Heagy et al., 2017 Load and Plot Bookpurnong Data

In this example, we load and plot the SkyTEM (2006) and RESOLVE (2008) Bookpurnong data, available at https://storage.googleapis.com/simpeg/bookpurnong/bookpurnong.tar.gz

This is published in

Lindsey J. Heagy, Rowan Cockett, Seogi Kang, Gudni K. Rosenkjaer, Douglas W. Oldenburg, A framework for simulation and inversion in electromagnetics, Computers & Geosciences, Volume 107, 2017, Pages 1-19, ISSN 0098-3004, http://dx.doi.org/10.1016/j.cageo.2017.06.018.

The script and figures are also on figshare: https://doi.org/10.6084/m9.figshare.5107711

This example was updated for SimPEG 0.14.0 on January 31st, 2020 by Joseph Capriotti

Downloading https://storage.googleapis.com/simpeg/bookpurnong/bookpurnong_inversion.tar.gz
   saved to: /home/vsts/work/1/s/examples/20-published/bookpurnong_inversion.tar.gz
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import numpy as np
import matplotlib.pyplot as plt
import h5py
import tarfile
import os
import shutil
from simpeg import utils
import discretize


def download_and_unzip_data(
    url="https://storage.googleapis.com/simpeg/bookpurnong/bookpurnong_inversion.tar.gz",
):
    """
    Download the data from the storage bucket, unzip the tar file, return
    the directory where the data are
    """
    # download the data
    downloads = utils.download(url)

    # directory where the downloaded files are
    directory = downloads.split(".")[0]

    # unzip the tarfile
    tar = tarfile.open(downloads, "r")
    tar.extractall()
    tar.close()

    return downloads, directory


def save_dict_to_hdf5(fname, dictionary):
    """
    Save a dictionary to hdf5
    """
    f = h5py.File(fname, "w")
    for key in dictionary.keys():
        f.create_dataset(key, data=dictionary[key])
    f.close()


def run(plotIt=True, saveIt=False, saveFig=False, cleanup=True):
    """
    Download and plot the Bookpurnong data. Here, we parse the data into a
    dictionary that can be easily saved and loaded into other worflows (for
    later on when we are doing the inversion)

    :param bool plotIt: show the Figures?
    :param bool saveIt: re-save the parsed data?
    :param bool saveFig: save the matplotlib figures?
    :param bool cleanUp: remove the downloaded and saved data?
    """

    downloads, directory = download_and_unzip_data()

    # data are in a directory inside bookpurnong_inversion
    data_directory = os.path.sep.join([directory, "bookpurnong_data"])

    # Load RESOLVE (2008)
    header_resolve = "Survey     Date   Flight      fid  utctime helicopter_easting helicopter_northing gps_height bird_easting bird_northing bird_gpsheight elevation bird_height bird_roll bird_pitch bird_yaw    em[0]    em[1]    em[2]    em[3]    em[4]    em[5]    em[6]    em[7]    em[8]    em[9]   em[10]   em[11]       Line "
    header_resolve = header_resolve.split()
    resolve = np.loadtxt(
        os.path.sep.join([data_directory, "Bookpurnong_Resolve_Exported.XYZ"]),
        skiprows=8,
    )

    # Omit the cross lines
    resolve = resolve[(resolve[:, -1] > 30002) & (resolve[:, -1] < 38000), :]
    dat_header_resolve = "CPI400_F  CPQ400_F  CPI1800_F CPQ1800_F CXI3300_F CXQ3300_F CPI8200_F CPQ8200_F CPI40k_F  CPQ40k_F  CPI140k_F CPQ140k_F "
    dat_header_resolve = dat_header_resolve.split()

    xyz_resolve = resolve[:, 8:11]
    data_resolve = resolve[:, 16:-1]

    # Load SkyTEM (2006)
    fid = open(
        os.path.sep.join(
            [data_directory, "SK655CS_Bookpurnong_ZX_HM_TxInc_newDTM.txt"]
        ),
        "rb",
    )
    lines = fid.readlines()
    fid.close()
    header_skytem = lines[0].split()
    info_skytem = []
    data_skytem = []
    for line in lines[1:]:
        if len(line.split()) != 65:
            info_skytem.append(np.array(line.split()[:16], dtype="O"))
            data_skytem.append(np.array(line.split()[16 : 16 + 24], dtype="float"))
        else:
            info_skytem.append(np.array(line.split()[:16], dtype="O"))
            data_skytem.append(np.array(line.split()[17 : 17 + 24], dtype="float"))
    info_skytem = np.vstack(info_skytem)
    data_skytem = np.vstack(data_skytem)
    lines_skytem = info_skytem[:, 1].astype(float)
    inds = lines_skytem < 2026
    info_skytem = info_skytem[inds, :]
    data_skytem = data_skytem[inds, :].astype(float)
    xyz_skytem = info_skytem[:, [13, 12]].astype(float)
    lines_skytem = info_skytem[:, 1].astype(float)

