Re: [Drip] how you can help (was: ADSB)

[Robert Moskowitz <[e-mail]>]

Here here.

As my Brit colleagues might say.

I don't see you registered for IETF117, so we will can just discuss over 
emails.

Look at the initial work items.  But also the other drafts I have penned 
to move our DRIP work along with things happening in UAS/UTM where we 
can perhaps contribute.

Also I need help with SCHC on some of the drafts.  Can you help me there?

Bob

On 7/12/23 12:04, Stu Card wrote:
> Alexey --
>
> I greatly appreciate your efforts to contribute to DRIP work.
>
> I only ask that you try to stay on topic, within the scope of what our 
> WG is chartered to and could feasibly do.
>
> Many things are broken in this world, we cannot fix them all. Just 
> within aviation related instrumentation and communication, there are 
> many problems, some of them long-standing, that the DRIP WG cannot 
> even address. You have mentioned some of them, like what is really 
> meant by AGL, for which there are competing definitions, which one 
> hardworking smart knowledgeable friend of ours has dedicated much 
> effort to trying to reconcile. But those are mostly _aviation_ issues, 
> not UAS RID specific, much less in DRIP scope.
>
> We need to refer, in DRIP,  to much external context. We must not be 
> distracted by constantly caveating those references with our own 
> opinions about them, changing their terminology to something we like 
> better, translating their units (when readers can easily do their own 
> unit conversions if needed), etc.
>
> We must focus our efforts on what we uniquely can contribute to making 
> UAS RID more useful: _trustworthy_ & _immediately actionable_ to 
> benefit safety & security of participating & nonparticipating people, 
> property, and the environment.
>
> To contribute to this important work, keeping the above in mind, 
> please review our *DRIP Entity Tag Authentication Formats & Protocols 
> for Broadcast Remote ID *draft at
> https://datatracker.ietf.org/doc/draft-ietf-drip-auth/
>
> Then please review the *DRIP Entity Tag (DET) Identity Management 
> Architecture *draft. If you really want to dig in, volunteer to 
> co-author some of the registry related drafts.
>
> Thanks!
>
> -- Stu
>
> Get Outlook for Android <https://aka.ms/AAb9ysg>
> ------------------------------------------------------------------------
> *From:* Alexandre Petrescu <[e-mail]>
> *Sent:* Wednesday, July 12, 2023 11:13:50 AM
> *To:* Stu Card <[e-mail]>
> *Cc:* [e-mail] <[e-mail]>
> *Subject:* Re: [Drip] ADSB
> thanks for the clarification
> I must have endeavoured in unchartered lands...
>
> Just to clarify: I am not disputing.
>
> I came with this thread to say that I saw ADS-B drones on flightradar.
>
> That's about it.
>
> Alex
>
> Le 12/07/2023 à 16:56, Stu Card a écrit :
> > The UAS RID rules are _not_ defined in this WG!
> >
> > They are defined by Civil Aviation Authorities (CAAs) in each
> > jurisdiction, with coordination via the International Civil Aviation
> > Organization (ICAO).
> >
> > Disputing the rules should be taken up with them, not with the DRIP WG
> > or any part of IETF.
> >
> > Such rules are mentioned in DRIP docs only as background: motivation,
> > context & constraints.
> >
> > Standard Means of Compliance with UAS RID rules, in turn, is mostly the
> > province of SDOs other than IETF, primarily ASTM International. Again,
> > disputing those standards should be taken up with those SDOs, not us.
> >
> > Only if some reference, in DRIP docs, to the rules or external
> > standards, is factually incorrect or unclear in expression for
> > understanding by DRIP protocol implementors, is it something we should
> > be debating here.
> >
> >
> > Get Outlook for Android <https://aka.ms/AAb9ysg>
> >
> > ------------------------------------------------------------------------
> > *From:* Alexandre Petrescu <[e-mail]>
> > *Sent:* Wednesday, July 12, 2023, 10:43
> > *To:* Stu Card <[e-mail]>; Robert Moskowitz
> > <[e-mail]>; Carsten Bormann <[e-mail]>
> > *Cc:* [e-mail] <[e-mail]>
> > *Subject:* Re: [Drip] ADSB
> >
> >
> >
> > Le 12/07/2023 à 16:00, Stu Card a écrit :
> >> Very short answers (all for which I have time):
> >>
> >> The rules for RID are based not primarily on RF considerations, but
> >> on aviation considerations.
> >
> > hmmm... it's a principle that is reasonable and that could be debated.
> >
> > One will excuse me for not knowing precisely what are the RID rules.
