– The full JB2008 includes iterative temperature solutions. For Monte Carlo simulations (thousands of orbits), precompute lookup tables or use a polynomial surrogate model.
% Compare with MSISE-00 (built-in) msise_dens = atmosnrlmsise00(alt, lat, lon, doy, ut_sec, f10, f10b, ap); fprintf('JB2008 Density: %.2e kg/m³\n', dens); fprintf('MSISE-00 Density: %.2e kg/m³\n', msise_dens); fprintf('Ratio (JB/MSIS): %.2f\n', dens/msise_dens); jb2008 matlab
– Real-time F10.7 and Dst values lag by 1-2 days. For historical analysis, download from NASA OMNIWeb or Kyoto Dst . – The full JB2008 includes iterative temperature solutions
% Date: March 23, 2024 (geomagnetic storm day) doy = 83; ut_sec = 14*3600; % 14:00 UTC lat = 35; lon = -120; alt = 450e3; % Over California % Solar & geomagnetic indices (real values from SWPC) f10 = 158.2; % Daily solar flux f10b = 145.3; % 81-day mean ap = 48; % Active geomagnetic dst = -78; % Moderate storm For historical analysis, download from NASA OMNIWeb or
altitudes = 150:10:800; % km dens_jb = zeros(size(altitudes)); dens_msis = zeros(size(altitudes)); for i = 1:length(altitudes) dens_jb(i) = jb2008(altitudes(i), 0, 0, 80, 43200, 180, 170, 15, -20); dens_msis(i) = atmosnrlmsise00(altitudes(i)*1000, 0, 0, 80, 43200, 180, 170, 15); end
% Compute density [dens, T_exo] = jb2008(alt/1000, lat, lon, doy, ut_sec, f10, f10b, ap, dst);