GPS Jamming/Spoofing Threat

[Jerry 5TJ]

8 hours ago, 0TreeLemur said:

The KNS81 is thinner- Is that a good box too? 

The KNS81 requires an external KN63 remote mount DME and the KDI572 panel display.  The all-in-one-box KNS80 is much more common.  

[Schinderhannes]

15 hours ago, 0TreeLemur said:

Jerry- this is just the kind of input I was seeking.  What is the weight & power requirements for such a box?

Looking at the KNS80, its kind of tall for the amount of free space in my radio stack.   The KNS81 is thinner- Is that a good box too?  Looks newer.

-Fred

The KNS81 requires input from a DME and KNS81 and DME take about the same space as the KNS80.

[Jerry 5TJ]

On 1/23/2021 at 7:07 PM, EricJ said:

It's a lot more than a few lines of code, but it isn't anything earth-shattering, for sure, and well within the capabilities of most decent SDR platforms these days.

 

I forgot to turn on the green font.  

[Hank]

4 minutes ago, Jerry 5TJ said:

I forgot to turn on the green font.  

???? Wuzzat?

[1001001]

The KNS-80 is a big box, and there are issues with the displays--it is hard to find replacements if the display quits.  I can't remember the breaker size/power requirement on the one I had in my old Warrior, but I still have the unit, just in case.

[0TreeLemur]

3 hours ago, 1001001 said:

The KNS-80 is a big box, and there are issues with the displays--it is hard to find replacements if the display quits.  I can't remember the breaker size/power requirement on the one I had in my old Warrior, but I still have the unit, just in case.

The KNS-80's I see for sale have delaminated displays and seem pretty tired.  I've only got less than about 1-1/2" of free radio stack space.

[0TreeLemur]

14 hours ago, PeteMc said:

I have a KNS-80 that was recently pulled out.  Working fine when it was removed.

 

I see online that the KNS-80 is 3" tall, and my space limited C panel radio stack hasn't enough free room.   It could go into the right-hand side of the panel but that requires a major redo, and I like the iPad over there...

To answer two of my earlier questions- I found that it weighs 6 lbs and has an average power consumption of 25W.

 

[Schinderhannes]

On 1/23/2021 at 2:19 PM, N201MKTurbo said:

I bet you could get a DSP based radio chip for a Raspberry Pi, that you could receive VOR signals and DME signals and calculate a position almost as good as a GPS. It could have a database of all the stations and switch between them rapidly taking cross bearings and DME fixes. With a little extra work, it could do the ADF thing on broadcast AM and FM stations, that would be a great backup.

Maybe I have a retirement job. I could get @EricJ to help, he is a radio genius, he kind of designed WI-FI.

Something similar was available a long time ago. Just before the GPS age began Peschges Variometer had an add on for their final glide computer VP3e using a Becker NR3301 VOR calculating the position utilizing cross bearings and giving you the distance to your destination. The basic version used heading and airspeed aided by manual wind correction factor input. 

[Jerry 5TJ]

8 hours ago, 1001001 said:

The KNS-80 is a big box, and there are issues with the displays--it is hard to find replacements if the display quits...

Hey, the KNS80 design is 40+ years old.   Those old boxes are doing ok for their age.  

The OP wanted a non-GPS means of navigation.  The KNS80 is one.  
 

Of course we could design a better replacement today.  For a few thousand AMUs we could even get it certified for you.  

[irishpilot]

I’ll offer a counter point to buying outdated technology or retrofitting for an INS. The VOR Minimum Operational Network (MON) is designed for GPS outages. Spoofing is more difficult to detect in civilian equipment because there is no embedded INS or EGI to trip a warning when the two solutions diverge. This is why always flying with a VOR dialed in is important and is in good keeping with having a backup plan. 

The FAA VOR MON is designed so that any aircraft above 5,000’ AGL can safely navigate to an airport within 100NM of the MON designated VOR without the required use of DME or ADF. This way pilots can still rely on ILS/LOC/VOR ground based approaches in case of outages, or spoofing if noticed inflight. 

Oh yeah, the back-up to the back-up is still “Clock-Map-Ground”. Still taught to student pilots and a great skill to brush up on when bored on a XC flight. 

https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/transition_programs/vormon/

 

[0TreeLemur]

On 1/25/2021 at 4:28 PM, Jerry 5TJ said:

Hey, the KNS80 design is 40+ years old.   Those old boxes are doing ok for their age.  

The OP wanted a non-GPS means of navigation.  The KNS80 is one.  
 

Of course we could design a better replacement today.  For a few thousand AMUs we could even get it certified for you.  

What about the KNS-64?  That would fit in my panel.  Is that a stand-alone DME, or does it require other items like the -62?

[Jerry 5TJ]

1 hour ago, 0TreeLemur said:

What about the KNS-64?  That would fit in my panel.  Is that a stand-alone DME, or does it require other items like the -62?

The KN62 and KN64 are panel mount DME units with no RNAV capability.  They are capable of stand-alone operation or can be tuned by connecting to a compatible VOR radio.  

[0TreeLemur]

1 hour ago, Jerry 5TJ said:

The KN62 and KN64 are panel mount DME units with no RNAV capability.  They are capable of stand-alone operation or can be tuned by connecting to a compatible VOR radio.  