> > The RID rules are defined in this WG and I will need to look at them.
> >
> > If I look at them, one day, I will look at them from this perspective:
> >
> > For example, when RID rules say 'altitude' they should say 'altitude
> > expressed in meters and not in feet as is currently the inherited case
> > from WWII development of aviation'.
> >
> > This kind of text could be of enormous help to implementers: they simply
> > would need to call less functions(), because less need of conversions.
> >
> > It is the same when RID rules say 'heading' or 'speed', or when we talk
> > about airport track orientation.  It should be made easy to implementer
> > to compare a heading value in a 'heading' of a UAS to that of a track.
> > One should come up with a single common way of expressing track
> > orientation, compatible to that of RID rules, instead of several and
> > incompatible, as is the case in current air flight industry.  It is
> > because if one does that (interoperable defs of headings) then the
> > programmer has an easier task.
> >
> > Also, about RID rules: they should say that when ASTM wants to send
> > position and heading they should send the NMEA statements, without
> > conversion.
> >
> > Until then, if we can not do that, we can also have a human listening to
> > the radio airport and maneouvering locally or from a distance, using an
> > innombrable number of calculators and conversions, after having learned
> > tomes of manuals about how to fly things.  It is basically easier.
> >
> >>
> >> Crewed aircraft _mostly_ fly above 500 feet, except during takeoff
> >> and landing.
> >
> > I always had problems with this term 'crewed' aircraft.  I noticed it
> > also in the TVR WG, in its reverse form 'uncrewed' aircraft.
> >
> > But in reality there can be uncrewed crewed aircrafts too (Unmanned Air
> > Mobility device, a flying taxi, does carry a couple of persons on board
> > - 'crew?', yet none of them actually drives the UAM - they just signed
> > the insurance agreement).  An uncrewed aircraft is still crewed by the
> > fact that a (group of) persons on the ground is its crew (drone Reaper
> > is such).  There can also be these devices that are not crewed, are not
> > continuously driven from a ground by a crew, yet there are very many
> > eyes of people loooking at where it is going to - they're
> > pre-programmed.  These would be the true 'uncrew' aircraft even though
> > there are many crews simply looking at them.  They fly at more altitudes
> > than 500 feet.
> >
> > This is why I am not sure how to use this term 'crewed aircraft'.
> >
> > But I think you meant a 200 passenger aircraft like a regular airline
> > flight from a city to another.  Even that can be automated 
> (crewless?) soon.
> >
> >> Small uncrewed aircraft _mostly_ fly at much lower
> >> altitudes, as they are flown largely not to get from one place to
> >> another, but for photographing or otherwise sensing things on the
> >> ground (or for recreation).
> >
> > BEcause of this term 'crew' I can not say whether I agree or not 
> with you.
> >
> > Instinctively, I'd say that there are so many other flying aircraft that
> > it is hard to say so easily at which altitudes are they allowed or not,
> > simply based on that 'crewed' qualifier.
> >
> > I think the point of view of 'crewed' vs 'uncrewed' is limited in
> > itself, leading to potentially missing some aspects.
> >
> >> The FAA has established an upper limit
> >> of 400 feet AGL for small uncrewed aircraft flying under their rule
> >> appropriate for most such, to provide 100 feet of vertical
> >> separation from these small UAS and where the crewed aircraft
> >> _mostly_ fly.
> >
> > I will not oppose - maybe it is sufficient for them.
> >
> > If I were to be picky, I'd say that the notion of 'AGL' itself can be
> > subject to debate (there are several sea levels in this world and
> > moreover they change as we speak) and if one asks why then I reply that
> > if one would like to put NMEA statements in ASTM messages for the goal
> > of avoiding conversions then one might be facing such aspects of
> > precisely what is a sea level.
> >
> > But I will not go to the respective SDO, so I leave it there.  I agree
> > they set limits where they need them.
> >
> >> WRT units: yes it is a mess; no the EU does not use precisely the
> >> metric equivalents of feet etc. in their rules; note my original
