;+ ; crib_tt89 ; ; Purpose: demonstrates the use of the tt89 procedure. This procedure ; is tplot based version of the Tsyganenko 89 magnetic fields model ; ; Notes: Haje Korth's IDL/Geopack DLM must be installed for this ; to work ; ; $LastChangedBy: pcruce $ ; $LastChangedDate: 2013-12-16 17:16:12 -0800 (Mon, 16 Dec 2013) $ ; $LastChangedRevision: 13685 $ ; $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/external/IDL_GEOPACK/examples/crib_tt89.pro $ ;- timespan, '2007-03-23' ;load state data thm_load_state, probe = 'b', coord = 'gsm' ;calculate model field tt89, 'thb_state_pos' ;load fgm data for comparison thm_load_fgm, probe = 'b', coord = 'gsm', level = 2 tplot_names tplot, ['thb_state_pos_bt89', 'thb_fgs_gsm'] stop ;To properly match the elements of the model field and 'thb_fgs_gsm', ;We need to either (1) sort the input vectors, so that the tvector_rotate procedure can match rotations ;or (2) interpolate the model field on to the data ;Option 1: Sorting ;get_data,'thb_fgs_gsm',data=d ;get data ;sorted = uniq(d.x,bsort(d.x)) ;sort and remove duplication ;store_data,'thb_fgs_gsm',data={x:d.x[sorted],y:d.y[sorted,*]};store again ;Option 2: interpolation ; tinterpol_mxn,'thb_state_pos_bt89','thb_fgs_gsm',newname='thb_state_pos_bt89' ;now translate magnetometer data into model aligned coordinates ;first we make the transformation matrix fac_matrix_make, 'thb_state_pos_bt89', other_dim = 'Xgse', newname = $ 'mod_mat' ;then we rotate tvector_rotate, 'mod_mat', 'thb_fgs_gsm' tplot_names ;model field, measured field, measured field in model coordinates tplot, ['thb_state_pos_bt89', 'thb_fgs_gsm', 'thb_fgs_gsm_rot'] stop ;now substract model from the fgs data ;first interpolate the values onto the same grid tinterpol_mxn,'thb_state_pos_bt89','thb_fgs_gsm',newname='mod_interp' ;now subtract dif_data,'thb_fgs_gsm','mod_interp',newname='fgs_dif' ;set it up so model and fgm data are on the same plot get_data,'mod_interp',data=d1 get_data,'thb_fgs_gsm',data=d2,dlimits=dl d = {x:d1.x,y:[[d1.y],[double(d2.y)]],v:d1.v} str_element,/add_replace,dl,'colors',[dl.colors,dl.colors] str_element,/add_replace,dl,'labels',[dl.labels,dl.labels] store_data,'mod_fgm',data=d,dlimits=dl ylim,'fgs_dif',-400,1000 ;to reset to autoscaling on the y axis type ;ylim,'fgs_dif',/default ;now plot tplot,['mod_fgm','fgs_dif'] tlimit,'2007-03-23/18:03:00','2007-03-23/17:48:05' stop ;dipole tilt example ;add one degree to dipole tilt ;Can also add time varying tilts, or replace the default dipole tilt with a user defined value tt89, 'thb_state_pos',kp=2.0,get_tilt='tilt_vals',add_tilt=1 tplot, ['thb_state_pos_bt96', 'thb_fgs_gsm','tilt_vals'] end