    # Load path of Murray River
    river_path = np.loadtxt(os.path.sep.join([directory, "MurrayRiver.txt"]))

    # Plot the data
    nskip = 40
    fig = plt.figure(figsize=(12 * 0.8, 6 * 0.8))
    title = ["Resolve In-phase 400 Hz", r"SkyTEM High moment 156 $\mu$s"]
    ax1 = plt.subplot(121)
    ax2 = plt.subplot(122)
    axs = [ax1, ax2]
    out_re = utils.plot2Ddata(
        xyz_resolve[::nskip, :2],
        data_resolve[::nskip, 0],
        ncontour=100,
        contourOpts={"cmap": "viridis"},
        ax=ax1,
    )
    vmin, vmax = out_re[0].get_clim()
    cb_re = plt.colorbar(
        out_re[0], ticks=np.linspace(vmin, vmax, 3), ax=ax1, fraction=0.046, pad=0.04
    )
    temp_skytem = data_skytem[:, 5].copy()
    temp_skytem[data_skytem[:, 5] > 7e-10] = 7e-10
    out_sky = utils.plot2Ddata(
        xyz_skytem[:, :2],
        temp_skytem,
        ncontour=100,
        contourOpts={"cmap": "viridis", "vmax": 7e-10},
        ax=ax2,
    )
    vmin, vmax = out_sky[0].get_clim()
    cb_sky = plt.colorbar(
        out_sky[0],
        ticks=np.linspace(vmin, vmax, 3),
        ax=ax2,
        format="%.1e",
        fraction=0.046,
        pad=0.04,
    )
    cb_re.set_label("Bz (ppm)")
    cb_sky.set_label("Voltage (V/A-m$^4$)")

    for i, ax in enumerate(axs):
        xticks = [460000, 463000]
        yticks = [6195000, 6198000, 6201000]
        ax.set_xticks(xticks)
        ax.set_yticks(yticks)
        ax.plot(river_path[:, 0], river_path[:, 1], "k", lw=0.5)

        ax.set_aspect("equal")
        if i == 1:
            ax.plot(xyz_skytem[:, 0], xyz_skytem[:, 1], "k.", alpha=0.02, ms=1)
            ax.set_yticklabels([str(" ") for f in yticks])
        else:
            ax.plot(xyz_resolve[:, 0], xyz_resolve[:, 1], "k.", alpha=0.02, ms=1)
            ax.set_yticklabels([str(f) for f in yticks])
            ax.set_ylabel("Northing (m)")
        ax.set_xlabel("Easting (m)")
        ax.set_title(title[i])
    plt.tight_layout()

    if plotIt:
        plt.show()

    if saveFig:
        fig.savefig("bookpurnong_data.png")

    cs, ncx, npad = 1.0, 10.0, 20
    hx = [(cs, ncx), (cs, npad, 1.3)]
    npad = 12
    temp = np.logspace(np.log10(1.0), np.log10(12.0), 19)
    temp_pad = temp[-1] * 1.3 ** np.arange(npad)
    hz = np.r_[temp_pad[::-1], temp[::-1], temp, temp_pad]
    mesh = discretize.CylindricalMesh([hx, 1, hz], "00C")
    active = mesh.cell_centers_z < 0.0

    dobs_re = np.load(os.path.sep.join([directory, "dobs_re_final.npy"]))
    dpred_re = np.load(os.path.sep.join([directory, "dpred_re_final.npy"]))
    mopt_re = np.load(os.path.sep.join([directory, "mopt_re_final.npy"]))

    # Down sample resolve data
    nskip = 40
    inds_resolve = np.r_[np.array(range(0, data_resolve.shape[0] - 1, nskip)), 16730]

    booky_resolve = {
        "data": data_resolve[inds_resolve, :],
        "data_header": dat_header_resolve,
        "line": resolve[:, -1][inds_resolve],
        "xy": xyz_resolve[:, :2][inds_resolve],
        "src_elevation": resolve[:, 12][inds_resolve],
        "ground_elevation": resolve[:, 11][inds_resolve],
        "dobs": dobs_re,
        "dpred": dpred_re,
        "mopt": mopt_re,
        "z": mesh.cell_centers_z[active],
        "frequency_cp": np.r_[382, 1822, 7970, 35920, 130100],
        "frequency_cx": np.r_[3258.0],
        "river_path": river_path,
    }

    area = 314.0
    waveform = np.loadtxt(os.path.sep.join([directory, "skytem_hm.wf"]))
    times = np.loadtxt(os.path.sep.join([directory, "skytem_hm.tc"]))

    booky_skytem = {
        "data": data_skytem,
        "data_header": header_skytem[17 : 17 + 24],
        "line": lines_skytem,
        "xy": xyz_skytem,
        "src_elevation": info_skytem[:, 10].astype(float),
        "ground_elevation": info_skytem[:, 15].astype(float),
        "area": area,
        "radius": np.sqrt(area / np.pi),
        "t0": 0.01004,
        "waveform": waveform,
        "times": times,
    }

    if saveIt:
        save_dict_to_hdf5(
            os.path.sep.join([directory, "booky_resolve.hdf5"]), booky_resolve
        )
        save_dict_to_hdf5(
            os.path.sep.join([directory, "booky_skytem.hdf5"]), booky_skytem
        )

    if cleanup:
        os.remove(downloads)
        shutil.rmtree(directory)


if __name__ == "__main__":
    run(plotIt=True, saveIt=False, cleanup=False)

Estimated memory usage: 9 MB