MRO GRS Experiment Data Record (EDR)

EDR – Experiment Data Record

Instrument: MRO Gravity/Radio Science

PDS Data Set ID: MRO-M-RSS-1-MAGR-V1.0DOI: 10.17189/1519443

For more information about Gravity and Radio Science EDRs, see the directory document page. See docinfo.txt for page contents.

The MRO Gravity/Radio Science (GRS) Experiment Data Record (EDR) from the Mars Reconnaissance Orbiter (MRO) Gravity Science (GS) contains either archival raw, partially processed, or ancillary/supporting radio science data acquired during the MRO mission. The radio observations were carried out using the MRO spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The complete data set was designed primarily to support generation of high-resolution gravity field models for Mars and secondarily for estimating density and structure of the Mars atmosphere. Of most interest are likely to be the Orbit Data Files and Radio Science Receiver files in the ODF and RSR directories, respectively, which provided the raw input to gravity and atmospheric investigations, as well as the ionospheric and tropospheric media calibration files in the ION and TRO directories respectively.

Two types of measurements were conducted, known as closed- and open-loop recordings. The closed-loop system used a phase-lock loop in the ground receiver to track the downlink signal, reporting both amplitude and frequency at rates typically of 1-10 times per second. In the open-loop system, the signal was simply converted to a baseband frequency range; the entire passband was sampled and recorded for later processing. Typical open-loop sampling rates for MRO were 1000 samples per second.

The data set includes three primary data types. Tracking and Navigation Service Data Files (TNFs) are the most primitive (and most voluminous) product of the closed-loop system. Orbit Data Files (ODFs) are compressed versions of TNFs, specifically targeted to spacecraft navigators and scientists interested in gravity fields. Radio Science Receiver records (RSRs) are the primary data type from the open-loop system.

The primary data files are accompanied by secondary data files. These files can be found in the ancillary directory. These include reconstructed C-Kernel (high-gain antenna – ACK, solar array – SCK, spacecraft – CCK) files, predicted C-Kernel files (high-gain antenna – ACP, solar array – SAK) files, Light-Time (LTF) files, Maneuver Performance Data Files (MPD), Ionosphere Calibration (ION) files, Small Forces Files (SFF), Earth Orientation Parameter Files (EOP), Downlink Frequency Files (DLF), Spacecraft/Planetary Ephemeris (SPK) files, Weather (WEA) files, and Troposphere Calibration (TRO) files.

The file naming convention for EDR products varies by data file type.