Military GPS hijinks

[rfinch]

Originally Posted by splevy

I'm just hoping someone in authority has considered the problem.

Someone has, they're called Europeans (http://en.wikipedia.org/wiki/Galileo_positioning_system).
I don't see how the FAA can say GPS is the future navigation system for the National Airspace when the military can play these hijinks at will.

[Ron Lee]

It probably would also be affected by such activities. Do note that these events are NOTAMed so it is not correct to blame the DoD. I doubt that the DoD will ever "turn off" GPS.

Plus there is no guarantee that Galileo will ever be built. From the beginning, it has suffered from an unrealistic cost-benefit argument.

[robertb328]

Last year I was flying adjacent to a "hot" restricted area according to ATC. My GPS went out so I turned on my VORs. They were both off by at least 60degrees and it took me some time to figure out what the problem was. I was fairly familiar with area and continued to my desstination using old fashioned pilotage. I was wondering if I was being watched to see how I would react. It would certianly be a good way to throw off 9-11 hijackers who were searching for a target. I am gald they have that capability.

[breister]

You youngsters are all spoiled - no piece of equipment can or should take the place of pilotage, situational awareness, or preparedness to navigate partial panel.

Reminds me of the cold war days in Germany. Flying at night, suddenly a controller whose voice you recognized from years of training flights would say, "Mako flight, vector 090 for separation." Of course, if you weren't paying attention to the fact that you were on the East German border you would just follow the instructions and be the focus of an international incident - not to mention getting your arse chewed for being an idiot.

Bottom line - know your systems and your flight plan and have a backup plan.

Oh, and stop whining that the folks who keep you safe run exercises to keep our boys prepared for anything!

[ajay]

Ron,

I'm a radar engineer, you'd think I'd be in favor of more radars, but the fact is gps can provide 10-100x more accurate positioning and at a significantly reduced cost to the government (I should say reduced cost to the FAA, the gps constellation is VERY expensive, but it is free as far as FAA is concerned). This accuracy clearly equates to improved collision avoidance safety and the Capstone project provided solid evidence. I'm sorry, but your arguments fall short. I'm not in favor of any govt mandate, but the technology/cost decision to transition to ADS-B is very difficult to argue against.

You can argue that we will likely be burdened with the cost of the new transponders and yes GDL 90's are $7k today, but if you want to hold out until the mandate in 2020 they will be less than mode C transponders today. They should be cheaper, there is nothing more than the technology in a cell phone. Moreover you'll see all the EFIS manufactures incorporate the ADS-B In functionality currently supported by Chelton and Garmin. And why will aviators want it? Because it will provide by far the best possible traffic awareness and real time weather and at a very low cost.

Yes gps is easy to jam, but so is radar (and VORs). How long to you think the western ranges will be allowed to test open jamming when an airliner dependent upon gps navigation and situational awareness is found crashed because of a DoD test? Didn't they use to test atomic bombs out there a few years back? Wonder why they stopped (at least above ground)?

ajay

Originally Posted by Ron Lee

Good points and I am vehemently opposed to the ADS-B Out NPRM.

My (still in work) response to that NPRM is here:

http://tinyurl.com/2wem8j

It may be costly with minimal to no benefit to most GA pilots. The FAA needs MORE primary radars...not less.

[Loboflyer]

Originally Posted by ajay

Ron,

I'm a radar engineer,

Preaching to the choir. But I believe a secondary means of navigation is just smart thinking. Pilotage isn't an option to the IFR pilot as a backup.

Yes gps is easy to jam, but so is radar (and VORs). How long to you think the western ranges will be allowed to test open jamming when an airliner dependent upon gps navigation and situational awareness is found crashed because of a DoD test? Didn't they use to test atomic bombs out there a few years back? Wonder why they stopped (at least above ground)?
ajay

The GPS tests are usually NOTAM'd and as was pointed out, very large radius.

GPS has its share of issues, but the worst is yet to come. The predictions are that during the peak of the sunspot cycle in a few years will make GPS useless. What exactly will happen? We don't know as we didn't have such widespread use of GPS during the last cycle peak. They are, however, planning to add additional frequencies for civilian use and atmospheric correction, so perhaps there will be at least one usable channel during atmospheric events.

