ADS-B, Stuff that I have found.

[Capn Bloggs]

Joker 10,

Fortunately, transponders will be part of the ATC system for many years (12-15 years for airplanes, probably longer for gliders), providing most of the safety benefits that ADS-B can provide.

What ATC system? That'd be using the extensive Australian radar coverage, would it?

[OZBUSDRIVER]

joke/2 gotta love those prices for UAT

When you snoop around the glider blog sites, they are pretty happy with the Trig gear especially.

[Flying Binghi]

#207 Jabawocky ...dont tell Binghy that...he will be in decine...

..."in decine"...




.

[The Chaser]

The "spoofing" theory is not so unbelievable though. That could easily cause a lot of mischief.

No it could not. The GNSS positional accuracy is (where required) confirmed both by the airborne sending unit, and independently via the ground station (where in coverage) receive timing. Also, don't forget that even if an ADS-B GNSS derived position is not (temporarily) broadcast as part of the 1090 message, the A,C and S data still is, and will be plotted where Multilat (non-dependent) and/or Mode S radar coverage exists (Capital city and surrounds).

Back to the sub-subject of GPS availablity/reliability

http://frwebgate.access.gpo.gov/cgi-...19346&TYPE=PDF

[/b]§ 2281. Global Positioning System[/b]

(b) SUSTAINMENT AND OPERATION FOR CIVILIAN PURPOSES.— The Secretary of Defense shall provide for the sustainment and operation of the GPS Standard Positioning Service for peaceful civil, commercial, and scientific uses on a continuous worldwide basis free of direct user fees.

In doing so, the Secretary—

(1) shall provide for the sustainment and operation of the GPS Standard Positioning Service in order to meet the performance requirements of the Federal Radionavigation Plan prepared jointly by the Secretary of Defense and the Secretary of Transportation pursuant to subsection (c)
(2) shall coordinate with the Secretary of Transportation regarding the development and implementation by the Government of augmentations to the basic GPS that achieve or enhance uses of the system in support of transportation;
(3) shall coordinate with the Secretary of Commerce, the United States Trade Representative, and other appropriate officials to facilitate the development of new and expanded civil and commercial uses for the GPS;
(4) shall develop measures for preventing hostile use of the GPS in a particular area without hindering peaceful civil use of the system elsewhere; and
(5) may not agree to any restriction on the Global Positioning System proposed by the head of a department or agency of the United States outside the Department of Defense in the exercise of that official’s regulatory authority that would adversely affect the military potential of the Global Positioning System.

(c) FEDERAL RADIONAVIGATION PLAN.— The Secretary of Defense and the Secretary of Transportation shall jointly prepare the Federal Radionavigation Plan. The plan shall be revised and updated not less often than every two years. The plan shall be prepared in accordance with the requirements applicable to such plan as first prepared pursuant to section 507 of the International Maritime Satellite Telecommunications Act 1 (47 U.S.C. 756). The plan, and any amendment to the plan, shall be published in the Federal Register.

ACCESS TO GLOBAL POSITIONING SYSTEM
Pub. L. 104–106, div. A, title II, § 279, Feb. 10, 1996, 110
Stat. 243, provided that:
‘‘(a) CONDITIONAL PROHIBITION ON USE OF SELECTIVE AVAILABILITY FEATURE.—Except as provided in subsection (b), after May 1, 1996, the Secretary of Defense may not (through use of the feature known as ‘selective availability’) deny access of non-Department of Defense users to the full capabilities of the Global Positioning System.
‘‘(b) PLAN.—Subsection (a) shall cease to apply upon submission by the Secretary of Defense to the Committee on Armed Services of the Senate and the Committee on National Security of the House of Representatives of a plan for enhancement of the Global Positioning System that provides for—
‘‘(1) development and acquisition of effective capabilities to deny hostile military forces the ability to use the Global Positioning System without hindering the ability of United States military forces and civil users to have access to and use of the system, together with a specific date by which those capabilities could be operational; and
‘‘(2) development and acquisition of receivers for the Global Positioning System and other techniques for weapons and weapon systems that provide substantially improved resistance to jamming and other forms of electronic interference or disruption, together with a specific date by which those receivers and other techniques could be operational with United States military forces.’’

Have a read of the full legislation. It makes quite clear why the US is not interested in any civilian 'unreliability' issues. Quite apart from the non-US Galileo and other interoperable constellations coming on line.

[LeadSled]

Perhaps INS, even "VOR calibrated" INS just aint that accurate eh. Jaba methinks yer putting up a red herring there..

