Use of two-line element data for thermosphere neutral density model calibration

Abstract Traditional empirical thermospheric density models are widely used in orbit determination and prediction of low-Earth satellites. Unfortunately, these models often exhibit large density errors of up to around 30% RMS. Density errors translate into orbit errors, adversely affecting applications such as re-entry operations, manoeuvre planning, collision avoidance and precise orbit determination for geodetic missions. The extensive database of two-line element (TLE) orbit data contains a wealth of information on satellite drag, at a sufficiently high spatial and temporal resolution to allow a calibration of existing neutral density models with a latency of one to two days. In our calibration software, new TLE data for selected objects is converted to satellite drag data on a daily basis. The resulting drag data is then used in a daily adjustment of density model calibration parameters, which modify the output of an existing empirical density model with the aim of increasing its accuracy. Two different calibration schemes have been tested using TLE data for about 50 objects during the year 2000. The schemes involve either height-dependent scale factors to the density or corrections to CIRA-72 model temperatures, which affect the density output based on a physical model. Both schemes have been applied with different spherical harmonic expansions of the parameters in latitude and local solar time. Five TLE objects, varying in perigee altitude between 280 and 530 km, were deliberately not used during calibration, in order to provide independent validation. Even with a single daily parameter, the RMS density model error along their tracks can already be reduced from the 30% to the 15% level. Adding additional parameters results in RMS errors lower than 12%.

[1]  J. Lean,et al.  Thermospheric density 2002-2004: TIMED/GUVI dayside limb observations and satellite drag , 2006 .

[2]  D. Drob,et al.  Nrlmsise-00 Empirical Model of the Atmosphere: Statistical Comparisons and Scientific Issues , 2002 .

[3]  E. Doornbos Thermosphere Density Model Calibration , 2007 .

[4]  J. M. Picone,et al.  Thermospheric densities derived from spacecraft orbits: Accurate processing of two‐line element sets , 2005 .

[5]  R. Nerem,et al.  Thermosphere density response to the 20-21 November 2003 solar and geomagnetic storm from CHAMP and GRACE accelerometer data , 2006 .

[6]  I. M. Levitt Advances in the astronautical sciences: Vol. 6, edited by Horace Jacobs and Eric Burgess. 898 pages, diagrams, illustrations, 612 × 978 in. New York, The Macmillan Co., 1961. Price, $25.00 , 1961 .

[7]  Felix R. Hoots,et al.  Models for Propagation of NORAD Element Sets , 1980 .

[8]  A. Hedin MSIS‐86 Thermospheric Model , 1987 .

[9]  Stephen Casali,et al.  Dynamic Calibration Atmosphere (DCA) for the High Accuracy Satellite Drag Model (HASDM) , 2002 .

[10]  R. Biancale,et al.  Improvement of the empirical thermospheric model DTM: DTM94 – a comparative review of various temporal variations and prospects in space geodesy applications , 1998 .

[11]  Gérard Thuillier,et al.  The DTM-2000 empirical thermosphere model with new data assimilation and constraints at lower boundary: accuracy and properties , 2003 .

[12]  Jeffrey M. Forbes,et al.  Global thermospheric neutral density and wind response to the severe 2003 geomagnetic storms from CHAMP accelerometer data , 2005 .

[13]  W. Tobiska,et al.  A New Empirical Thermospheric Density Model JB2006 Using New Solar Indices , 2006 .

[14]  J. Lean,et al.  Thermospheric densities derived from spacecraft orbits: Application to the Starshine satellites , 2006 .

[15]  S. Bruinsma,et al.  The Mg II index for upper atmosphere modelling , 2001 .

[16]  A. Hedin Extension of the MSIS Thermosphere Model into the middle and lower atmosphere , 1991 .

[17]  P. R. Bevington,et al.  Data Reduction and Error Analysis for the Physical Sciences , 1969 .

[18]  P. Visser,et al.  Atmospheric density calibration using satellite drag observations , 2005 .

[19]  Eelco Doornbos,et al.  Modelling of space weather effects on satellite drag , 2004 .

[20]  B. Bowman True Satellite Ballistic Coefficient Determination for HASDM , 2002 .

[21]  J. Lean,et al.  Global change in the thermosphere: Compelling evidence of a secular decrease in density , 2004 .

[22]  M. Storz,et al.  Time Series Analysis of HASDM Thermospheric Temperature and Density Corrections , 2002 .

[23]  Bruce R. Bowman,et al.  High Accuracy Satellite Drag Model (HASDM) , 2002 .

[24]  Hermann Lühr,et al.  Global distribution of the thermospheric total mass density derived from CHAMP , 2004 .

[25]  D. King-hele,et al.  Satellite orbits in an atmosphere : theory and applications , 1987 .