CHAMP MAG

Abstract: Accesing CHAMP magnetic products, provided by GFZ

Rother, Martin; Michaelis, Ingo (2019): CH-ME-3-MAG - CHAMP 1 Hz Combined Magnetic Field Time Series (Level 3). GFZ Data Services. https://doi.org/10.5880/GFZ.2.3.2019.004

%load_ext watermark
%watermark -i -v -p viresclient,pandas,xarray,matplotlib

Python implementation: CPython
Python version       : 3.11.6
IPython version      : 8.18.0

viresclient: 0.15.2
pandas     : 2.1.3
xarray     : 2023.12.0
matplotlib : 3.8.2

from viresclient import SwarmRequest
import datetime as dt
import numpy as np
import matplotlib.pyplot as plt

request = SwarmRequest()

request.available_collections("MAG_CHAMP", details=False)

{'MAG_CHAMP': ['CH_ME_MAG_LR_3']}

request.available_measurements("CH_ME_MAG_LR_3")

['F',
 'B_VFM',
 'B_NEC',
 'Flags_Position',
 'Flags_B',
 'Flags_q',
 'Mode_q',
 'q_ICRF_CRF']

request.set_collection("CH_ME_MAG_LR_3")
# request.set_collection("SW_OPER_MAGA_LR_1B")
request.set_products(
    measurements=[
        # 'F',
        "B_NEC",
        # 'B_FGM',
        # 'q_ASC_CRF',
        # 'ASC_MODE',
        # 'ASC_STAT',
        # 'GEO_STAT',
        # 'FGM_FLAGS'
    ],
    models=["CHAOS"],
    sampling_step="PT10S",
    auxiliaries=["OrbitNumber"],
    # auxiliaries=["OrbitNumber", "OrbitDirection", "QDOrbitDirection", "MLT"]
)
data = request.get_between(
    start_time="2002-01-01T00:00:00Z",
    end_time="2002-02-01T00:01:00Z",
    asynchronous=True,
)
ds = data.as_xarray()
ds["B_NEC_res_Model"] = ds["B_NEC"] - ds["B_NEC_CHAOS"]
ds

<xarray.Dataset>
Dimensions:          (Timestamp: 267846, NEC: 3)
Coordinates:
  * Timestamp        (Timestamp) datetime64[ns] 2002-01-01T00:00:00.140000 .....
  * NEC              (NEC) <U1 'N' 'E' 'C'
Data variables:
    Spacecraft       (Timestamp) object '-' '-' '-' '-' '-' ... '-' '-' '-' '-'
    Latitude         (Timestamp) float64 84.99 85.52 86.02 ... -35.13 -34.49
    OrbitNumber      (Timestamp) int32 8247 8247 8247 8247 ... 8727 8727 8727
    B_NEC            (Timestamp, NEC) float64 -304.9 -2.104 ... -4.052e+04
    Radius           (Timestamp) float64 6.768e+06 6.768e+06 ... 6.783e+06
    Longitude        (Timestamp) float64 -118.3 -113.8 -108.1 ... 164.1 164.1
    B_NEC_CHAOS      (Timestamp, NEC) float64 -275.3 53.81 ... -4.054e+04
    B_NEC_res_Model  (Timestamp, NEC) float64 -29.6 -55.92 41.35 ... 21.0 17.64
Attributes:
    Sources:         ['CHAMP ME MAG ORBITCOUNT', 'CHAOS-8.1_static.shc', 'CH_...
    MagneticModels:  ["CHAOS = 'CHAOS-Core'(max_degree=20,min_degree=1) + 'CH...
    AppliedFilters:  []

xarray.Dataset

• Dimensions:
  • Timestamp: 267846
  • NEC: 3
• Coordinates: (2)
  • Timestamp
    (Timestamp)
    datetime64[ns]
    2002-01-01T00:00:00.140000 ... 2...

    description :

    Timestamp

    array(['2002-01-01T00:00:00.140000000', '2002-01-01T00:00:10.140000000',
           '2002-01-01T00:00:20.140000000', ..., '2002-02-01T00:00:30.140000000',
           '2002-02-01T00:00:40.140000000', '2002-02-01T00:00:50.140000000'],
          dtype='datetime64[ns]')