Binghi,

Jaba is right, see FAA AC90-45A, the standard for area navigation. Available updating was DME/DME, DME/VOR or LOC, and the later addition of GPS as an update source didn't change the Doc. 8168 rules for an "area nav" approach.

Even when we got the GPS update in suitable INS equipped aircraft, the minima were still the same as a VOR/DME approach (generally 400'/1 nm, except in Australia).

All the original "area nav" approaches in US were overlay approaches, you just followed the profile of a VOR or NDB approach.

Indeed, there were many area nav devices available in the US from the late 1960s, we never saw then in Australia, because we never had the density of VOR or proper DME, and still don't.

All QF 747, and subsequent types in the fleet (all B767 and later B737, and, I would assume, various Airbus to the JAA/EASA equivalent) ) are certified re. AC90-45A.

Tootle pip!!

Chaser,
Maybe you are not aware, but US forces (and, I would assume, other countries) can very effectively spoof/deny GPS coverage in (sort of) specific areas, as a nornal precaution. It works well, I know, because we got caught on the edge of an exercise --- it really screwed up the GPS feed to the IRS/FMCS system.

[T28D]

In fact it is just time shift technology, simple really if you can handle the physics involved.

One could chase ones tail all over the place seeking to validate a rational response to the technology available to the designers and owners of the GPS system but it is factual that they ( THE U.S. Government ) "own" the system and despite all the heart felt angst, they will do with it ( the system) as they ( the government) see fit and the rest of us can cry unfair till our lungs dry up, face it the system is theirs !!!!!!!!!

[The Chaser]

You are very good at arguing the same points made by others after the fact ol' fruit

Yes I am very well aware, that is why I posted the US government legislation on the previous page . It is clear the economic, social, and safety impacts of selective, tactical removal of signal are considered, and by design protected (where the signal is safety critical) by all of those system devices (such as RAIM, cross reference NAV, back-up NavAid, etc etc) for just such cases.

Do any of you really think there are not protocols in place between sovereign governments (including ours) and the US specifically dealing with these issues!? ... no doubt the same with the Euro's on Galileo

As far as this diversionary subject is concerned, it is well known by those who have half a clue that the aviation systems are designed to be fail SAFE. In other words, even if the constellation/s were not available at zero notice, there are other NAV, ATS etc system contingencies in place to ensure air traffic can immediately recover in to a less efficient, but safe operating mode.

T28 ... Atomic Time shift is but one method

[T28D]

The clock is atomic, the shift is applied physics.

[baswell]

Selective Availability

It is clear the economic, social, and safety impacts of selective, tactical removal of signal are considered

"Selective Availability" is just that - "selective". What happens if the US has a bit of biffo with some of our northerly neighbours? They can decide to deny them (and thus us!) availability of GPS, while everything is hunky-dory in the Americas and Europe. Considered and actioned.

I know officially new satellites are launched without the capability - but that doesn't mean some new software can not be uploaded at any time.

There is one major issue with turning on SA in this day and age, though: they can only do it once. It will take experts only a few days to crack it and the enemy front-line troops will have Android phones with perfectly operating GPS in weeks. The next line of consumer and aviation GPSs will have upgradable firmware to get updates for the hacks.

In any case, that's why we should support Galileo and have dual receivers. Push come to shove, some government controls that too, but the more systems we have, the less likely it is they all go down.

[OZBUSDRIVER]

Thanks to Zeke for the link-

GNSS outage due to DOD testing

Take a look at the map...Comments Mr bomber? 215nm radius @ 4000ft. Truelly global in area!

Pilots are highly recommended to report anomalies during testing to the appropriate ARTCC to assist in the determination of the extent of GPS degradation during tests.

Interesting!

If the DOD is interested in feedback....suggests the DOD doesn't have to turn off the entire network to have the desired effect in a war theatre sized area of the planet.

[OZBUSDRIVER]

Backhand thanks to Plumbum and thanks to the chaser for the link-

FAA FACES SIGNIFICANT RISKS IN IMPLEMENTING THE AUTOMATIC DEPENDENT SURVEILLANCE – BROADCAST PROGRAM AND REALIZING BENEFITS

Worth the read...as the Plumbum says, keep an open mind and thank the deity that we didn't follow the yanks on this one.

[Flying Binghi]

ADS-B related stuff that i have found...

