ISO/TS 16457:2009

Space systems — Space environment (natural and artificial) — The Earth's ionosphere model: international reference ionosphere (IRI) model and extensions to the plasmasphere

ISO/TS 16457:2009 provides guidance to potential users for the specification of the global distribution of ionosphere densities and temperatures, as well as the total content of electrons in the height interval from 50 km to 1 500 km. It includes and explains several options for a plasmaspheric extension of the model, embracing the geographical area between latitudes of 80°S and 80°N and longitudes of 0°E to 360°E, for any time of day, any day of year, and various solar and magnetic activity conditions.

Systèmes spatiaux — Environnement spatial (naturel et artificiel) — Modèle de l'ionosphère de la Terre: modèle de l'ionosphère internationale de référence (IRI) et extensions à la plasmasphère

General Information

• Status: Withdrawn
• Publication Date: 02-Feb-2009
• Withdrawal Date: 02-Feb-2009
• ICS: 07.060 - Geology. Meteorology. Hydrology
• ICS: 49.140 - Space systems and operations
• Technical Committee: ISO/TC 20/SC 14 - Space systems and operations
• Drafting Committee: ISO/TC 20/SC 14/WG 4 - Space environment (natural and artificial)
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 10-Apr-2014

Relations

• Revised: ISO 16457:2014 - Space systems — Space environment (natural and artificial) — The Earth's ionosphere model: international reference ionosphere (IRI) model and extensions to the plasmasphere
• Effective Date: 23-Feb-2012

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 16457
First edition
2009-02-15
Space systems — Space environment
(natural and artificial) — The Earth's
ionosphere model: international
reference ionosphere (IRI) model and
extensions to the plasmasphere
Systèmes spatiaux — Environnement spatial (naturel et artificiel) —
Modèle de l'ionosphère de la Terre: modèle de l'ionosphère
internationale de référence (IRI) et extensions à la plasmasphère
Reference number
ISO/TS 16457:2009(E)
ISO 2009
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ISO/TS 16457:2009(E)
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ii © ISO 2009 – All rights reserved
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ISO/TS 16457:2009(E)
Foreword

ISO (the 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 committee has been

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International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

In other circumstances, particularly when there is an urgent market requirement for such documents, a

technical committee may decide to publish other types of document:

— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in

an ISO working group and is accepted for publication if it is approved by more than 50 % of the members

of the parent committee casting a vote;

— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical

committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting

a vote.

An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a

further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is

confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an

International Standard or be withdrawn.

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.

ISO/TS 16457 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee

SC 14, Space systems and operations.
© ISO 2009 – All rights reserved iii
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ISO/TS 16457:2009(E)
Introduction

This Technical Specification provides guidelines for specifying the global distribution of ionospheric electron

density, electron temperature, ion temperature, ion composition, and total electron content and the extension

of these parameters into the plasmasphere. The model recommended for the representation of these

parameters in the ionosphere is the international reference ionosphere (IRI).

IRI is an international project sponsored by the Committee on Space Research (COSPAR) and the

International Union of Radio Science (URSI). These organizations formed a working group in the late 1960s to

produce an empirical standard model of the ionosphere based on all available data sources. Several steadily

improved editions of the model have been released (References [18], [19], [20], [5], [6], [1], [2], [3]).

For a given location, time and date, IRI describes the monthly averages of electron density, electron

+ + + + + +

temperature, ion temperature, and the percentage of O , H , He , N , NO , O and cluster ions in the altitude

range from 50 km to 1 500 km. In addition, IRI provides the electron content by numerically integrating over

the electron density height profile within user-provided integral boundaries. IRI is a climatological model

describing monthly average conditions. The major data sources for building the IRI model are the worldwide

network of ionosondes, the powerful incoherent scatter radars, and the topside sounders and in situ

instruments flown on several satellites and rockets. This Technical Specification also presents several models

that can be used to extend the IRI model to plasmasphere altitudes.

The IRI model is the de facto world-wide model for the ionosphere under COSPAR and URSI patronage and

is a continuously evolving model that improves as new data become available. This Technical Specification is

an important initial step towards developing a common framework for an International Standard of the

ionosphere and plasmasphere.

1) The homepage of the IRI project is http://IRI.gsfc.nasa.gov. The IRI program is provided as a FORTRAN computer

code for use on UNIX, VAX and PC-Windows systems. The code can be downloaded from the IRI homepage. The IRI

homepage also provides access to an interactive system for computing and plotting IRI parameters online and to a special

PC Windows version with multiple plotting options developed at the University of Massachusetts Lowell.

iv © ISO 2009 – All rights reserved
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TECHNICAL SPECIFICATION ISO/TS 16457:2009(E)
Space systems — Space environment (natural and artificial) —
The Earth's ionosphere model: international reference
ionosphere (IRI) model and extensions to the plasmasphere
1 Scope

This Technical Specification provides guidance to potential users for the specification of the global distribution

of ionosphere densities and temperatures, as well as the total content of electrons in the height interval from

65 km to 1 500 km. It includes and explains several options for a plasmaspheric extension of the model,

embracing the geographical area between latitudes of 80°S and 80°N and longitudes of 0°E to 360°E, for any

time of day, any day of year, and various solar and magnetic activity conditions.