And for the record, there was only one nuke explosion at WSMR... the first.

[Ron Lee]

If you do both and you are objective most likely you will agree with me.

I do not need 10x better position accuracy for flight following collision avoidance. It is not needed.

Capstone (Southeast Alaska) cannot be translated to the lower 48 in terms of safety improvement. Just can't.

The ADS-B Out NPRM offers little to no benefit to most GA pilots. Read the available documentation. You can't show a viable benefit to me. It is not there.

I do know that replacing primary radars with secondary (SSR) radars will reduce safety. I saw that on a recent trip from back east.

Your assertion that the ADS-B Out equipmennt will be less than transponders has zero credibility. Plus you will still need Mode C transponder functionality as backup.

[ajay]

Ron,

You tell me, which you would rather have

1. a ground based radar picture that can have errors of 100-1000 meters with the added delay of a controller telling you what sector the traffic is headed/coming - adding miles of more error and add to that the time delay error of reporting.

or

2. an accurate real time depiction of surrounding traffic on your moving map precise to 10s of meters

Do you really believe this accuracy (2) doesn't equate to improved safety? This has much more potential benefit in congested areas like the east coast than Alaska.

The requirement is only for ADS-B out, but the faa is smart enough to realize that aviators are going to want the benefit and get ADS-B in functionality.

Mode C will only be required during the transition period, the ADS-B message will incorporate your unique id and N #, ADS-B is a transponder too, there will be no need to have both. Unfortunately Big Brother will know exactly who and where you are, I'm not too happy about that.

The bad news is it is only a matter of time before Big Brother is going to require them in our cars and shortly after that an implant in our bodies. So if your smoke screen argument is for libertarian reasons I'm with you, but unfortunately the science is on there side on this one.

ajay

Originally Posted by Ron Lee

If you do both and you are objective most likely you will agree with me.

I do not need 10x better position accuracy for flight following collision avoidance. It is not needed.

Capstone (Southeast Alaska) cannot be translated to the lower 48 in terms of safety improvement. Just can't.

The ADS-B Out NPRM offers little to no benefit to most GA pilots. Read the available documentation. You can't show a viable benefit to me. It is not there.

I do know that replacing primary radars with secondary (SSR) radars will reduce safety. I saw that on a recent trip from back east.

Your assertion that the ADS-B Out equipmennt will be less than transponders has zero credibility. Plus you will still need Mode C transponder functionality as backup.

[PaigeHoffart]

Thread drift...

I'd think homeland defense would be reason enough to keep primary radars. I also like it when approach points out targets without transponders. Cubs, crop dusters, and large flocks of birds show up on primary radar.

10M accuracy? Who needs that type of accuracy for traffic avoidance? Now if you're an airliner doing an ILS on 17C with someone else doing simultaneous approaches on 17L and 17R at a large hub, maybe. That doesn't mean that we need to equip the whole fleet. ADS-B would also be great for remote or oceanic areas but we already have a system for that called TCAS.

Another thing to consider is failure modes (besides the GPS constellation). What happens when your ADS-B box fails? At least we have a few layers of redundancy now (Primary radar, SSR, overlapping coverage)

Paige

[ajay]

Paige,

I like your arguments and kind of agree with you.

The counter argument, however, is the primary radars, SSRs, and controllers are expensive to maintain. The faa is viewing this as an increased capability for less money, pretty good business case.

ajay

Originally Posted by PaigeHoffart

Thread drift...

I'd think homeland defense would be reason enough to keep primary radars. I also like it when approach points out targets without transponders. Cubs, crop dusters, and large flocks of birds show up on primary radar.

10M accuracy? Who needs that type of accuracy for traffic avoidance? Now if you're an airliner doing an ILS on 17C with someone else doing simultaneous approaches on 17L and 17R at a large hub, maybe. That doesn't mean that we need to equip the whole fleet. ADS-B would also be great for remote or oceanic areas but we already have a system for that called TCAS.

Another thing to consider is failure modes (besides the GPS constellation). What happens when your ADS-B box fails? At least we have a few layers of redundancy now (Primary radar, SSR, overlapping coverage)

Paige