1、BSI Standards PublicationBS ISO 17520:2016Space environment (naturaland artificial) Cosmic rayand solar energetic particlepenetration inward themagnetosphere Method ofdetermination of the effectivevertical cut-off rigidityBS ISO 17520:2016 BRITISH STANDARDNational forewordThis British Standard is th
2、e UK implementation of ISO 17520:2016.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/68, Space systems and operations.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the
3、 necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 84644 1ICS 49.140Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard wa
4、s published under the authority of theStandards Policy and Strategy Committee on 30 April 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 17520:2016 ISO 2016Space environment (natural and artificial) Cosmic ray and solar energetic particle penetration inward the
5、 magnetosphere Method of determination of the effective vertical cut-off rigiditySystmes spatiaux (naturel et artificiel) Rayons cosmiques et pntration de particule nergtique solaire dans la magntosphre Mthode de dtermination de la rigidit de coupure verticale effectiveINTERNATIONAL STANDARDISO17520
6、First edition2016-04-01Reference numberISO 17520:2016(E)BS ISO 17520:2016ISO 17520:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise
7、 in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de
8、 Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 17520:2016ISO 17520:2016(E)Foreword ivIntroduction v1 Scope . 12 Terms and definitions . 13 General concepts and assumptions 33.1 Determination of effective vertical cut
9、-off rigidity 33.2 Models of the employed geomagnetic field 33.3 Effective vertical cut-off rigidity databases (libraries). 43.4 Method for effective vertical cut-off data generalization . 44 Model requirements . 44.1 General . 44.2 Parameterization . 4Annex A (informative) Effective vertical cut-of
10、f determination procedure . 5Annex B (informative) Presentation of the results 6Annex C (informative) Method for effective vertical cut-off data generalization for different conditions . 7Bibliography .11 ISO 2016 All rights reserved iiiContents PageBS ISO 17520:2016ISO 17520:2016(E)ForewordISO (the
11、 International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committe
12、e has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechni
13、cal standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in
14、 accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. D
15、etails of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an
16、 endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee r
17、esponsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations.iv ISO 2016 All rights reservedBS ISO 17520:2016ISO 17520:2016(E)IntroductionThis International Standard describes principal requirements for determination of the effective vertic
18、al cut-off rigidity of penetration of charged particles inward the Earths magnetosphere. This International Standard establishes procedure for calculation of the effective vertical cut-off rigidities for altitude, geographical coordinates (latitude and longitude), and for conditions of geomagnetic d
19、isturbances described by the Kp-index, as well as for local time. The model that satisfies these requirements is described in the Annex through a series of examples. This International Standard is intended for estimation of penetration into the Earths magnetosphere by charged particle fluxes from in
20、terplanetary space, which is important for developing and testing of influence to hardware and biological objects onboard spacecraft and orbital stations. Procedures for performing simplified calculations of rigidities are proposed. ISO 2016 All rights reserved vBS ISO 17520:2016BS ISO 17520:2016Spa
21、ce environment (natural and artificial) Cosmic ray and solar energetic particle penetration inward the magnetosphere Method of determination of the effective vertical cut-off rigidity1 ScopeThis International Standard describes the effective vertical cut-off rigidities of charged particles for near-
22、Earth space and establishes principal requirements for their calculation. In Annex A, the calculation technique is verified using a typical example. This International Standard can be used to develop calculation techniques based on different models of Earths geomagnetic field.1The techniques are use
23、ful for determination of penetrating into the Earths magnetosphere by charged particle fluxes, as well as for test and estimations of the impact on spacecraft and other equipment in the near-Earth space.This International Standard is valid for calculating the particle penetration by any of the compo
24、nent of interplanetary charged particles (Galactic, Solar, and Anomalous) with rigidities above 0,2 GV. The main goals of the present standardization for the determination of the effective vertical geomagnetic cut-off rigidities are as follows: provide an unambiguous procedure for calculation of the
25、 cut-off rigidities inside of the Earths magnetosphere reflecting dependences on geomagnetic disturbances and local time; provide means of estimation of the impact of charged particle fluxes in interpretation and analysis of space experiments; provide efficient calculations of the transmission funct
26、ions of low-altitude orbits of spacecraft and manned space-station; determine impact of solar energetic particle flux on spacecraft instrumentation and astronauts using results of independent online measurement of interplanetary particle fluxes.2 Terms and definitionsFor the purposes of this documen
27、t, the following terms and definitions apply.2.1internal (main) magnetic fieldmagnetic field produced by the sources inside the Earths core Note 1 to entry: See ISO 16695.Note 2 to entry: It can be presented by the International Geomagnetic Reference Field (IGRF) model.2.2International Geomagnetic R
28、eference Field modelIGRF modelgeomagnetic reference field in the form of a series of spherical harmonic functionsNote 1 to entry: See Reference 2.Note 2 to entry: The expansion coefficients undergo very slight changes in time.Note 3 to entry: The International Association of Geomagnetism and Aeronom
29、y (IAGA) is responsible for IGRF model development and modifications and approves its coefficients every five years. The internal magnetic field is not the subject of this International Standard.INTERNATIONAL STANDARD ISO 17520:2016(E) ISO 2016 All rights reserved 1BS ISO 17520:2016ISO 17520:2016(E)