2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
ionosphere

region of the Earth's atmosphere in the height interval from approximately 50 km to approximately 1 500 km

containing partially ionized cold plasma
2.2
plasmasphere
−3 +

torus of cold, relatively dense (> 10 cm ) plasma of mostly H in the inner magnetosphere, which is trapped

on the Earth's magnetic field lines and thus co-rotates with the Earth

NOTE Here, cold plasma is considered to have an energy of between a few electronvolts and a few dozen

electronvolts.
2.3
plasmapause

outward boundary of the plasmasphere located at between two and six earth radii from the centre of the Earth

and formed by geomagnetic field lines where the plasma density drops by a factor of 10 or more across a

range of L-shells of as little as 0,1

NOTE The L-shell is a parameter describing a particular set of planetary magnetic field lines, often describing the set

of magnetic field lines which cross the Earth's magnetic equator at a number of Earth radii equal to the L-value, e.g. “L = 2”

describes the set of the Earth's magnetic field lines which cross the Earth's magnetic equator two Earth radii from the

centre of the Earth.
2.4
solar activity

series of processes occurring in the Sun's atmosphere which affect the interplanetary space and the Earth

NOTE The level of solar activity is characterized by indices.
© ISO 2009 – All rights reserved PROOF/ÉPREUVE 1
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ISO/TS 16457:2009(E)
2.5
ionospheric storm

storm lasting about a day, documented by depressions and/or enhancements of the ionospheric electron

density during various phases of the storm

NOTE Ionospheric storms are the ultimate result of solar flares or coronal mass ejections, which produce large

variations in the particle and electromagnetic radiation that hit Earth's magnetosphere and ionosphere, as well as large-

scale changes in the global neutral wind, composition and temperature.
2.6
sunspot number
number of sunspots and sunspot groups determined daily
2.7
R12
twelve-month-running mean monthly sunspot number
2.8
kp index

planetary three-hour index of geomagnetic activity characterizing the disturbance in the Earth's magnetic field

measured at ground level over three-hour universal time (UT) intervals

NOTE The index scale is uneven quasi-logarithmic and expressed in numbers from 0 to 9.

2.9
ap index

three-hour UT amplitude index of geomagnetic variation linearized equivalent to kp

NOTE The index scale is linear and expressed in numbers from 1 to 400.
2.10
total electron content
TEC
integral number of electrons in a unit-area column through the ionosphere
16 −2
NOTE It is expressed in units of 10 electrons m (TECU).
3 Abbreviated terms
IRI international reference ionosphere
ELF extremely low frequency
VLF very low frequency (3 kHz to 30 kHz)
LF low frequency (30 kHz to 300 kHz)
MF medium frequency (300 kHz to 3 MHz)
HF high frequency (3 MHz to 30 MHz)
VHF very high frequency (30 MHz to 300 MHz)
UHF ultra high frequency (300 MHz to 3 000 MHz)
2 © ISO 2009 – All rights reserved
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ISO/TS 16457:2009(E)
4 General considerations

This model for the representation of the ionospheric and plasmaspheric plasma parameters is important to a

wide spectrum of applications. Electromagnetic waves travelling through the ionized plasma at the Earth’s

environment experience retardation and refraction effects. A remote sensing technique relying on signals

traversing the ionosphere and plasmasphere therefore needs to account for the ionosphere-plasmasphere

influence in its data analysis. Applications can be found in the disciplines of altimetry, radio astronomy,

satellite communication, navigation and orbit determination.

For high frequency radio communication, a good knowledge of the heights and plasma frequencies of the

reflective layers of the ionosphere and the plasmasphere is critical for continuous and high-quality radio

reception. High frequency communication remains of great importance in many remote locations of the globe

and for some specialized military applications. The model helps estimate the effect of charged particles on

technical devices in the Earth's environment and defines the ionosphere-plasmasphere operational

environment for existing and future systems of radio communication, radio navigation and other relevant radio

technologies in the medium and high frequency ranges.
5 Applicability

There are a multitude of operational usages for ionospheric models, of which the most important are outlined

in this clause. Operators of certain navigational satellite systems such as GPS (U.S.A.), GLONASS (Russia)

and GALILEO (Europe) require ionospheric predictions to mitigate losses of navigation signal phase and/or

amplitude lock, as well as to maintain accurate orbit determination for all their satellites. Radio and television

operators using MF, HF, VHF, UHF satellite or ground stations require ionospheric parameters for efficient

communications and for reducing interferences. Space weather forecasters have a great need for accurate

ionospheric models to provide their customers with reliable and up-to-the-minute we

...