SCECcode/bbp: Broadband Platform Release v22.4.0

The SCEC BBP 22.4 is a full release of the Broadband Platform and includes a significant number of new capabilities and improvements added since the last release of the BBP in June 2019. Below is a brief list of the major improvements and modifications included in this release of the Broadband Platform since version 19.4.0:

• Included multi-segment rupture support for GP, SDSU, Irikura 1, Irikura 2, and Song simulation methods. Currently provided multi-segment validation events are Landers, Ridgecrest 19C, and San Simeon.
• Updated GP low-frequency module (jbsim) to perform time-shifting in the time domain instead of frequency domain. This avoids calculating numerous FFTs and results in a significant processing speedup of 10x, and benefits all simulation modules that use the GP low-frequency code.
• Modified UCSB simulation method to include support for double corner frequency (DCF)
• Included FAS validation module that produces FAS Goodness-of-Fitness plots, for a better seismological interpretation of the results. This is in addition to the PSA validation that is the main metric for design in engineering.
• Added Green's Functions and validation events for the Southern Walker Lane region (Southern Sierra Nevada) of California. Validation events include the 2019 Ridgecrest sequence.
• Expanded the GP GoF module to include a Vs30 GoF plot (similar to the distance and map GoF plots) that can be used to show GoF bias related to stations' Vs30s.
• Updated the GP rupture generator to genslip-5.5.2 and the high-frequency code to hb_high_6.0.5.

All new Broadband Platform users should work with this new version of the Broadband Platform. Existing BBP users are encouraged to upgrade to this latest release of the SCEC Broadband Platform, unless they need to reproduce results produced by a previous version. For more information about the Broadband Platform, or details on the new capabilities of BBP 22.4.0, please refer to the Broadband Platform documentation available on BBP's GitHub wiki pages. Should you have any questions about the installation or operation of the BBP, please do not hesitate to contact the SCEC software development group at software@scec.org.