NAME: thm_scpot2dens_opt_n PURPOSE: Convert the spacecraft potential to the electron density CATEGORY: EFI, ESA CALLING SEQUENCE: thm_scpot2dens_opt_n,sc=sc,datatype_esa=datatype_esa,trange=trange EXAMPLE: thm_scpot2dens_opt_n,sc='d',datatype_esa='peer' ;scpot and vthermal from peer PRE-REQUIREMENTS: Timespan for the calculation like timespan,'2009-01-01/00:00:00',1,/day KEYWORD PARAMETERS: probe spacecraft name: 'a', 'b', 'c', 'd' or 'e'. Default is 'a'. datatype_esa ESA datatype: 'peef', 'peer', 'peem' or 'peeb'. Default is 'peer'. trange The time range to input, if not set, then the timespan value is used. OUTPUTS: 'th?_*_density' Electron density in cm-3 RESTRICTIONS: The calculated electron density may include uncertainties. Uncertainties are larger where the thermal velocity of electrons is not accurately estimated: in the plasmasphere, plasmatrough and lobe. Error data in the electron thermal speed or spacecraft potential give unreliable denisities. MODIFICATION HISTORY: Written by: Toshi Nishimura@UCLA/NAGOYA, 05/02/2009 (toshi at atmos.ucla.edu) Modification 05/26/2009 Add keywords 'datatype_esa'. Modification 07/13/2009 Update the scpot-density relation mainly for the plasmasphere. Modfication 10/08/2009 Added trange keyword, jmm, jimm@ssl.berkeley.edu Collaborators: Vassilis Angelopoulos, John Bonnell and Wen Li It is recommended to contact people listed above before presentations or publications using the data created by this code.