Climatic Research Unit : Papers

CRUST: Climatic Research Unit Standardisation of Tree-ring data

Thomas M. Melvin and Keith R. Briffa


CRUST (Climatic Research Unit Standardisation of Tree-ring data) is a computer program for the production of chronologies representing the variance of tree-growth over time. The innovative aspect of this program is the ability to apply various versions of "Signal-Free Regional Chronology Standardisation" (SF RCS) to different types of tree-ring data. The program includes options to use some earlier standardisation methods and procedures, many of which were borrowed from ARSTAN (written and maintained by Ed Cook and Paul Krusic, available from the LDEO Tree Ring Research Laboratory software page).


Further information about these papers is available here.

Program Documentation

The document CRUST.pdf describes how to use the program; navigating the menu system, producing and saving chronologies. The SF RCS is described in the paper Melvin2013_RCS1.pdf and supplementary Melvin2013_RCS1_sup.pdf. The CRUST_readme.pdf contains additional information.

Source Code

Via github

Via the CRU website

The Fortran source code along with a 'makefile' is contained in the 'f90' sub-directory from which the program can be compiled. Pre-compiled executable versions of the program for LINUX and WINDOWS are contained in the CRUST directory. Clicking the executable file should run the program, otherwise it can be run from the command (or DOS) prompt from the CRUST directory. Both github and the zip file also contain a 'data' directory which contains some sample TRW measurement data and pith offsets (described in Melvin 2004, unpublished PhD thesis available here).

Compilation and Portability

The program is written in standard Fortran 90, i.e. avoiding manufacturer specific methods. As such it should compile on all available Fortran 90 compilers. The program has been developed using open source software; on LINUX using the gfortran compiler and DISLIN graphics. The program will also compile on Windows using the MINGW software (with the gfortran option installed) and DISLIN graphics although it is necessary to ensure that the underlying X11 libraries required by DISLIN are available. The program consists of a small 'program' and a number of separate modules which need to be compiled separately and linked. There is a 'makefile' to perform this compilation with the option to select LINUX or WINDOWS. Compilation takes place in the sub-directory 'f90' which contains the makefile. The program has also been compiled on MacOSX (thanks to Paul Krusic but at this time we do not have a standard procedure to perform this in a general environment.

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