ADS-B related stuff that i have found.... apparently, we have established that the Oz gov/ASA don't have any agreement with the owners of them magic GPS signal generators that ensures them magic signals keep on coming. And ah see's the Japanese are getting their own GPS sat's up because, in part, they have a concern that them yank GPS sat's will stop with the civvy signal... and yer gotta ask, if the yanks are turning off the civvy signal, wont every other GPS sat owner be doing the same...

So, ADS-B needs GPS for it to work and we have no guarantee of supply of this critical input - a very bad business case just for starters..

In the meantime, before we cargo cultists loose them GPS signals, what will probably happen as pointed out by other posters is we end up with full flight charging - every flight, all flights. The Chaser and OZBUSDRIVER have helpfully pointed out just how safe it is for every pilot to see really flight critical 'traffic' out to 500 miles, or 4 hours, so how can we object..

The other thing that will blossom under the ADS-B system, while we got it, is them civvy UAV operators. UAV's (Unmanned Aerial Vehicles) will more then likely need ADS-B to be able to operate. With the help of ADS-B ah guess civvy UAVs will displace many of the helicopter and fixed wing operators that are currently doing observation work - probably will be hundreds of the things flying around big city's... IMO, a great lark if yer can get it - current aircraft owners pay for the establishment of ADS-B and the UAV operator's just walk in and take the business for free..


...anyway, nuff for now..




.

[OZBUSDRIVER]

Show me where it is printed the US Government will turn off the entire network Binghi....and I will believe you....All I have seen is assesment of risk...vanishingly small, maybe?

The Japs have MTSAT to enhance their GNSS signal from the network...not replace it...it is an interoperable WAAS satellite...They want Australia to play as well. that would mean Australian government expenditure and with such a broad user base...it is impossible to make one user group pay for the entire network...otherwise we would have the same precision approaches as the yanks to any aerodrome you want to write a procedure for...even somewhere like Benalla or Lockhart River.

The Russians with GLONASS, The europeans with Galilao, The Chinese with Beidou are yet to launch any workable network. The Indians and the Japanese have launched geosynchronous WAAS satellites...enhancing the GNSS, not replace it.

You cannot fear what your own government does to you, Binghi...if you do not like what they do...lobby and, ultimately, vote for a change...we are a democracy, after all.

As for civvie UAV...because they do not have an eyeball in a cockpit they do need an active means of seeing aircraft around them...Sorry, but I still haven't seen a TCAS that small to fit in such a small airframe...ADS-B enables the technology...you see the hinderance I see the possibilities of UAV to go where it is too risky to send a human or too long or too mundane...and...they still have to pay for the enabling equipment the same as an aeroplane owner so they do not get something for free.

Half full or half empty...your choice Binghi.

[OZBUSDRIVER]

AS much as I love linking to Wiki-

Other Uses

There are plenty of applications that can be used as a tolling method...and a very accurate one at that! A few years ago the NSW government wanted to make every heavy vehicle owner pay for a GPS receiver/logger so the government could charge a toll for the use of the Pacific Hwy..also as a check to ensure the vehicle only used designated roads. the NSW police still have the intent of desiring a logger that will be admissible evidence in a court to be able to detect and prosecute speeding and driving hours enfringments without intercepting a single vehicle. All capable because of GPS.

Free kick for you, Binghi...read my first post on this thread...information...make up your own mind.

And....still number three or at least first page of a google search for ADS-B or 1090ES bet the boys in blighty are happy about that

[Tidbinbilla]

Keep it real, people!

The thread topic is ADSB. I have moderated 47 posts in order to bring it back on track.

Other similar threads became heated and personal, and have hence been either closed or deleted.

The moderators will be watching this thread (and the antagonists) closely. Any repeats of poor behaviour will not be tolerated, and will result in individuals being dealt with firmly and decisively.

TID.

[OZBUSDRIVER]

AVwebFlash Complete Issue...

sorry guys....doing this from my phone...general gist.....new 4G Phone network will be operating on the adjacent frequecy range...may be enough to cause serious interferance within 5nm of a transmitter.....40,000 of them

EDIT- thanks mods for fixing link...understandably, this is in the US...however, it may well end up here.

[CaptainMidnight]

The GPS jamming is happening here. 18 hours per day continuously (supposedly) for a month. The area covers a few aerodromes in the area to the east (AMK etc) and affects routes over and in the vicinity of WR. And there is an ADS-B site there.

