urn:nasa:pds:clementine1_bistatic:sort:srtnpwr_reconstructed 1.0 1.21.0.0 Product_Observational 2024-05-13 1.0 Original version. 1994-04-09T18:36:45Z 1999-04-09T18:52:44Z Deep Space Program Science Experiment Mission urn:nasa:pds:context:investigation:mission.deep_space_program_science_experiment data_to_investigation Clementine 1 Clementine 1 Host urn:nasa:pds:context:instrument_host:spacecraft.clem1 is_instrument_host Radio Science Subsystem Instrument urn:nasa:pds:context:instrument:clem1.rss is_instrument Moon Satellite urn:nasa:pds:context:target:satellite.earth.moon data_to_target urn:nasa:pds:clementine1_bistatic:document:srtnpwr data_to_associate Original, incomplete version srtnpwr_reconstructed.tab 2024-03-28T17:34:26Z NUMBER DISTRIBUTION 0 101 This version has been reconstructed. During migration from PDS3, it was discovered that the second field (NUMBER OF VALID POINTS) of the original file, SRTNPWR.TAB, contains only 63 of the 72 intended columns. The version named SRTNPWR_RECONSTRUCTED.TAB is a plausible reconstruction of the intended table. According to its PDS3 label, each row in SRTNPWR.TAB corresponds to a specific beta and each column in the NUMBER OF VALID POINTS field corresponds to 1 of 72 targets. Each value in this field is then the count of valid values for a particular beta-target combination in SRTPWRR.TAB and SRTPWRL.TAB (hereinafter, the "source files"). Moreover, within each row of those source files, in the RCP ECHO POWERS field, all valid values come first, followed by a 0.00 for each remaining value. (For ease of reference, each 0.00 in an uninterrupted sequence of 0.00's at the end of the RCP ECHO POWERS field in a source file will be called a "trailing 0.00" hereinafter.) This information leaves two questions for reconstruction: 1) If one source file has a nonzero value for a given beta-target combination but the other source file has a trailing 0.00 for that same beta-target combination (that is, on equivalent rows, trailing 0.00's start later in one source file than in the other), should that half-nonzero, half-zero beta-target combination be tallied in NUMBER OF VALID POINTS? 2) Should a trailing 0.00 common to both source files always be excluded from the count in NUMBER OF VALID POINTS? In other words, is it impossible for the first one or more common trailing 0.00's to represent valid values, whose "trailing" location is merely coincidental? To create SRTNPWR_RECONSTRUCTED.TAB, we assumed that the answer is Yes to both questions. The first 63 columns (6363 values) of NUMBER OF VALID POINTS in that reconstruction exactly match all 63 columns of the same field in SRTNPWR.TAB. These values include the only six locations where Question 1 applies out of all values in the reconstruction, suggesting that the answer to Question 1 is indeed Yes, as also suggested by an example in the PDS3 label to SRTNPWR.TAB. Within the 63 columns of NUMBER OF VALID POINTS common to both SRTNPWR.TAB and its reconstruction, there is no example where the answer to Question 2 is No. However, it is at least conceivable that the answer to Question 2 could be No for one or more values in the nine columns unique to SRTNPWR_RECONSTRUCTED.TAB. To represent this uncertainty, we refer to SRTNPWR_RECONSTRUCTED.TAB as a "plausible" reconstruction. The remaining text in this description comes from the PDS3 label for the original (incomplete) version, SRTNPWR.TAB. This table gives the number of valid points at each (BETA,TARGET) location in SRTPWRL.TAB and SRTPWRR.TAB. Clementine bistatic radar echoes between 18:36:00 and 18:52:00 on 1994-04-09 were stored as 1464 1024-point power spectra. Every frequency bin in every spectrum can be associated with a contour of constant Doppler offset from the South Pole. Each contour comes closest to one of 72 'target' points defined on the surface. Target points are spaced by one second in time and satisfy the condition that the bistatic angle (BETA) passes through zero at some time during the experiment. The target points are given in BETAZER0.TAB and BETAZER1.TAB in the GEOMETRY directory of this archive. RCP echoes were sorted into array PWRR(BETA,TARGET,ELEMENT); LCP echoes were sorted into PWRL(BETA,TARGET,ELEMENT). TARGET depends on which target point fell within the 1.53 Hz Doppler bin. If none, the measurement was not included in the array. If yes, the value for TARGET was between 1 and 72, where the targets are in time order and 72 is the number of the final target point on the surface -- 6.5 seconds after South Pole closest approach. The bistatic angle was computed for the target selected at the time of the measurement. Bins of width 0.1 degree were defined centered on BETA = -5.0, -4.9, -4.8, ..., 4.8, 4.9, 5.0 Negative values of BETA indicate observation times before BETA = 0. Each successfully binned measurement at (BETA,TARGET) was assigned an ELEMENT number, starting from 1. The maximum number of points assigned at any (BETA,TARGET) was 42. Hence, the dimensions of PWRR and PWRL are 101x72x42. Unused ELEMENT positions are padded with zeros. This table tells how many of the points at each (BETA,TARGET) are valid. The number applies to both PWRR and PWRL. The table consists of two columns. The first column is an index for BETA. The second column (containing 72 items) gives the number of valid measurements at each of the targets. Columns and items are delimited by commas. Each row in the table is delimited by an ASCII carriage-return line-feed pair. Carriage-Return Line-Feed 1 1 293 BETA INDEX 1 1 ASCII_Integer 3 The BETA index for three-dimensional arrays of sorted scattered power. The index increases from 1 to 101 as the bistatic angle BETA increases from -5.0 to +5.0 in steps of 0.1 degree. 1 72 2 0 The number of valid points at location (BETA,TARGET) in arrays stored in files SRTPWRL.TAB and SRTPWRR.TAB. For example, if the value at (BETA_INDEX=3,ITEM=TARGET=5) in this array is 11, then the first 11 values at (3,5) in SRTPWRR.TAB are valid and the first 11 values at (3,5) in SRTPWRL.TAB are valid (the remaining 31 entries should be set to 0.00). 5 288 NUMBER OF VALID POINTS 1 1 ASCII_Integer 3 [UNUSED] 2 4 ASCII_String 1 Field added during migration from PDS3 to accommodate inter-field bytes. These bytes are not documented in the PDS3 label.