CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 68 FILE_RECORDS = 18360 ^TABLE = "QHGA_C_2.TAB" DATA_SET_ID = "CLEM1-L-RSS-1-BSR-V1.0" PRODUCT_ID = "QHGA_C_2.TAB" SPACECRAFT_NAME = CLEMENTINE_1 INSTRUMENT_ID = RSS TARGET_NAME = MOON PRODUCT_CREATION_TIME = 1995-04-05T23:20:00.000 MISSION_PHASE_NAME = {"PRE-LAUNCH","LAUNCH", "LOW EARTH ORBIT","EARTH PHASING LOOP A","LUNAR ORBIT INSERTION", "LUNAR MAPPING","LUNAR DEPARTURE","EARTH PHASING LOOP B"} START_TIME = 1994-01-01T00:00:00.000 STOP_TIME = 1994-05-31T23:59:59.999 OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 18360 COLUMNS = 6 ROW_BYTES = 68 DESCRIPTION = "This table provides antenna pattern data in circular polarizations for the Clementine qualification model high-gain antenna (HGA). These data were derived from measurements made in orthogonal linear polarizations at 2 degree increments in cone angle from boresight (THETA=180) to 100 degrees off boresight (THETA=80). The qualification model HGA was built identically to the flight antenna and is believed to have the same boresight gain to within 0.1 dB. No measurements of comparable detail are available for the flight antenna. A second set of measurements at one-quarter degree increments in cone angle from boresight to 45 degrees off boresight is available in table QHGA_C_Q.TAB. The original, linear polarization, measurements are available in table QHGA_L_Q.TAB. Measurements were carried out on an antenna range at a distance of about 100 feet (30 meters) from the antenna; this is about twice what is usually taken to be the beginning of the 'far field' region for an antenna of this size. The measured values were not adjusted to an infinitely far field. The coordinate system for these measurements is defined as follows. The spacecraft positive x-axis is in the direction of the spacecraft main thruster. The HGA boresight is in the negative x-axis direction. The sensor panel faces in the direction of the positive z-axis. The positive y-axis makes a right-handed rectangular frame and points in the direction of the solar panel rotation axis (Y = Z x X; all unit vectors). Alignment of the HGA boresight was found to be within 0.1 degrees of the negative x-axis using laser instrumentation. The antenna pattern was measured by placing a probe at a point R. The vector to R from the center of the HGA made an angle THETA with respect to the positive X-axis. The projection of R onto the y-z plane made an angle PHI with respect to the negative z-axis; PHI was measured positive from the negative z-axis toward the negative y-axis. 'Vertical' is defined by the vector product of the vector to R and the positive x-axis (V = R x X/|R x X|). 'Horizontal' is defined by the vector product between the 'vertical' vector and the vector to R (H = V x R/|V x R|). Quantities in the table include cone and clock angles, axial ratio, tilt angle, and normalized right- and left-circularly polarized power. All values are stored in fixed-length 10-digit fields in ASCII_REAL format. Fields in the table are separated by commas; each line in the table is delimited by an ASCII blank and an ASCII carriage-return line-feed pair. These data were provided by Fred Domer of the Clementine Project." OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = "THETA" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 10 FORMAT = "F10.6" UNIT = DEGREE DESCRIPTION = "The angle from the positive x-axis (arccos{R.X/|R|}, where R.X denotes the scalar product between R and X). Since the high-gain antenna boresight is along the negative x-axis, THETA is the supplement of the HGA cone angle. The angle from the HGA boresight is 180-THETA degrees." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = "PHI" DATA_TYPE = ASCII_REAL START_BYTE = 12 BYTES = 10 FORMAT = "F10.6" UNIT = DEGREE DESCRIPTION = "The HGA clock (azimuthal) angle to probe position R, measured positive from the spacecraft negative z-axis direction toward the spacecraft negative y-axis direction. That is, PHI= 0 deg negative z-axis PHI= 90 deg negative y-axis PHI=180 deg positive z-axis PHI=270 deg positive y-axis" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = "AXIAL RATIO" DATA_TYPE = ASCII_REAL START_BYTE = 23 BYTES = 10 FORMAT = "F10.6" UNIT = DECIBEL DESCRIPTION = "The ratio of the semi-major axis of the polarization ellipse to its semi- minor axis. Zero indicates pure circular polarization; linear polarization would have an infinite axial ratio." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "TILT ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 34 BYTES = 10 FORMAT = "F10.6" UNIT = DEGREE DESCRIPTION = "The angle between the semi-major axis of the polarization ellipse and the the horizontal direction, defined by the vector H. The angle is positive measured from H toward the vector V." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = "RIGHT HAND CIRCULAR MAGNITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 45 BYTES = 10 FORMAT = "F10.6" UNIT = "DECIBEL RELATIVE TO ISOTROPIC" DESCRIPTION = "The right-hand circularly polarized power radiated in direction (THETA,PHI) from the HGA relative to the power in the same direction had the HGA been replaced by an isotropic radiator." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = "LEFT HAND CIRCULAR MAGNITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 56 BYTES = 10 FORMAT = "F10.6" UNIT = "DECIBEL RELATIVE TO ISOTROPIC" DESCRIPTION = "The left-hand circularly polarized power radiated in direction (THETA,PHI) from the HGA relative to the power in the same direction had the HGA been replaced by an isotropic radiator." END_OBJECT = COLUMN END_OBJECT = TABLE END