The current UCVM maintained documentation is posted on github at:
Official Version of UCVM
The current (May 2018) official release of UCVM is UCVM v17.1 which is the last release of the C-language version of UCVM. This can be obtained by cloning the UCVMC github repository. The UCVMP (Python language version of UCVM) release is under review, but is not currently used for research purposes.
Naming of CVMs
Velocity Models that can be accessed through the UCVM interface are identify by a scientific name, and also by an internal UCVM short identifier that is used to identify the velocity model when using UCVM. A description of available velocity models, and their UCVM identifiers is posted here:
As an example, the scientific name CVM-S4.26 refers to a version of CVM-S4 that was developed using full 3D tomography by Po Chen and En-Jui Lee. It has a high min Vs (about 900m/s) and it defines Vp, Vs, and rho on a 500 meter spaced grid. It has no background model, and it is only defined to about 50km. The internal UCVM short identifier for this model is "cvms5".
Velocity models can be selected during installation of UCVM, so not all UCVM installations will have access to all models.
Interpolation of Models Defined on Regular Grid
For discrete models like CVM-S4.26, which is defined on a 500m grid, UCVM uses trilnear interpolation to determine material properties between grid points.
UCVM Software Installation Options
Before you can query CVM-S4.26, UCVM must be built and installed on a Linux computer, such as USC HPC research computing center. If you are used to building open-source software on Linux computers, then they may be able to work through the installation process described on the UCVM github wiki.
We created a Virtual Box installation of UCVM which enables users to query common southern California Velocity models (CVM-S4, and CVM-S4.26) on a Mac. This virtual box image is posted it on a SCEC software workshop page Software_Workshop_2018.