NSSDCA ID: PSFP-00280
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System. ==================================================================== Overview: ========= Lunar Prospector magnetometer (MAG) Level 2 Data (CODMAC Level 4). Selected and filtered time series data at 5 second intervals from the Lunar Prospector (LP) polar orbital mission to the Moon (January 1998 to July 1999). These data represent approximate measurements of the lunar crustal magnetic field with external (solar wind and magnetospheric) fields removed or minimized. Latitude / longitude coverage is limited to specific regions overpassed by thespacecraft during the selected intervals. Vector magnetic field components are given in two coordinate systems: Selenographic (SG) coordinates and east, north, and radial (ENR) coordinates. ====================================================================== Parameters: ========= The measured parameters consist of the three vector components of the lunar crustal magnetic field in SG and ENR coordinates sampled at 5-second intervals. The units of the field measurements are nanoTeslas (nT). 1 nT = 0.00001 Gauss. SG coordinates is a system centered in the Moon with X directed toward 0 N, 0 E, Z directed toward the north selenographic pole, and Y directed toward 0 N, 90 E. ENR coordinates are centered at the instantaneous spacecraft location with X directed eastward, Y directed northward, and Z directed radial to the Moon. ====================================================================== Processing: ========= Data were first selected from magnetically quiet periods when the Moon was in a lobe of the Earth's magnetotail or when the Moon was in the solar wind but the spacecraft was in the lunar wake. Hand-editing was applied to eliminate intervals of obvious transient external fields. Finally, long-wavelength (> 500 km) non-lunar fields were minimized (detrended) using a suitable filter. ====================================================================== File Names and Format: ========= Each file (in ascii format) is named as yy_ddd_nnx.TAB, where yy is year number (98 or 99), ddd is day of year, nn is orbit number on the selected day, x is an optional letter (A, B, etc.) to distinguish multiple files in one day, and 'TAB' indicates an ASCII table file. Each file contains the Universal time hour of day of the measurement, the magnetic field components (BX, BY, BZ) in SG coordinates, the magnetic field components (BE, BN, BR) in ENR coordinates, the latitude, longitude, and approximate altitude (in kilometers) above the lunar surface at which the measurement was obtained. The altitude is estimated by subtracting the mean lunar radius (1738 km) from the radial distance of the spacecraft to the lunar center of figure. List of columns in the files: Column 1: Hour of day in Universal time (to 4 decimal places) Column 2: BX in nanoTeslas; X component of the magnetic field in SG Coordinates. See Data Set Description for definition of SG Coordinates. Column 3: BY in nanoTeslas; Y component of the magnetic field in SG Coordinates. Column 4: BZ in nanoTeslas; Z component of the magnetic field in SG Coordinates. Column 5: BE in nanoTeslas; East comp. of the magnetic field in ENR coordinates. See Data Set Description for definition of ENR coordinates. Column 6: BN in nanoTeslas; North comp. of the magnetic field in ENR coordinates. Column 7: BR in nanoTeslas; Radial comp. of the magnetic field in ENR coordinates. Column 8: Lunar Latitude in degrees; north is positive. Column 9: Lunar east longitude in degrees. Column 10: Approximate altitude of spacecraft in kilometers.
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Mario H. Acuna | Data Provider | ||
Dr. Lonnie L. Hood | General Contact | University of Arizona | lonnie@hindmost.lpl.arizona.edu |