  • NEC
    (NEC)
    <U1
    'N' 'E' 'C'

    units :

    description :

    NEC frame - North, East, Centre (down)

    array(['N', 'E', 'C'], dtype='<U1')

• Data variables: (8)
  • Spacecraft
    (Timestamp)
    object
    '-' '-' '-' '-' ... '-' '-' '-' '-'

    units :

    -

    description :

    Spacecraft identifier (values: 'A', 'B', 'C' or '-' if not available).

    array(['-', '-', '-', ..., '-', '-', '-'], dtype=object)

  • Latitude
    (Timestamp)
    float64
    84.99 85.52 86.02 ... -35.13 -34.49

    units :

    deg

    description :

    [deg] Position in ITRF - Latitude

    array([ 84.99274044,  85.5226695 ,  86.01687483, ..., -35.77944422,
           -35.13271037, -34.48597511])

  • OrbitNumber
    (Timestamp)
    int32
    8247 8247 8247 ... 8727 8727 8727

    units :

    -

    description :

    Orbit number (set to -1 if not available)

    array([8247, 8247, 8247, ..., 8727, 8727, 8727], dtype=int32)

  • B_NEC
    (Timestamp, NEC)
    float64
    -304.9 -2.104 ... -4.052e+04

    units :

    nT

    description :

    [nT] B-Vector in NEC system

    array([[-3.04858612e+02, -2.10364294e+00,  4.79531484e+04],
           [-4.59912689e+02, -2.44267670e+02,  4.78920078e+04],
           [-5.62042786e+02, -5.38003906e+02,  4.78257383e+04],
           ...,
           [ 1.91717637e+04,  5.76910693e+03, -4.14494023e+04],
           [ 1.94929980e+04,  5.75511035e+03, -4.09879453e+04],
           [ 1.98117227e+04,  5.73929199e+03, -4.05181445e+04]])

  • Radius
    (Timestamp)
    float64
    6.768e+06 6.768e+06 ... 6.783e+06

    units :

    m

    description :

    [m] Position in ITRF - Radius

    array([6768304.54654078, 6768488.52763162, 6768676.36275165, ...,
           6782484.20286562, 6782621.22999938, 6782758.92788293])

  • Longitude
    (Timestamp)
    float64
    -118.3 -113.8 ... 164.1 164.1

    units :

    deg

    description :

    [deg] Position in ITRF - Longitude

    array([-118.33090611, -113.80851405, -108.11206165, ...,  164.08676363,
            164.09160425,  164.09570829])

  • B_NEC_CHAOS
    (Timestamp, NEC)
    float64
    -275.3 53.81 ... -4.054e+04

    units :

    nT

    description :

    Magnetic field vector, NEC frame, calculated by the CHAOS spherical harmonic model

    array([[  -275.25970568,     53.81418309,  47911.79678646],
           [  -434.84241748,   -195.40564853,  47852.68784048],
           [  -544.80422228,   -476.88885894,  47788.55249535],
           ...,
           [ 19192.27215035,   5747.87714428, -41465.09685256],
           [ 19512.23453269,   5733.37298784, -41004.69391271],
           [ 19829.86545988,   5718.29550829, -40535.78829497]])

  • B_NEC_res_Model
    (Timestamp, NEC)
    float64
    -29.6 -55.92 41.35 ... 21.0 17.64

    array([[-29.59890638, -55.91782603,  41.35165104],
           [-25.07027173, -48.86202115,  39.31997202],
           [-17.23856336, -61.11504731,  37.1857859 ],
           ...,
           [-20.50847848,  21.22978932,  15.69450881],
           [-19.23648581,  21.73736372,  16.74860021],
           [-18.14280363,  20.9964839 ,  17.64376372]])

