MRO SHARAD Reduced Data Record (RDR)
RDR – Reduced Data Record
Instrument: Shallow Radar
PDS Data Set ID: MRO-M-SHARAD-4-RDR-V1.0
For more information about SHARAD RDR products, see the SHARAD RDR SIS.
The Shallow Radar (SHARAD) Reduced Data Record (RDR) for SHARAD is a data product produced by the Italian SHARAD team that consists of received echoes that have been Doppler filtered, range compressed, and converted to complex voltages, correlated with the auxiliary information needed to locate observations in space and time and to process data further. Data users must be aware that processed echoes may contain artifacts due to off-nadir surface reflections, the so-called clutter, reaching the radar after nadir surface echoes, and thus appearing as subsurface reflections.
Each Data Product is the result of the processing of all echoes acquired continuously in time using the same operation mode, instrument status and on-board processing scheme. There is one RDR data product for every Experiment Data Record (EDR) data product acquired in subsurface sounding mode, which in fact constitutes the input for the RDR product generation. Each processed radar observation in an RDR data product is the result of range and azimuth processing of a variable number of raw echoes. The natural organization for processed echoes within a Data Product is a table, in which each line contains data from a single processed echo, and each column contains the value of a single parameter or time sample across different processed echoes.
Each Data Product consists of two files:
-
A binary file containing the scientific data of the instrument: a sequence of processed echoes, each of which is preceded by a header containing information on the instrument setting and on-board processing of the data, and followed by parameters characterizing the ground processing of the echoes, by geometric quantities generated on-ground from spacecraft navigation data, and by parameters extracted from instrument housekeeping telemetry.
-
A detached ASCII PDS label file describing the content of the data product.
SHARAD RDR files have the following file names:
R_nnnnnnn_mmm_aabb_ppp_v.DAT (with detached PDS label)
where:
nnnnnnn = transaction ID, 0000000-9999999, 7-digit number associated with the ID contained in the Instrument Raw Science Product filename from which the EDR is produced, the first five digits correspond to the number of the orbit in which data were acquired, while the last two digits denote the number of the OST that was used during data acquisition
mmm = OST line #, 000-999, 3-digit number the OST line being used during data acquisition
aa = operative mode
RO = receive only
SS = sub-surface sounding
bb = 2-digit number, 01-21, associated with the number of pre-summed echoes in a data block and to the bit resolution of each sample, see table below
ppp = 3-digit number corresponding to the integer part of the Pulse Repetition Frequency (PRF) value used in acquiring data
335 = 335.12 Hz
350 = 350.14 Hz
387 = 387.60 Hz
670 = 670.24 Hz
700 = 700.28 Hz
775 = 775.19 Hz
v = version, A-Z
In ODE, RDR products have the following Product IDs:
R_NNNNNNN_MMM_AABB_PPP_V
Table of Operative mode 2-digit numbers
|
Instrument Mode |
Number of Pre-summed Echoes |
Bits per Sample |
|---|---|---|
|
01 |
32 |
8 |
|
02 |
28 |
6 |
|
03 |
16 |
4 |
|
04 |
8 |
8 |
|
05 |
4 |
6 |
|
06 |
2 |
4 |
|
07 |
1 |
8 |
|
08 |
32 |
6 |
|
09 |
28 |
4 |
|
10 |
16 |
8 |
|
11 |
8 |
6 |
|
12 |
4 |
4 |
|
13 |
2 |
8 |
|
14 |
1 |
6 |
|
15 |
32 |
4 |
|
16 |
28 |
8 |
|
17 |
16 |
6 |
|
18 |
8 |
4 |
|
19 |
4 |
8 |
|
20 |
2 |
6 |
|
21 |
1 |
4 |