SPELL=gr-air-modes
         VERSION=$(get_scm_version)
          SOURCE=${SPELL}-git.tar.bz2
SOURCE_DIRECTORY=$BUILD_DIRECTORY/${SPELL}-git
      SOURCE_URL=git_http://github.com/bistromath/gr-air-modes.git:${SPELL}-git
   SOURCE_IGNORE=volatile
  FORCE_DOWNLOAD=1
SOURCE_DIRECTORY="${BUILD_DIRECTORY}/${SPELL}-git"
        WEB_SITE="https://github.com/bistromath/gr-air-modes/"
      LICENSE[0]=BSD
         ENTERED=20150819
           SHORT="a software-defined radio receiver for Mode S transponder signals"
cat << EOF
gr-air-modes implements a software-defined radio receiver for Mode S
transponder signals, including ADS-B reports from equipped aircraft.

Mode S is the transponder protocol used in modern commercial aircraft.
A Mode S-equipped aircraft replies to radar interrogation by either ground
radar (secondary surveillance) or other aircraft ("Traffic Collision Avoidance
System", or TCAS). The protocol is an extended version of the Mode A/C protocol
used in transponders since the 1940s.  Mode S reports include a unique airframe
identifier (referred to as the "ICAO number") and altitude (to facilitate
separation control).  This receiver listens to the 1090MHz downlink channel;
interrogation requests at 1030MHz are not received or decoded by this program.
EOF