Chandrayaan-1 MRFFR Packetized Data Record (PDR)

PDR – Packetized Data Product

Instrument: Forerunner

PDS3 Data Set ID: CH1-ORB-L-MRFFR-1-PDR-V1.0DOI: 10.17189/1519033

For more information about Forerunner PDR products, see the PDR Data Set Description.

For more information about all Forerunner products, see the Data Product SIS.

The Forerunner (MRFFR) Packetized Data Product (PDR) data products are in the form of raw binary telemetry that have been extracted from frames downlinked from the instrument. PDRs have duplications removed and include any ancillary information needed to understand what is in a given packet. They are retained so that future researchers can reproduce the higher-level products if they so desire. These data will not be reformatted or processed further and are delivered to the PDS with detached minimal PDS labels. Because the higher-level products can be reprocessed as often as desired, there may be a one-to-many relationship from a raw data product to a processed data product.

The formats of these packets are identical, but their contents differ. Each of these packets is composed of five segments: the Consultative Committee for Space Data Systems (CCSDS) Primary Header which contains packet identification information, the CCSDS Secondary Header which contains the packet time stamp, the Science Header which contains associated metadata, the Science Data which contains the data samples, and a trailer (Other Data) which contains transmission information.

The science data are time-ordered and consist of Vertical (V) or Horizontal (H) polarization channel samples contained within a pulse. The packets will contain either H or V channel data, never both in the same packet.

MRFFR PDR products have the following file names:

FSB_nnnnn_Rtt_XrB_aadooo_Vz.xxx (with one detached PDS label for the two data files and one detached PDS label for the housekeeping product)

where:

F = instrument = Forerunner

S = frequency band = S-band

B = radar mode = Baseline SAR

nnnnn = orbit number in which data acquisition began, numeric range 00001…99999

R = processing level = Raw PDR

tt = file type

PD = Packetized Data Records

HK = Instrument Housekeeping data

X = projection = N/A

r = pixel resolution bin scale in pixels per degree (ppd) and meters/pixel (mpd)

H = 128 ppd, 237 mpd

I = 256 ppd, 118 mpd

B = bit type and scaling = Byte

aa = lunar center latitude to nearest whole degree, numeric range 00…90, XX = N/A or Unknown

d = hemisphere of latitude

N = North latitude

S = South latitude

X = N/A

ooo = lunar center longitude to nearest whole degree, numeric range 000…359

z = product version number, numeric range 1…9

xxx = file extension

DAT = Unformatted binary data (e.g., raw files)

TXT = Unstructured text data (e.g., parameter files)

CSV = Comma Separated Value text files (housekeeping)

 

Note:

The Packetized Data Records (PDR) that are associated with the PDS3 Data Set ID (CH1-ORB-L-MRFFR-1-PDR-V1.0) were not migrated to PDS4. They are telemetry data in a format that could not be converted to a PDS4-compliant format. Given that PDR data share the same Data Set ID as the housekeeping data in PDS3, they have been cross-referenced in the product details page of the housekeeping data in PDS4. Additionally, a direct download link for the PDR data has been provided.