;+ ; Batch File: THM_CRIB_FIT ; ; Purpose: Demonstrate the loading, calibration, and plotting ; of THEMIS FIT (On-Board E- and B-Field SpinFit) data. ; ; Calling Sequence: ; .run thm_crib_fit, or using cut-and-paste. ; ; Arguements: ; None. ; ; Notes: ; None. ; ;Written by John Bonnell ; $LastChangedBy: pcruce $ ; $LastChangedDate: 2013-09-19 11:14:02 -0700 (Thu, 19 Sep 2013) $ ; $LastChangedRevision: 13081 $ ; $URL $ ;- print, "--- Start of crib sheet ---" ; FIT On-Board SpinFit data example. ; set a few TPLOT options. tplot_title = 'THEMIS FIT On-Board Spin Fit Examples' tplot_options, 'title', tplot_title tplot_options, 'xmargin', [ 15, 10] tplot_options, 'ymargin', [ 5, 5] ; set the timespan and load the FIT data. ;timespan, '2007-06-30', 1.0, /day timespan, '2008-05-15', 1.0, /day thm_load_fit, level=1,datatype=['efs', 'fgs'],/verbose ; set the color table. loadct2, 39 ; the FIT data, as loaded by THM_LOAD_FIT isn't very usable or viewable, ; so run THM_CAL_FIT to break out the E and B fits with useful plotting options. ; plot the calibrated FIT data. tplot, ['thc_efs', 'thc_fgs'] print, 'at each stop point type .c to continue with the crib' stop ;tlimit, ['2007-06-30/00:45:00', '2007-06-30/16:30:00'] tlimit, ['2008-05-15/10:00:00', '2008-05-15/14:00:00'] print, 'now we zoomed in' stop tplot, 'th?_fgs th?_efs' print, 'all probes plotted.' ; Note only probes Charley, Delta, Echo have ' ;print, 'booms deployed for good E-Field data.' stop thm_load_state, /get_support_data thm_cotrans, 'th?_??s', out_suffix='_gsm', out_coord='gsm' tplot, [ 'thc_efs', 'thc_fgs', $ 'thc_efs_gsm', 'thc_fgs_gsm'] print, 'we transformed both efs and fgs to gsm, adding _gsm suffix to result' stop thm_load_fit, level=1,datatype=['efs', 'fgs'], coord='gsm', suffix='_gsm' tplot, [ 'thc_efs', 'thc_fgs', $ 'thc_efs_gsm', 'thc_fgs_gsm'] print, 'you can get the same result (with better plot labels) if you load' print, 'specify the coord keyword to thm_load_fit.' stop thm_load_fgm, datatype=['fgs'],/verbose, suffix='_l2', level = 'l2' ; L2 EFI not yet available... ;thm_load_efi, datatype=['efs'],/verbose, suffix='_l2' tplot, ['thc_fgs', 'thc_fgs_dsl_l2'] print, 'now we loaded the same data from level 2. Note L2 data has a ' print, 'suffix to designate the coordinate. ' print, 'EFI is not yet available directly from L2 files.' stop ; Example showing use of eclipse spin model corrections for FIT data ; THB passed through a lunar shadow during this flyby. The eclipse ; occurs between approximately 0853 and 0930 UTC. timespan,'2010-02-13/08:00',4,/hours ; 2012-08-03: By default, the eclipse spin model corrections are not ; applied. For clarity, we'll explicitly set use_eclipse_corrections to 0 ; to get a comparison plot, showing how the lack of eclipse spin model ; corrections induces an apparent rotation in the data. thm_load_fit,probe='b',level=1,type='calibrated',suffix='_before',use_eclipse_corrections=0 ; Here we load the same data, but enable the full set of eclipse spin ; model corrections by setting use_eclipse_corrections to 2. ; ; use_eclipse_corrections=1 is not recommended except for SOC processing. ; It omits an important spin phase offset value that is important ; for data types that are despun on board: particles, moments, and ; spin fits. ; ; Note that calibrated L1 data must be requested in order to use ; the eclipse spin model corrections. The corrections are not ; yet enabled in the L1->L2 processing. thm_load_fit,probe='b',level=1,type='calibrated',suffix='_after',use_eclipse_corrections=2 ; Plot the data to compare the results before and after the eclipse ; spin model corrections have been applied. In the uncorrected ; data, the field is clearly rotating in the spin plane, due to ; the spin-up that occurs during the eclipse as the probe and ; booms cool and contract. ; ; The corrections are applied to both EFS and FGS, but the ; effect is much more visible in FGS, so I just plotted that. tplot,['thb_fgs_before','thb_fgs_after'] print, "This plot shows the effect of enabling the eclipse spin model" print, "corrections on FIT (FGS and EFS) data. The variables with " print, "suffix _before have not had the corrections applied, while" print, "the variables with suffix _after use the eclipse corrections." print, "Without the corrections, a spin phase offset and slow rotation" print, "are visible in the data during the eclipse (0853-0930 UTC), due " print, "to the spin-up that occurs as the probe and booms cool and contract." print, " " print, "--- End of crib sheet ---" end