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Trapped Radiation ENvironment model Development

Frequently Asked Questions

[ Introduction | General questions | Technical questions | Appendix ]


    This list provides a source of answers to commonly (and some uncommonly) asked questions regarding the use of the UNILIB Library . This list is roughly divided into two categories: general questions and technical questions.

    The latest version of this FAQ page can always be found at If you have suggestions and comments please send an e-mail message to

    The information on this page and the subsequent ones is only related to versions of Unilib up to 2.09.
    Please check for more recent update.

General questions

    G.01 What is the purpose of the library ?
    G.02 Where to find the UNILIB library and documentation ?
    G.03 Who is using the UNILIB library ?
    G.04 How to install the IRI model ?
    G.05 Which are the coordinates and units used ?
    G.06 How to start using the UNILIB library ?
    G.07 Does a similar software or library exist ?
    G.08 How is defined a drift shell ?
    G.09 How to quickly evaluate the capabilities of the UNILIB library ?

Technical questions

    T.01 How to link the UNILIB library ?
    T.02 Why is the object IRIS12 not resolved ?
    T.03 How to customize the magnetic field model used by the library ?
    T.04 Why are Roederer's L* and McIlwain's L parameters different ?
    T.05 How to pass correctly the subroutine arguments in IDL ?
    T.06 What is the precision of the field line tracing algorithm ?
    T.07 Which subroutines are mandatory ?
    T.08 How to link the library in IDL/PV-WAVE ?
    T.09 What about a Linux version of the library ?
    T.10 How to call the library from Win32 application ?


Reported bugs

    26-Aug-97, v1.05, R.01: Anomalous return of subroutine UD310 with error code -41108
    27-Aug-97, v1.05, UT985: Malfunction when field line extended to foot points
    10-Sep-97, v1.06, R.02: Erroneous behaviour of most of the external magnetic field models
    24-Oct-97, v1.07, UT550: Erroneous behaviour of the coordinate transformations relative to GSM and MAG coordinate systems
    18-Dec-97, v1.11, R.03: Malfunction of subroutine UF426
    14-Dec-98, v2.00, UL242: Lack of accuracy for low values of I
    20-Jan-98, v2.00, UD315 and UD327: Error in the interpolation algorithm and inaccurate evaluation of the point with the lowest altitude