Strike Code Page: version 3.2

• PDF full text version (1.1 Mb)

It is based on Groom-Bailey tensor decomposition. It currently solves for the electric effects of the galvanic-charges only. Tests with including magnetic effects (see McNeice and Jones, 2001) show the inherent instability of trying to solve for so many parameters.

Documentation can be read here. An example input data file from a single station can be downloaded from here, and an output file for one-decade-width bands from here.

The input data must be in J-format. The program will either read in a single data file (for single-site mode), or read in a list of data files (for multi-site mode). The user specifies frequency bands to operate on, and an overlap. Accordingly, mixed datasets are permitted with data at different frequencies at different sites.

IMPORTANT: In version 19 the main minimization routine E04UPF was replaced by E04UNF. If you purchase version 19 or higher I can provide version 16 routines for comparison purposes.

We have attempted to find alternative freeware routines for the minimization search, but we have found the NAG routines to be stable and fast compared to any others. Also, the NAG routine is the only one we know of that permits the user to supply the Jacobian and the Hermetian matrices, as well as have bounds on the model parameters. [We would be willing to work with someone who is prepared to test out other routines.]

We ask you to do this not to restrict use of strike in any way, but to try to ensure that we know who is using it so that you will be informed immediately of bugs and new releases, and to try to ensure that it is freely available to those who use it for free. Commercial use is certainly encouraged, but it is reasonable that if strike is used for profit, then there has to be a sharing of that profit.

Conditions for the use of the McNeice-Jones multi-site, multi-frequency magnetotelluric tensor decomposition code.

1. I accept the McNeice-Jones multi-site, multi-frequency magnetotelluric tensor decomposition code, hereinafter called "strike", on a caveat emptor basis.
2. I will use strike for non-profit purposes only.
3. I will not accept any payment for use of strike.
4. I will not give strike to any other person.
5. I will inform the authors of strike, Gary McNeice and Alan Jones, of any coding errors that I find.
6. I will inform the authors of strike, Gary McNeice and Alan Jones, of any improvements and additions that I make.
7. I will acknowledge the use of strike in any publications and presentations I write or give in which I present results based on strike-based decomposition or decomposed data.
8. I understand that the current version of strike, v3.2, uses NAG routines that I have to provide myself.

Signed:____________________________________ Date:_________________

Address:
Institute/Dept./Group:
Organization:
Street Address:
City:
Province/State:
Postal Code:
Country:

Email address:

Authors:

---

Alan G Jones / 30 April 2001 / ajones@cg.NRCan.gc.ca