ATC use of Aircraft-Derived Data (was Re: 747-400 Initial Cruise)

Date:         29 Nov 97 03:24:31 
From: (Edward Hahn)
Organization: The MITRE Corporation
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>Jan-Olov Newborg wrote:
>> If modern nav-ATC equippment for freer flight (lateral airways) like the
>> Swedish proposed ADS-B system, the problem not letting aircraft up high
>> enough initially would be solved.
>> US Airforce use the GNSS-transponder today for C5b Galaxy formation
>> flying and Navy F18 Hornet is testing it.

Please keep in mind that the Swedavia GNSS-transponder is only one of the
potential *technical* solutions to providing an air-to-air and/or air-ground
communications link.

The actual *application* area (i.e. using aircraft-derived position and other
information to reduce air traffic restrictions) might be implemented on any of
several potential technologies, provided the technology meets the
application's requirements for performance (e.g. range, reporting interval,
etc.)  Technologies which could fill this role are several different VHF
waveforms (including the Swedavia system as one candidate), a wide-band (~2
MHz) channel, and other alternatives.

The company I work for (MITRE CAASD) is doing research for the FAA in this
area, to determine a sound choice for a technical implementation.  Our work is
structured around the following methodology:

1) User Benefit (in this case, more consistent achievement of optimum initial
   cruise by air carriers)
2) Application Functional Requirements, based on what is needed to achieve the
   user benefit (e.g. enhanced ATC decision support tools)
3) Technical Performance Requirements, based on what performance the
   applications need (e.g. range, reporting interval, etc.)
4) Technical Implementation, based on what achieves the performance
   requirements, in addition to considering cost (both avionics and ground
   system), interoperability with international community, acceptance by the
   user community, availability of radio spectrum, etc.

Based on this methodology, we aim to provide the US FAA and the international
community with a recommendation on a sound technical solution for an
air-air/air-ground data link, one which will meet the performance requirements
for future applications, without requiring the users or the ground systems to
buy or replace several sets of avionics/ground equipment.

(Please note that there are actually two different concepts for transmitting
this data:  first is an "addressed" method, such as what the current "FANS1"
capability by Boeing provides, where a message is sent between a specific
aircraft and a specific ground facility.  The second is a "broadcast" method,
in which each aircraft makes a broadcast transmission of the information, and
everyone able to hear the message (both in the air and on the ground) can
decode it.

(Both methods have complementary advantages - the "addressed" method is useful
for oceanic and other areas where the ATC service provider may be separated by
several hundred or thousand miles, where line-of-sight ground equipment
installations, such as radars or VHF radios, are not feasible.   The
"broadcast" method is useful for air-to-air applications, where it would be
redundant to fill up RF spectrum to transmit the same information to multiple
interested parties.)

We have several papers and other materials available for those who are

Edward Hahn
Project Team Manager
Airborne Information Support Services
Communications, Navigation, and Surveillance Directorate
Center for Advanced Aviation System Development
The MITRE Coroporation

>>>>  Ed Hahn    |    |    (703) 883-5988  <<<<
The above statement is the opinion of the author.  No endorsement
or warranty by the MITRE Corporation is expressed or implied.
Really, I wouldn't kid you about a thing like this.