30、2.3external (magnetospheric) magnetic fieldmagnetic field produced by magnetospheric sourcesNote 1 to entry: It can be described by different models, e.g. Tsyganenko-893and more recent models.452.4Tsyganenko-89 geomagnetic field modelmodel described in Reference SOURCE: 32.5Geomagnetic fieldsum of i
31、nternal and external magnetic fields2.6particle charge Zcharge Z of a particle is equal to +ne, (n = 1, 2, 3,.), where e is the value of electron charge (1,60 1019C).2.7particle magnetic rigiditymagnetic rigidity of particle R is related to particle momentum p and its charge by:R = pc/Zwhere c is th
32、e speed of light, and Z is the charge of a particleNote 1 to entry: The magnetic rigidity of protons and nuclei is related to the particles energy as RAZEE M=+( 20)where E is the kinetic energy in GeV/u, A is the particles mass in amu, and M0is the rest mass of proton equal to 0,931 GeV.2.8cut-off r
33、igiditylocation of a transition, in rigidity space, from allowed to forbidden trajectories as rigidity is decreasing2.9lower cut-off rigidityRLaccess of particles of all rigidity values lower than the lower cut-off rigidity is forbidden for penetration from outside of the Earths magnetic fieldNote 1
34、 to entry: RLis the calculated lowest cut-off value, i.e. the rigidity value of the lowest allowed/forbidden transition obtained in computer simulations.2.10main (upper) cut-off rigidityRUaccess of particles of all rigidity values higher than the main cut-off rigidity is allowed for penetration from
35、 outside of the Earths magnetic fieldNote 1 to entry: RUis the rigidity value of the calculated upper cut-off value, i.e. the rigidity value of the highest allowed/forbidden transition obtained in computer simulations.2.11penumbrarigidity range lying between the main (upper) and the lower cut-off ri
36、gidities2 ISO 2016 All rights reservedBS ISO 17520:2016ISO 17520:2016(E)2.12effective cut-off rigidityRefftotal effect of the penumbral structure in a given direction may be represented for a number of purposes, by the “effective cut-off rigidity”, a single numerical value which specifies the equiva
37、lent total accessible cosmic radiation within the penumbra in a specific direction2.13effective vertical cut-off rigidityEVRCeffective cut-off rigidity value for a particle arriving to a fixed point in the vertical direction (radially to the centre of the Earth)2.14index of magnetosphere disturbance
38、Kthree-hour quasi-logarithmic local index of geomagnetic activity relative to on assumed quiet-day curve for a specific recording siteNote 1 to entry: The range is from zero to nine. The K index measures the deviation of the most disturbed horizontal component.2.15Kp-indexthree-hour planetary geomag
39、netic index of activity based on the K index from 13 stations distributed around the worldNote 1 to entry: The Kp-index is originally derived at GeoForschungsZentrum in Germany. The web address should be http:/www.gfzpotsdam.de/en/research/organizationalunits/departments/department-2/earthsmagnetic-
40、field. It is also available at www.swpc.noaa.gov.2.16attenuation quotient(R0,Kp,T)determines how much the vertical cut-off rigidity value in a real geomagnetic field for a given Kp-index, at a local time T, decreased relative to values calculated with the IGRF model (R0)Note 1 to entry: Some of thes
41、e terms are also defined in Reference 6.3 General concepts and assumptions3.1 Determination of effective vertical cut-off rigidityThe geomagnetic cut-off rigidities are determined by tracing particle trajectories in the geomagnetic field. For a more detailed description of the method, see Annex A an
42、d References 7 and 8. The method determines the trajectory of negatively charged particles emitted from the given coordinate point in the vertical direction in an effort to estimate whether the particle escapes the magnetosphere. As a result of tests of particles with different rigidities, it is pos
43、sible to determine upper and lower rigidities for given magnetospheric conditions. From these data, the effective value of the vertical cut-off rigidity can be determined.The calculation technique should be detailed enough to determine the effective cut-off values with an accuracy better than 2 %. R
44、esults of application of this type of calculation technique to IGRF data for a given set of initial points are presented in Table C.1.3.2 Models of the employed geomagnetic fieldThe models for the geomagnetic field should reflect the changes of the internal field (IGRF model for each five-year perio
45、d), as well as changes of the external (magnetosphere) magnetic field caused by ISO 2016 All rights reserved 3BS ISO 17520:2016ISO 17520:2016(E)current flowing in the magnetosphere and on its surface. This International Standard allows the use of all of present day models (Tsyganenko or other extens
46、ions).3.3 Effective vertical cut-off rigidity databases (libraries)In addition to direct computation of cut-off rigidities, the world grids of calculated values of vertical cut-off rigidities can be used to evaluate the radiation conditions for different spacecraft and manned station orbits. Sometim
47、es, that kind of database is calculated for many different levels of magnetosphere disturbances and different local (or universal) time groups. These databases are put together in a “library”.9That kind of “library”, together with the associated cut-off rigidity interpolation software, provides a to
48、ol for general use in space physics applications.3.4 Method for effective vertical cut-off data generalizationIn these libraries, the effective vertical cut-off rigidity world grids are tabulated versus the discounted magnetosphere disturbance levels and local (or universal) time. Spacecraft and man
49、ned station orbits are variable, which means that the disturbance levels are not integers, but are subdivided. The same is true for the local (or universal) time. Therefore, it is not convenient to tabulate the detailed library needed to store all this data. The sheer size of the tabulation would make it unusable. However, the content of the library can be generalized in the form of a unique world grid of effective vertical cut-off rigidities calculated with the IGRF magnetosphere model for altit
