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NEAR Radio Science (RS) Data Archive (PDS)


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1996-02-20 to 2001-02-12


This data set contains raw and derived data from the NEAR Radio Science experiment for the entire mission: Mathilde flyby, Eros flyby, Eros orbit. In addition, gravity model results are included with landmarks identification as well as a separate shape and gravity model from the NEAR laser ranger. The flyby and orbit data sets contain: ODF - Orbit Data Files containing closed-loop (two-way) Doppler and sequential range measurements; EOP - Earth-Orientation Parameter files; ION - Ionosphere calibration files; TRO - Troposphere calibration files; and text files describing physical model inputs and estimated solution parameters. Ancillary files are needed for proper analysis and interpretation of the radio data (file type ODF). These are organized in parallel directories and stored approximately chronologically.

The gravity data set includes a 15x15 gravity model for Eros derived from radio and landmark tracking of the NEAR spacecraft, several images/maps, and a file of surface landmarks. The gravity model is defined by a set of spherical harmonic coefficients: GM, Cmn, and Smn. The image files are digital maps of Bouguer anomaly and radial gravity acceleration where the gravity field has been evaluated to degree and order less than the full 15x15 range in the model. The truncation reduces noise in the maps resulting from uncertainty in the higher degree and order coefficients. The landmark file contains rotation information for Eros and X, Y, and Z coordinates for the centers of craters identified on its surface. The shape and gravity file contains a 34 x 34 shape model for the asteroid Eros derived from NEAR Laser Rangefinder observations and a 16 x 16 gravity model derived from the shape model.

The data are contained on CD volume NREROS_2001. The PDS ID for each data set is given below:

NEAR-A-RSS-1/5-EROS/FLYBY-V1.0 ; Eros Flyby ; 1998-12-23 - 1998-12-23

NEAR-A-RSS-1/5-EROS/ORBIT-V1.0 ; Eros Orbit ; 2000-01-11 - 2001-02-12

NEAR-A-RSS-1/5-MATHILDE-V1.0 ; Mathilde Flyby ; 1997-06-25 - 1997-06-27

NEAR-A-RSS-5-EROS/GRAVITY-V1.0 ; 2000-02-14 - 2001-02-12

NEAR-A-NLR-5-EROS/SHAPE/GRAVITY-V1.0 ; 2000-04-30 - 2000-08-27

This volume has been formatted according to the ISO-9660 level 2 Interchange Standard. This volume does not contain any Extended Attribute Records (XAR). All document files and most labels contain an 80-byte fixed length record, with a carriage return (ASCII 13) and line feed (ASCII 10) as the 79th and 80th byte respectively.

Alternate Names

  • PDS NEAR Radio Sci. Data Archive


  • Planetary Science: Small Bodies
  • Planetary Science: Geology and Geophysics


  • 96-008A-05A

Additional Information



Questions and comments about this data collection can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Edwin J. Grayzeck, Jr.General ContactUniversity of
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