology and how it works!

    The best price I've found online for the PCAS MRX is $439 shipped to the US here: http://www.marvgolden.com/zaon-flight-systems-pcas-mrx.html (I don't know anything about the store and have no affiliation with them.)

    I wonder how often you'll see this alerting in practice. I know it all depends on where you drive, but I'm curious how easily we can tell if a plane is running VASCAR vs. when it's just a false.

    There's street signs and the typical lines on the road, but how often do you guys see this alerting to nearby planes that are just normal planes in the air?

    I wouldn't want to keep ignoring it if it's constantly "falsing", so to speak.
     
  8. switch626

    switch626 Scofflaw Advanced User Premium Member

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    Thank you GoDuke for a truly awesome thread on a topic that is so important to so many of us. This is a great thread, and I'm glad to see it stickied.

    I can add a couple of thoughts for your consideration too:

    First off, to my knowledge, the transponder will respond both to ATC AND to other transponders' interrogation signals. When my TPAS receives these signals, it also indicates whether the interrogation is coming from ATC (with a down arrow pointing to the ground) or to another aircraft (with an up arrow). Therefore it is possible to pick up a signal in the absence of ATC signals so long as there is other traffic around. Still, that frequency can be blocked by obstructions, so there is a potential for failure there.

    For those who do not wish to pony up for the PCAS or other higher end devices, you can sometimes find an obsolete Surecheck TPAS on Ebay for under $100 (mine was 80). There is a tradeoff though, the TPAS is bulky and may take a little creativity to mount. Many are turned off by that. You can also remote mount the antenna using a GPS cable and patch the audio into the stereo aux jack if you want to hear voice alerts. Just a few tips for the more frugal among us.

    As has been mentioned, the line locations can be added to the defender database, and here in FL and for the entire lenght of I-95, they are in the Cheetah Trinity database. My Cheetah C50 alerts to many of the line locations. If this doesn't drive you nuts, it can serve as a heads up to check your TPAS/PCAS for aircraft.

    The falses aren't as big of an issue as one might think. Once you get in the habit of ignoring the alert unless you see the lines, it's pretty easy to deal with. In some states and some situations, there may not be lines, so you cannot use that method safely (CA comes to mind).

    In addition to scanners, CB radios and apps like Waze and Trapster can be very helpful. Truckers will often go on and on about the bear in the air, and I suspect in some situations, you sould find the LEOs marked up ahead in Waze while you are just entering the trap. As will all CMs, each of these can fail in some way. Because of this, redundancy is key (as always)

    Sorry for going on like that. This is one of my favorite topics. Again, thanke for the awesome thread!
     
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  9. protias

    protias Retired CM enthusiast Advanced User Premium Member

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    I do have a Zaon MRX and have noticed a couple of times when I can see the aircraft 500-1000' off the deck but not alert me. Why is that?
     
  10. hazmat780

    hazmat780 Respect All - Fear None Intermediate User Premium Member

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    The secret police operating under the patriot act? Nah... nevermind. :p

    (via Mobile)
     
  11. GoDuke

    GoDuke Mr Breeze Advanced User Premium Member

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    They may not be high enough to be interrogated by ATC. I fly occasionally in a plane that has TCAS and it often tells me "traffic not available" around 500 AGL. And I'm flying out of airports within 30nm of CLT, which obviously is a major ATC facility. Add in some hills and it's possible they're in a radio shadow.

    Or they may not have their transponder turned on. It's a checklist item to do and it wouldn't surprise me greatly if somebody forgot on takeoff or switched it off as they were landing (they're not supposed to until they're on the ground).

    ---------- Post added at 10:17 AM ---------- Previous post was at 10:03 AM ----------

    I tend to order most of my gear from Sporty's Pilot Shop at sportys.com because they have a good return policy and 1-year satisfaction guarantee. Plus they ship quick so my instant gratification fix is met :). You may be able to get them to match Marv Golden's price if you call them and ask. Not sure.
     
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  12. Vortex

    Vortex Making Videos Administrator Advanced User Premium Member

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    You're right. They do price match, and that one-year guarantee is pretty awesome.

    Getting a great price is nice, but I also like to support companies with awesome customer service. Thanks for the recommendation. :)

    By the way, here's a copy of the Zaos PCAS MRX manual for reference. Lots of good info in here.