• Indexes: (2)
  • Timestamp
    PandasIndex

    PandasIndex(DatetimeIndex(['2002-01-01 00:00:00.140000', '2002-01-01 00:00:10.140000',
                   '2002-01-01 00:00:20.140000', '2002-01-01 00:00:30.140000',
                   '2002-01-01 00:00:40.140000', '2002-01-01 00:00:50.140000',
                   '2002-01-01 00:01:00.140000', '2002-01-01 00:01:10.140000',
                   '2002-01-01 00:01:20.140000', '2002-01-01 00:01:30.140000',
                   ...
                   '2002-01-31 23:59:20.140000', '2002-01-31 23:59:30.140000',
                   '2002-01-31 23:59:40.140000', '2002-01-31 23:59:50.140000',
                   '2002-02-01 00:00:00.140000', '2002-02-01 00:00:10.140000',
                   '2002-02-01 00:00:20.140000', '2002-02-01 00:00:30.140000',
                   '2002-02-01 00:00:40.140000', '2002-02-01 00:00:50.140000'],
                  dtype='datetime64[ns]', name='Timestamp', length=267846, freq=None))

  • NEC
    PandasIndex

    PandasIndex(Index(['N', 'E', 'C'], dtype='object', name='NEC'))

• Attributes: (3)

  Sources :

  ['CHAMP ME MAG ORBITCOUNT', 'CHAOS-8.1_static.shc', 'CH_ME_MAG_LR_3_20011231_0102', 'CH_ME_MAG_LR_3_20020101_0102', 'CH_ME_MAG_LR_3_20020102_0102', 'CH_ME_MAG_LR_3_20020103_0102', 'CH_ME_MAG_LR_3_20020104_0102', 'CH_ME_MAG_LR_3_20020105_0102', 'CH_ME_MAG_LR_3_20020106_0102', 'CH_ME_MAG_LR_3_20020107_0102', 'CH_ME_MAG_LR_3_20020108_0102', 'CH_ME_MAG_LR_3_20020109_0102', 'CH_ME_MAG_LR_3_20020110_0102', 'CH_ME_MAG_LR_3_20020111_0102', 'CH_ME_MAG_LR_3_20020112_0102', 'CH_ME_MAG_LR_3_20020113_0102', 'CH_ME_MAG_LR_3_20020114_0102', 'CH_ME_MAG_LR_3_20020115_0102', 'CH_ME_MAG_LR_3_20020116_0102', 'CH_ME_MAG_LR_3_20020117_0102', 'CH_ME_MAG_LR_3_20020118_0102', 'CH_ME_MAG_LR_3_20020119_0102', 'CH_ME_MAG_LR_3_20020120_0102', 'CH_ME_MAG_LR_3_20020121_0102', 'CH_ME_MAG_LR_3_20020122_0102', 'CH_ME_MAG_LR_3_20020123_0102', 'CH_ME_MAG_LR_3_20020124_0102', 'CH_ME_MAG_LR_3_20020125_0102', 'CH_ME_MAG_LR_3_20020126_0102', 'CH_ME_MAG_LR_3_20020127_0102', 'CH_ME_MAG_LR_3_20020128_0102', 'CH_ME_MAG_LR_3_20020129_0102', 'CH_ME_MAG_LR_3_20020130_0102', 'CH_ME_MAG_LR_3_20020131_0102', 'CH_ME_MAG_LR_3_20020201_0102', 'SW_OPER_MCO_SHA_2X_19970101T000000_20260807T235959_0806', 'SW_OPER_MMA_CHAOS__20020101T000000_20021231T233000_0806']

  MagneticModels :

  ["CHAOS = 'CHAOS-Core'(max_degree=20,min_degree=1) + 'CHAOS-Static'(max_degree=185,min_degree=21) + 'CHAOS-MMA-Primary'(max_degree=2,min_degree=1) + 'CHAOS-MMA-Secondary'(max_degree=2,min_degree=1)"]

  AppliedFilters :

  []

ds["B_NEC_res_Model"].plot.line(x="Timestamp")

[<matplotlib.lines.Line2D at 0x7faa24350510>,
 <matplotlib.lines.Line2D at 0x7faa18a8a490>,
 <matplotlib.lines.Line2D at 0x7fa9fae52f90>]