C0717/11
GPS RECEPTION MAY BE UNRELIABLE WI 80KM OF S31 00 E136 36 (APRX 15NM NW WOOMERA)
CONTROLLING AUTHORITY: DEPARTMENT OF DEFENCE
PRIMARY CTC 0408 402 241 SECONDARY CTC 08 8674 3370
SFC TO UNL
FROM 02 091930 TO 03 111330 EST
DAILY 1930/1330

[The Chaser]

This is US stuff, but just in case the frail and infirm think it might migrate to OZ:-

http://www.gpsworld.com/gnss-system/...rder-fcc-10991

The National Telecommunications and Information Administration (NTIA) also has filed a letter expressing concern about the potential for adverse impact on GPS and other Global Navigation Satellite System (GNSS) receivers, as well as maritime and aeronautical emergency communication systems, and Inmarsat receivers used by Federal agencies.

We emphasize that the waiver is predicated on the specific combination of facts and circumstances before us. As such, and consistent with the comments of Iridium and AT&T, we limit the scope of this conditional waiver to LightSquared in its use of MSS L-band spectrum.

V. GPS AND OTHER INTERFERENCE CONCERNS

A. GPS-Related Interference Concerns

39. Several commenters raise concerns about potential interference to GPS receivers and other devices that may result from operation of LightSquared’s base stations, while LightSquared asserts that it continues to meet its obligations with regard to addressing interference concerns. NTIA also expresses concern that LightSquared’s services could adversely impact GPS and other GNSS receivers, and asks that the Commission address these inference issues before interference occurs. We emphasize that any potential interference to GPS is a significant concern, and note that the Spectrum Task Force at the Commission recently established an internal technical working group dedicated to examining this issue.

40. The U.S. GPS Industry Council proposes that NTIA, working with industry and government technical experts, examine the potential for interference within a reasonable time frame, not to exceed 90 days. In its letter, NTIA states that, if the Commission grants LightSquared’s request, the Commission should establish a process that will ensure the interference issues are resolved prior to LightSquared’s offering service that could cause interference, and that will motivate all parties to move expeditiously and in good faith to resolve the issues.139 NTIA further states that it stands ready to work with the Commission, LightSquared, and affected parties and concerned Federal agencies to address these interference concerns. More recently, LightSquared states that it takes the concerns raised by the GPS community about possible overload of GPS devices by LightSquared’s base stations very seriously, and that it is appropriate for interested parties to devote resources to a solution as soon as possible LightSquared professes confidence that the issues can be resolved without delaying deployment of its network. At the same time, in order to address the concerns raised, LightSquared states that it would accept, as a condition of the grant of its request, the creation of a process to address interference concerns regarding GPS and, further, that this process must be completed to the Commission’s satisfaction before LightSquared commences offering commercial service, pursuant to the approval of its request, on its LBand MSS frequencies. Further, LightSquared commits to working diligently and cooperatively with the Commission, NTIA and the Federal agencies, and the GPS community to help resolve the interference issues through a rigorous process that can address these issues in a comprehensive manner.

42. As an additional condition of granting this waiver, we require LightSquared to help organize and fully participate in the working group described above. The working group shall focus on analyzing a variety of types of GPS devices for their susceptibility to overload interference from LightSquared’s terrestrial network of base stations, identifying near-term technical and operational measures that can be implemented to reduce the risk of overload interference to GPS devices, and providing recommendations on steps that can be taken going forward to permit broadband wireless services to be provided in the LBand MSS frequencies and coexist with GPS devices.

43. Further, we require that LightSquared submit an initial report to the FCC and NTIA by February 25, 2011, that includes a work plan outlining key milestones for the overall analyses. In addition, LightSquared must submit progress reports on the 15th day of each succeeding month or first business day thereafter. The first of these reports must at a minimum include base station transmitter characteristics, categories of GPS devices and their representative performance characteristics, and test plans and procedures. LightSquared is further required to submit a final report no later than June 15, 2011, that includes the working group’s analyses of the potential for overload interference to GPS devices from LightSquared’s terrestrial network of base stations, technical and operational steps to avoid such interference, and specific recommendations going forward to mitigate potential interference to GPS devices. The Bureau reserves the right to adjust the reporting dates and requirements in consultation with NTIA. The process will be complete once the Commission, after consultation with NTIA, concludes that the harmful interference concerns have been resolved and sends a letter to LightSquared stating that the process is complete.

We’ll all be roooned ….. NOT!!!!

[OZBUSDRIVER]

Googling info..IT side think GPS issue is minor...Aviation/DoD/ side think there are major issues with freq band being so close...not just those 40000 land sites but two satellites covering all of the US by 2015.