Like a KX-155?

[0TreeLemur]

An article written by Commercial Pilot Kate Murphy and published Jan 23, 2021 in the NYT that is relevant:

GPS_spoof_article.txt

[David Lloyd]

On 1/28/2021 at 8:30 PM, 0TreeLemur said:

Like a KX-155?

Yes. KX155/165 install manual, looks like a couple, three wires.  

[N201MKTurbo]

On 1/28/2021 at 6:30 PM, 0TreeLemur said:

Like a KX-155?

Channeling a Kn62/64 to a KX155 is very easy. There is a serial buss, it only takes 2 wires. You can channel it to other navcoms, but it takes a lot more wires. In my old Mooney the DME was not channeled to the navcom, tuning it manually was not a burden.

[0TreeLemur]

On 1/28/2021 at 3:31 PM, irishpilot said:

Oh yeah, the back-up to the back-up is still “Clock-Map-Ground”. Still taught to student pilots and a great skill to brush up on when bored on a XC flight. 

 

Not if you are in or above those pesky clouds.

[jlunseth]

I had a 430 put into my panel in about 2009, and I also had a KNS 80. The RNAV portion of it was never useful, by that I mean setting waypoints by radial and distance. There was no support for it anywhere. I tried a few times early on to map out a course with VOR/radial/distance waypoints and it just was not practical since ATC had no idea what you were doing. The only time I used the DME was to fly practice VOR approaches. The 80 also had an VOR/LOC receiver so I would put the ILS in as a backup, but I only recall that being useful once in ten years. I just had a GTN750Txi put in, and kept the 430. Both have Nav comms so I can receive an ILS or VOR, and they each have their own CDI. I had a used Collins DME installed just to have one. The 80 is gone, took up quite a bit of panel space. It was a very good unit in its day, but its day is over. Took out the ADF also.

[Jim Peace]

https://rntfnd.org/2021/02/01/sewage-plant-jams-gps-around-airport-avweb/

[0TreeLemur]

Precise INS systems remain expensive and subject to their own drift limitations.   A better scheme might involve beacons on cell phone towers transmitting gps-like signals.  Those signals would include the fixed coordinate of the transmitter rather than satellite ephemeris data, and time-coded messages.   Because they are much closer to the receiver, jamming them would require a lot more power.   These cell phone tower transmitters could get their reference time from the internet.  They probably already do in addition to GPS.  

Receivers would be cheaper, lighter and probably more reliable than INS and could be integrated with GPS.   This also provides GPS manufacturers supported by FAA mandate a chance to retire all current operating hardware and make some $$.  Remember ADS-B?   Seems so long ago. 

[tmo]

I'm sure this is already done as a means to do things like indoor navigation, GPS aiding and, most importantly, track phone movements with GPS turned off. Cell towers, wifi networks within range and their respective signal strength, etc.

I'm also sure the backend database to do this is huge in comparison to our air navigation data.

Thing is, when you fly high enough, you are unlikely to have any cell reception, much less wifi.

[0TreeLemur]

On 2/3/2021 at 2:43 AM, tmo said:

I'm sure this is already done as a means to do things like indoor navigation, GPS aiding and, most importantly, track phone movements with GPS turned off. Cell towers, wifi networks within range and their respective signal strength, etc.

I'm also sure the backend database to do this is huge in comparison to our air navigation data.

Thing is, when you fly high enough, you are unlikely to have any cell reception, much less wifi.

High enough you get good VOR reception though.   Ground based GPS transmitters make a lot of sense for non-precision approaches provided there are 3 towers in range.  A local transmitter at the airport could provide a fourth signal for reduced vertical error.  Plus a ground-based gps-like system would not suffer from ionospheric delay errors. 

I'm dreaming- just like I'm dreaming of a modern engine when my a/c is due for overhaul in a few years.

[tmo]

17 minutes ago, 0TreeLemur said:

Ground based GPS transmitters

Ground Based Augmentation System is definitely a thing, and used not only in aviation.

Thing is, if you want to provide redundancy for GPS spoofing, you cannot use GPS frequencies. VOR, yes. GSM/UMTS/5G, sure - but it has to be sufficiently different from the frequency range you're providing redundancy for. That's why Galileo or GLONASS or BeiDou and so on aren't a solution either - roughly same frequency bands are used in all of them.

It's nice to dream, isn't it?

[EricJ]

6 hours ago, tmo said:

Ground Based Augmentation System is definitely a thing, and used not only in aviation.

Aka Differential GPS.   It's been around for a long time.

https://en.wikipedia.org/wiki/Differential_GPS

 

 

[0TreeLemur]

7 hours ago, tmo said:

Ground Based Augmentation System is definitely a thing, and used not only in aviation.

Thing is, if you want to provide redundancy for GPS spoofing, you cannot use GPS frequencies. VOR, yes. GSM/UMTS/5G, sure - but it has to be sufficiently different from the frequency range you're providing redundancy for. That's why Galileo or GLONASS or BeiDou and so on aren't a solution either - roughly same frequency bands are used in all of them.

It's nice to dream, isn't it?

Great point.  We'll definitely be forced to buy new equipment.