Investigation of radiation doses at aircraft altitudes during a complete solar cycle

Studies of the radiation field at aircraft altitudes produced by galactic cosmic radiation and particles of solar origin have been carried out since the early nineties with the support of the European Commission. Extensive measurements made during solar minimum are now being extended through the solar maximum period of the present solar cycle. Active and passive detectors, some of which were developed for this work, are being exposed on several air routes covering a wide range of altitudes and latitudes. By the exposure of active detectors for the longest possible periods it is hoped that a number of measurements will be made during solar energetic particle events so that any effects at aircraft altitudes can be investigated.