Funnily enough, both sides think the FCC is their friend.

EDIT to add. lightsquared are/have been accumulating bandwidth for the last eight years...this last bit is AFTER they have flown their birds into space and now they want to get a licence from the FCC?

[T28D]

Aquote from the EAA Magazine

The important thing to know is that LPV guidance in your instrument panel behaves just like an ILS signal. Other RNAV or GPS approaches present linear guidance, meaning one dot of deviation equals the same distance off the centerline no matter how far you are from the runway or waypoint. The LPV, like an ILS, shows angular deviation, so any tracking error shown on your instruments narrows as you near the runway. Like an ILS, when you get to the runway threshold, a dot of deviation off centerline equals only a few feet of actual distance from the center.
If it were up to me, I’d use linear deviation guidance for all approaches because I think that method is easier to fly. The “sensitivity” of the linear display stays the same all the way to the runway, while the LPV, like the ILS with angular deviation, “cones in” the closer you get to the decision point. But the FAA people who created the LPV specs wanted LPV to behave exactly like an ILS, so we pilots don’t need to learn anything new. Old dogs, new tricks – that sort of thing.
In spite of having angular deviation, I have found the LPV easier to fly than an ILS because the GPS-derived LPV guidance is rock steady. You don’t realize how much a typical ILS signal is wandering around until you fly with LPV on one display and raw data ILS on the other. Because it is an analog signal, and its radio beams are susceptible to all sorts of reflection and distortion, the ILS guidance can never be as steady as the LPV, which comes from a new GPS position and velocity calculation being made several times each second.
All of this has taken on new significance to me given the several potential GPS interference sources that are in the news. If I lose GPS guidance en route, it is important because that is my primary source, but there is a lot of time and several navigation alternatives to fall back on. If nothing else, the controller’s radar can provide guidance en route to get you where you are going. But if GPS signals are interfered with while you are flying a few hundred feet above the ground on an instrument approach in the clouds, snow, or murk, that is a different and much more critical matter.
A potential wide-scale GPS interference source is a new 4G broadband Internet network called LightSquared that has been given preliminary approval by the FCC. LightSquared’s proposed thousands of transmitters would operate on frequencies closely adjacent to the GPS frequencies. The GPS industry is very concerned that the comparatively powerful transmitters of the network will cause widespread interference and loss of navigation for airplanes flying within miles of the transmitters. Garmin is among those expressing concern to the FCC about the new network. The FAA is also onboard in seeking to prevent possible GPS interference.
But there is also potential GPS navigation interference already out there from some unknown number of GPS jammers that are sold mostly over the Internet. These devices are designed to temporarily disable a GPS device that may be in your car or truck and is transmitting your movements to others. If you don’t want your spouse to know where you are, or don’t want the boss to know how fast you’re driving (or not driving), these jammers can block reception of GPS signals by a receiver in your vehicle.
Using a GPS device to record, then transmit, the location and movement of a vehicle has become very common. For example, trucking companies want to know where their trucks are located and how well they are progressing toward the destination, and a GPS device can automatically send that information. You can also imagine why people would be curious about the movement and location of others and could “plant” one of these small GPS devices in a car to report its activity. Let’s just say these devices create a privacy issue.
The jammers that can prevent GPS reception cost only a few hundred bucks. The jammers are in a legal gray area at best, but they are proliferating. The effective range of most jammers is advertised to be in the 10s of meters, with some I have seen claiming to disable a GPS and cell phone out to 40 meters. That’s no issue for airplanes at cruise altitude, but what about nearing the decision point of only 300 or so feet above the runway on an LPV approach? The jammer would have to disrupt the signal for only a couple seconds to create a problem at the end of a GPS approach.
All of us should be concerned about the possible interference of new networks such as LightSquared. But those transmitters are regulated. If public pressure is kept on the FCC, as I know it will be, testing and modification if necessary can protect GPS operation interference from legal and authorized broadcasts.
That is not true for the many small portable devices designed specifically to interrupt GPS reception. That is a cat and mouse game in which those who want the information GPS can provide will continually search for ways to defeat the jammers. Those who want privacy from GPS reporting on their activities will pay more and more for powerful devices that provide privacy. It’s a GPS issue not envisioned when the system was designed by the Air Force for military navigation and weapons guidance beginning about 40 years ago.
Newly designed GPS satellites will contain advanced technology to help prevent jamming, but those satellites will take years to deploy. And the people designing the jammers won’t stand still in their search to find more effective ways to block GPS reception.