EM3DVP：用于 3D 地电磁建模和反演 的可视化软件包_MATLAB_代码_下载

# EM3DVP: > a Visual Package for 3D Geo-Electromagnetic modeling and inversion EM3DVP is a package of Matlab scripts. Its primary goal is to provide the users of EM methods an easy-to-use and (hopefully) comprehensive GUI to prepare the input model, data and parameter files for the 3D inversion codes, as well as an interface to plot the result models and responses. Note that this apparently works only for structured mesh.  ## something like a disclaimer I wrote the package just for the convenience of myself and my colleagues/students in our group. Those who want to try this script are free to use it on academic/educational cases. But of course, I cannot guarantee the script to be working properly and calculating correctly (although I wish so). Have you any questions or suggestions, please feel free to contact me (but don't you expect that I will reply quickly!). ## HOW TO GET IT ``` git clone https://github.com/dong-hao/EM3DVP/ your_local_folder ``` ## UNITS The internal unit here is the 'practical' one, as used in most survey files (mV/km/nT) for E/B. To convert to Ohm (used by Weerachai's code) one needs to multiply the values by ~796. To convert to V/m/T (used by ModEM) one needs to multiply the values by 0.001 ## SIGN The internal time harmonic sign convention is plus (+), or exp(i\omega t). Be careful when you need to deal with data with (-) convention. ## ERRORS Currently the internal error here is standard deviation, it worths noting that most of the survey file formats use variance (this code used variances as well before 2017). WARNING: I haven't touched that part for WSINV3D format, there must be some potential bugs lurking somewhere. ## HOW TO GET UPDATED ``` cd to_you_local_folder git pull ``` ## MISC NOTES I decided to use a new system of version as the package name keeps going longer... Now I simply call it EM3DVP... Also, I tried to remove any rude words within my comments... If you found some part of the comments uncomfortable, please let me know. ## Release History * 0.0.7 * a couple of minor fixes in the profile section interface - fixed the output for the xyz and loc files. * 0.0.6 * a couple of bug fixes when adding topography/bathymetry to the model - fixed a bug when locating which mesh grid a site is, and correct the site elevation so that the elevation is consistent with the model air/sea layer depth. Another quick fix is for the callback when one inputs the centre/reference point for the projection. Also modified the site projection strategy to use the median location of the stations as the center/reference coordinate when the study region is small enough (< 1 by 1 degree). * 0.0.5 * a couple of new features - now supports "Anisotrophy" features by generating high/low resistivity fine stripes, which cannot be resolved by isotropic modelling. Also updated a long forgoten feature to extract 1D layered resistivity at a given surface point of 3D model. * 0.0.4 * bug fixes and a couple of features - adding the function to build a tear layer with a boundary file; adding the option to export the induction vector information to be plotted with third party programes (e.g. GMT); the program now display the RMS in a different manner - the RMSs for tipper and impedance are now displayed in separate values. * 0.0.3 * fixed an old (and purely cosmetic) bug in displaying the errorbar for impedance phases. This was not of importance as it did not affect the actual errorbar in the outputted data. * 0.0.2 * some minor modifications mostly for dealing with poorly formatted data and model files * 0.0.1 * initial implement ## Contact DONG Hao – donghao@cugb.edu.cn China University of Geosciences, Beijing Distributed under the GPL v3 license. See ``LICENSE`` for more information. [https://github.com/dong-hao/EM3DVP] ## Contributing Those who are willing to contribute are welcomed to try - but I probably won't have the time to review the commits frequently (not that I would expect there will be any). 1. Fork it (<https://github.com/dong-hao/EM3DVP/fork>) 2. Create your feature branch (`git checkout -b feature/somename`) 3. Commit your changes (`git commit -am 'Add some features'`) 4. Push to the branch (`git push origin feature/somename`) 5. Create a new Pull Request - lather, rinse, repeat ## Commercial Usage Commercial usage is not forbidden by the license - but you are recommended to contact Dr. Naser Meqbel for his more advanced GUI. You will get a more robust software with more useful features. Visit his website: http://www.consulting-geo.com for details. I should ask him for affiliate commission (reads: money) for posting his link here! ## Getting Started ### a. prerequisite Modelling: You can begin your modelling from (literally) scratch with EM3DVP. However, if you plan to include topography/bathymetry in your model, you will need digital elevation data in .xyz format (lon lat elev) for EM3DVP to read. If you have designed your site distribution in other software, you will also have to convert them into xyz format (Northing Easting Elevation). Pre-existed ModEM/WSINV3D/WinGlink Models can be imported. inversion: you will need your MT field data files (.EDI files) as well as the digital elevation file or model files, as described in modelling part. ### b. prepare input files for forward/inversion load data: click the "Load EDIs" button on the "model creating interface" to load EDI files in a GUI file manager. Alternately, you can click the "IMPORT" pop-up menu to import ModEM or WSINV3D data. Once you loaded the data, the sites will be automatically projected from Geological coordinates using UTM projection. A default model will also be automatically generated for the sites. in "data settings" interface: site projection: you can manually select the projection "zero point" using "fixed" radio button and arbitrary LAT/LON as project centre. If "automatic" is selected, the middle value of LAT/LON from all sites will be used as the project centre. data selection: you can select data responses used in forward/inversion in "data select" box. tick "Zxx&Zyy" for diagonal impedances, "Zxy&Zyx" for off-diagonal impedances, and "Tx&Ty" for tippers. Select the period range with the upper and lower bond after "Periods:" in "data select" box. Set the number of periods per octave after "Periods/Octave:". error setting: you can manually set data error with the "fixed" radio button in "data error" box. Given error will be used for diagonal, off-diagonal impedances and tipper respectively. If "from data" is selected, original data error will be used. in "model generation" interface model parameter: you can manually set the model mesh parameters in "model generation" interface X,Y,Z are the Northing, Easting and Vertical coordinates respectively. By hitting "generate", a new homogeneous half space model will be generated using the following parameters, as described below. x block width: width of the x blocks within the core area. x outcore blocks: number of x blocks out of the core area. x outcore step: increasing step for x blocks out of the core. y block width: width of the y blocks within the core area. y outcore blocks: number of y blocks out of the core area. y outcore step: increasing step for y blocks out of the core. y block width: width of the y blocks within the core area. y outcore blocks: number of y blocks out of the core area. y outcore step: increasing step for y blocks out of the core. z first thickness: thickness of the first z layer. z incore step: increasing step for z layers within the core. z incore layers: number of z layers within the core area. z outcore step: increasing step for z layers out of the core. z outcore layers: number of z layers out of the core area. background res.: default resistivity of the generated model. model display