ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-20-1693-2002 <i>Letter to the Editor</i> <br>Energy spectrum of secondary protons above the atmosphere measured by the instruments NINA and NINA-2 Bidoli V. 8 9 1 Casolino M. 1 De Pascale 1 Furano G. 1 Iannucci A. 1 Morselli A. 1 Picozza P. 1 Sparvoli R. 1 Bakaldin A. 2 Galper A. 2 Koldashov S. 2 Korotkov M. 2 Leonov A. 2 Mikhailov V. 2 Voronov S. 2 Boezio M. 3 Bonvicini V. 3 Vacchi A. 3 Zampa G. 3 Zampa N. 3 Ambriola M. 4 Cafagna F. 4 Circella M. 4 De Marzo C. 4 Adriani O. 5 Papini P. 5 Spillantini P. 5 Straulino S. 5 Vannuccini E. 5 Ricci M. 6 Castellini G. 7 University of Rome “Tor Vergata" and INFN section of Roma2, Rome, Italy Moscow Engineering Physics Institute, Moscow, Russia University of Trieste and INFN section of Trieste, Trieste, Italy University of Bari and INFN section of Bari, Bari, Italy University of Florence and INFN section of Florence, Florence, Italy INFN National Laboratories of Frascati, Frascati, Italy Institute of Applied Physics “Nello Carrara", CNR, Florence, Italy Correspondence to: R. Sparvoli (Roberta.Sparvoli@roma2.infn.it) 31 10 2002 20 10 1693 1697 Copyright: © 2002 V. Bidoli et al. 2002 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/20/1693/2002/angeo-20-1693-2002.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/20/1693/2002/angeo-20-1693-2002.pdf

In this paper we report on the energy spectrum of protons of albedo origin measured by the instruments NINA and NINA-2 at different geomagnetic locations, and the behaviour of the proton flux as a function of altitude out of the South Atlantic Anomaly. The instrument NINA was used on board the satellite Resurs-01-N4 between 1998 and 1999, at an altitude of about 830 km. The NINA-2 apparatus, on board the satellite MITA, was put into orbit in July 2000, at an altitude of about 450 km. A detailed understanding of the fluxes of charged particles in near Earth orbit is important to reach an accurate theoretical description of the Earth’s magnetic field, but also as input for the calculation of the back-ground for scientific instruments aboard satellites, like the future AGILE and GLAST <font face="Symbol">g</font> astronomy telescopes.<br><br><b>Key words.</b> Magnetospheric physics (energetic particles, trapped; instruments and techniques)