MMS Fast Plasma Instrument: Difference between revisions

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=== Ion Distribution Data ===
=== Ion Distribution Data ===
To load the FPI ion data:
<div style="border: 1px solid LightGray; background-color:#F9F9F9; padding: 0px 10px; margin-left: 5px; margin-right: 5px;">
MMS> mms_load_fpi, probe=1, trange=['2015-10-16/13:02:30', '2015-10-16/13:07:30'], data_rate='brst', datatype='dis-dist'
</div>
To generate the pitch angle distributions (PADs), we also need spacecraft position and magnetic field data covering the time range:
<div style="border: 1px solid LightGray; background-color:#F9F9F9; padding: 0px 10px; margin-left: 5px; margin-right: 5px;">
MMS> mms_load_state, probes=1, trange=['2015-10-16/13:01:30', '2015-10-16/13:08:30']
MMS> mms_load_fgm, probe=1, trange=['2015-10-16/13:01:30', '2015-10-16/13:08:30']
</div>
Generate and plot the ion energy spectra and PAD:
Generate and plot the ion energy spectra and PAD:


<div style="border: 1px solid LightGray; background-color:#F9F9F9; padding: 0px 10px; margin-left: 5px; margin-right: 5px;">
<div style="border: 1px solid LightGray; background-color:#F9F9F9; padding: 0px 10px; margin-left: 5px; margin-right: 5px;">
MMS> mms_part_products, 'mms1_dis_dist_brst', trange=['2015-10-16/13:02:30', '2015-10-16/13:07:30'], mag_name='mms1_fgm_b_dmpa_srvy_l2_bvec', pos_name='mms1_defeph_pos', outputs=['energy','pa']
MMS> mms_part_getspec, instrument='fpi', probe='1', species='i', data_rate='brst', level='l2', outputs=['energy', 'pa'], trange=['2015-10-16/13:02:30', '2015-10-16/13:07:30']


MMS> tdegap, '*_dis_dist_brst_*', /overwrite ; be sure not to interpolate through data gaps
MMS> tdegap, '*_dis_dist_brst_*', /overwrite ; be sure not to interpolate through data gaps
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Mms_part_products_ion_spec.png|MMS1 FPI ion spectra and PAD on October 16, 2015
Mms_part_products_ion_spec.png|MMS1 FPI ion spectra and PAD on October 16, 2015
</gallery>
</gallery>


= FPI 2D Slices =
= FPI 2D Slices =

Revision as of 04:14, 17 May 2017

FPI summary plot in SPEDAS

SPEDAS provides command line and GUI access to the MMS FPI data.


Prior to using these data, please read the FPI Release Notes:

https://lasp.colorado.edu/mms/sdc/public/datasets/fpi/ (FPI Release Notes)


FPI Moments

For more complete examples, see the FPI crib sheets located in the /mms/examples/ folder.

Examples

Electron Moments Data

To load and plot the MMS1 FPI electron moments data on March 7, 2016:

MMS> mms_load_fpi, datatype='des-moms', trange=['2016-03-07', '2016-03-08'], probe=1

MMS> tplot, 'mms1_des_numberdensity_fast'

MMS> tplot, ['mms1_des_energyspectr_omni_fast', 'mms1_des_pitchangdist_avg']


Ion Moments Data

To load and plot the ion density, along with the omni-directional spectra on March 7, 2016:

MMS> mms_load_fpi, datatype='dis-moms', trange=['2016-03-07', '2016-03-08'], probe=1

MMS> tplot, ['mms1_dis_numberdensity_fast', 'mms1_dis_energyspectr_omni_fast']


FPI Distributions

SPEDAS can also be used to load and generate spectra from the FPI distribution functions.

Examples

Electron Distribution Data

Generate and plot the electron energy spectra and PAD:

MMS> mms_part_getspec, instrument='fpi', probe='1', species='e', data_rate='brst', level='l2', outputs=['phi', 'theta', 'energy', 'pa', 'gyro'], trange=['2015-10-16/13:02:30', '2015-10-16/13:07:30']

MMS> tdegap, '*_des_dist_brst_*', /overwrite ; be sure not to interpolate through data gaps

MMS> tplot, ['mms1_des_dist_brst_energy', 'mms1_des_dist_brst_pa']


Ion Distribution Data

Generate and plot the ion energy spectra and PAD:

MMS> mms_part_getspec, instrument='fpi', probe='1', species='i', data_rate='brst', level='l2', outputs=['energy', 'pa'], trange=['2015-10-16/13:02:30', '2015-10-16/13:07:30']

MMS> tdegap, '*_dis_dist_brst_*', /overwrite ; be sure not to interpolate through data gaps

MMS> tplot, ['mms1_dis_dist_brst_energy', 'mms1_dis_dist_brst_pa']


FPI 2D Slices

Examples

Basic 2D Slices

Load the FPI ion distribution data:

MMS> mms_load_fpi, data_rate='brst', datatype='dis-dist', probe=1, trange=['2015-10-16/13:06', '2015-10-16/13:07']


Reformat the data for ploting using spd_slice2d:

MMS> dist = mms_get_dist('mms1_dis_dist_brst', trange=['2015-10-16/13:06', '2015-10-16/13:07'])

MMS> slice = spd_slice2d(dist, time='2015-10-16/13:06') ;3D interpolation


Now plot the slice:

MMS> spd_slice2d_plot, slice


Visualizing 3D Distribution Functions

SPEDAS can also be used for visualizing MMS 3D distribution functions from FPI using the ISEE3D tool, developed by the Institute for Space-Earth Environmental Research (ISEE), Nagoya University, Japan.


Load data into tplot

MMS> mms_load_fpi, probe=1, trange=['2015-10-20/05:56:30', '2015-10-20/05:56:34'], data_rate='brst', datatype='dis-dist'


Load the data into standard structures

MMS> dist = mms_get_fpi_dist('mms1_dis_dist_brst' , trange=['2015-10-20/05:56:30', '2015-10-20/05:56:34'])

MMS> data = spd_dist_to_hash(dist) ;convert structures to isee_3d data model


Load the magnetic field (cyan vector) and velocity (yellow vector) support data

MMS> mms_load_fgm, probe=1, trange=['2015-10-20/05:55:30', '2015-10-20/05:57:34'], level='l2'

MMS> mms_load_fpi, data_rate='brst', datatype='dis-moms', probe=1, trange=['2015-10-20/05:56:30', '2015-10-20/05:56:34']

MMS> join_vec, 'mms1_dis_bulk' + ['x','y','z'] +'_dbcs_brst', 'mms1_dis_bulk' ;combine separate velocity components


Once the GUI is opened, select PSD from Units menu

MMS> isee_3d, data=data, trange=['2015-10-20/05:56:30', '2015-10-20/05:56:34'], bfield='mms1_fgm_b_gse_srvy_l2_bvec', velocity='mms1_dis_bulk'