38.3 NOR2DD

originally by Brian Baptie, BGS

This program produces input for the Double Difference Program hypoDD [Waldhauser and Ellsworth, 2002; Waldhauser, 2001] from Nordic and STATION0.HYP files. The program also converts back from hypoDD output to Nordic format. The Nordic file name is entered when the program starts.

The program gives the option to use and P and S-phases, or only P or S, which means first arrivals (and not Pg, Pn, etc). When first arrivals only are used, the user can enter minimum distance for which Pn/Sn are valid, and maximum distance where Pg/Sg are expected. This has to be chosen based on the model and observations. For example, one may not want to include Pg when it appears as first arrival at 250 km distance, or one should not include Pn observed on continental crust at 25 km distance.

The user also can enter specific station weights.

The output files created are:

phase.dat : phase input data
station.dat : station coordinates

hypoDD is available from: http://geopubs.wr.usgs.gov/open-file/of01-113/