> >> message said "EU rules are similar" not "EU rules are the same
> >> except for translation of metric units".
> >
> > I agree, you did not say that.
> >
> >> IETF does not get to write rules for aviation, therefore neither
> >> does IETF get to write rules for aviation communications; we can
> >> only provide technical standards for interoperable network protocols
> >> that _enhance_ those communications.
> >
> > It's a good thing, because enhancing communications is always good.
> >
> > Alex
> >
> >>
> >> -----Original Message----- From: Alexandre Petrescu
> >> <[e-mail]> Sent: Wednesday, July 12, 2023 9:45 AM
> >> To: Robert Moskowitz <[e-mail]>; Carsten Bormann
> >> <[e-mail]> Cc: Stu Card <[e-mail]>;
> >> [e-mail] Subject: Re: [Drip] ADSB
> >>
> >>
> >>
> >> Le 12/07/2023 à 13:56, Robert Moskowitz a écrit :
> >>>
> >>>
> >>> On 7/12/23 06:45, Carsten Bormann wrote:
> >>>> On 2023-07-12, at 11:52, Alexandre Petrescu
> >>>> <[e-mail]> wrote:
> >>>>> why not 400m
> >>>> This is not a domain where we get to invent boundaries.
> >>>>
> >>>> (Also, generally speaking, of course we should have a strong
> >>>> bias to using SI units, but in a domain where regulation is
> >>>> widely based on furlongs per fortnight, we’ll have to adapt.)
> >>>
> >>> And anyway it would be 125M to be a bit more than the Imperial
> >>> 400'.
> >>
> >> True.
> >>
> >> And it obviously begs the question whether in Europe they also have
> >> the same limit of 400' equivalent in meters.  I strongly doubt that
> >> an EU document would talk about a limit of precisely 121.92 meters
> >> just because of being converted to the easy to grasp 400 feet.
> >>
> >> At that point we talk about devices that might be different in an EU
> >> market than in an US market.
> >>
> >> What is the EU altitude limit for numerous drone aircraft to be
> >> considered flying very low, so numerous and so low such as to be
> >> forbidden to carry ADS-B equipment (or turn it off at lower than
> >> that altitude if it carries one)?
> >>
> >>> Why 400'?
> >>>
> >>> I think it was to keep general aviation some reasonable distance
> >>> above people on the ground.  As the ceiling for UA that is a
> >>> consequence.
> >>
> >> You see, I think there is an error.
> >>
> >> 400 feet might be a good limit in terms of separation of people and
> >> objects above their heads, but it is certainly not any limit in
> >> terms of radio communication.
> >>
> >> If there is to be a radio communication limit (use or not use ADS-B)
> >> it should be based on the power levels it uses and the guarantees of
> >> range. In WiFi, bluetooth and 2G..5G that's how they separate.
> >>
> >> For example, an 5G-carrying UAS would be limited to 450meter
> >> altitude because that is how high the ground 5G oriented towards
> >> ground reaches high.
> >>
> >> A bluetooth-carrying UAS (and not carrying ADS-B) would be limited to
> >> 100 meter altitude because that is how high a bluetooth device is
> >> allowed to emit, by bluetooth regulation.
> >>
> >>> "They can't go any lower, you can't go any higher."
> >>
> >> Strange.  Many devices, especially those who plane or glide like
> >> these UAS drones, and helicopters too, will stay stable at very many
> >> low altitudes.  Their power systems - more and more performing,
> >> allows for that.
> >>
> >> I very well see a helicopter stable 100meter above the ground, and
> >> surely it carries an ADS-B device, if not several of them.
> >>
> >>>
> >>> It is called boundaries to keep unequal players apart.
> >>>
> >>> One of the interesting debates in this is that the 400' floor is to
> >>> ground obstacles like radio towers.  Thus since big birds have to
> >>> stay 400' from that 700' radio tower down the block, you can take
> >>> your UA up to 1100' right next to it...  Or so some claim.
> >>
> >> Right!
> >>
> >> RAdio towers, or radio towers with even higher anti-flash
> >> ('paratonnerre', fr.) on them?  That adds some 10 meter to the
> >> picture, to which an UAS drone would need to pay attention, just
> >> like helicopters need to care about power lines above ground too.
> >>
> >>>
> >>> And speaking of Imperial vs Metric...
> >>>
> >>> Civil aviation separation is 1000'.
> >>>
> >>> This has already caused incidents where a lesser  Metric distance
> >>> was used by one aircraft against one using the greater separation
> >>> of Imperial.
> >>>
> >>> Fun!
> >>>
> >>> Not.
> >>
> >> I agree.
> >>
> >> Alex
> >>
> >>>
> >>> Bob
> >>>
> >
>