    View attachment MRX Manual v9.26.11b.pdf
     
  13. NYSpeederPVM

    NYSpeederPVM Not So Perma-Beginner Intermediate User Premium Member

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    Yeah that sounds reasonable, I don't have to worry about aerial vascar very much as they stopped doing it in ny as far as I know, and in my experience the locations that they used to use are few and far between so it wouldn't be a big deal to slow down for all of them, but it seems a place like Florida where they use a lot of it may be a different story.
     
  14. Vortex

    Vortex Making Videos Administrator Advanced User Premium Member

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    Doing a little research, I found some nice examples of aircraft speed enforcement being run here in WA.

    http://youtu.be/-nlqsx61JCs

    Here's a view from the skies:

    http://youtu.be/PllGER7tTcM

    and while we're on the topic of the PCAS MRX, here's a sample of it in action doing what it's designed to do in an airplane. Makes understanding it very easy. :)

    http://youtu.be/J4aYwTTL2eM

    A scanner looks like a great tool to use alongside a PCAS, but even on its own, if aircraft enforcement is used in your area, the unit looks to be very handy.

    SteadySpeeding has some great videos of it in action, used as a CM.
     
  15. TurboDriver

    TurboDriver PSL + 50, every now and then Advanced User Premium Member

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    Not all planes have a transponder and do not need it if they fly in certain types of airspace (type D, E or G). Plus if they are older or smaller and slower, and have limited avionics they might not have one. Also if it hasn't been certified in its last 24 months it cannot be used legally but the plane can still fly. There are getting to be a lot of new certified sport pilot planes that can fly slower and efficiently. It seems to me that aviation VASCAR is an expensive form of speed control and many tickets would have to be written to make it profitable.
     
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  16. GoDuke

    GoDuke Mr Breeze Advanced User Premium Member

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    For those that are in the area and want to learn more about ADS-B. the FAA is having a seminar on 2/2 in Spartanburg. Recognize that this will be all about its use for aviation, including weather. You have to register but it's open to the public I do believe

    http://www.faasafety.gov/SPANS/event_details.aspx?eid=47945

    Description "If you want to get more out of your avionics, including iPad, this is a chance to better understand the capabilities of this FREE service, including in-cockpit weather and traffic. ATP, CFII and FAASTeam Rep Adam Lockamy will also answer common questions about ADS-B. Questions such as: "What is ADS-B? What can it do for me as a pilot?" Don't miss this one! This seminar is for YOU!!!
     
  17. Blackhawks

    Blackhawks Learning to Fly Beginner User

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    Nice thread guys!

    Switch - Do you know if the Cheetah C50 has VASCAR data for most states in the USA? What about Canada?
     
  18. switch626

    switch626 Scofflaw Advanced User Premium Member

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    I don't really know how comprehensive the database is outside of FL. In fact, most of what is in the database in FL about VASCAR was reported to Cheetah by Thx1138 and myself. I also reported i-95 from end to end and everything I could find in VA. Hopefully others have been updating, I have no idea if they have though.

    Your area isn't in the database, you could always report it yourself. Better yet, get some people to help if you can. All you need Google maps to find the lines and get coordinates, then paste them into a spreadsheet and email them to cheetah. They will be happy to add your information to the database. We really should be doing this for FL again too.
     
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  19. Blackhawks

    Blackhawks Learning to Fly Beginner User

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    OK, thanks switch!

    The police in Alberta have advertised they will be using aerial enforcement this year much more than previous years. I belive there is several stretches that run from Calgary to Edmonton so the next time I do that trip I'll grab the coordinates and send to Cheetah.
     
  20. bhrodeoaz

    bhrodeoaz Mopar or no car.. wait i have a truck lol Advanced User Premium Member

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    as a ham radio operator, there are a few websites that list frequencies of local, county and state air agencies--problem is trying to decipher which one in particular is used for VASCAR as air support plays multi-role. Moreover some states like CA have aircraft dedicated to VASCAR enforcement. but there are some HAM radios like the one I have an ICOM T7h that I have programmed with those particular frequencies for air support-- on UHF,VHF-- just my 2 cents
     

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