Date: 29 Nov 97 03:24:31 From: email@example.com (Edward Hahn) Organization: The MITRE Corporation References: 1 2 3 4 5
View raw article or MIME structure
>Jan-Olov Newborg wrote: >> >>SNIP >> 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. >> >> http://www.lfv.se/ans/card/news.htm >> >> 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 interested. 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 | firstname.lastname@example.org | (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.