PDS_VERSION_ID = PDS3
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 80
OBJECT = TEXT
PUBLICATION_DATE = 2001-03-20
NOTE = "Software Interface Specification for
the Mars Global Surveyor Radio Science
Electron Density Profile (RSED) file.
Formatted for display or printing at
58 lines per page with up to 78
constant width characters per line."
END_OBJECT = TEXT
END
Stanford Center for Radar Astronomy
Mars Global Surveyor Project
Software Interface Specification
Ionospheric Electron Density Profile Data File
prepared by
Richard A. Simpson
Center for Radar Astronomy
Stanford University
Stanford, CA 94305-9515
650-723-3525
Version 1.0.1
20 March 2001
PREFACE
|====================================================================|
| |
| DOCUMENT CHANGE LOG |
| |
|====================================================================|
|REVISION|REVISION| SECTION | REMARKS |
| NUMBER | DATE | AFFECTED | |
|--------+--------+------------+-------------------------------------|
| 1.0 |00/08/09| All |Adapted from RSTP V2.0.5 SIS |
|--------+--------+------------+-------------------------------------|
| 1.0.1 |01/03/20| 2.1.1 |Repair typos: double period; change |
| | | 2.3 | "TP" and "temperature pressure" to |
| | | 4.2.1 | "ED" and "electron density"; correct|
| | | Fig 4-2 | line number for ^RSED_TABLE (twice).|
|====================================================================|
|====================================================================|
| |
| ITEMS TO BE DETERMINED |
| |
|====================================================================|
| REVISION | SECTION | ITEM DESCRIPTION | RESOLUTION |
| NUMBER | AFFECTED | | |
|----------+----------+------------------------+---------------------|
| 1.0 | | | |
|====================================================================|
Distribution
PDS/JPL
J. Wilf...............171-264 joel.wilf@jpl.nasa.gov
M. Martin.............171-264 michael.d.martin@jpl.nasa.gov
PDS/NMSU
R. Beebe......Dept. Astronomy rbeebe@nmsu.edu
L. Huber......Dept. Astronomy lhuber@nmsu.edu
PDS/PPI
R.J. Walker...........IGPP UCLA rwalker@igpp.ucla.edu
S.P. Joy..............IGPP UCLA sjoy@igpp.ucla.edu
Stanford University
R. Simpson........Packard 332 rsimpson@magellan.stanford.edu
L. Tyler..........Packard 331 len.tyler@stanford.edu
D.P. Hinson.........Packard 333 hinson@nimbus.stanford.edu
J.D. Twicken........Packard 321 joe@neptune.stanford.edu
Jet Propulsion Laboratory
S.W. Asmar...........MS 264-860 sami.w.asmar@jpl.nasa.gov
A. Anabtawi........MS 264-860 aseel@godzilla.jpl.nasa.gov
R. Springer........MS 264-214 richard.j.springer@jpl.nasa.gov
R. Woo.............MS 238-725 richard@oberon.jpl.nasa.gov
Contents
Preface.............................................................ii
Document Change Log...............................................ii
Items to be Determined............................................ii
Distribution.....................................................iii
Contents..........................................................iv
Acronyms and Abbreviations.........................................v
1. General Description...............................................1
1.1. Overview......................................................1
1.2. Scope.........................................................1
1.3. Applicable Documents..........................................1
1.4. System Siting.................................................1
1.4.1. Interface Location and Medium.............................1
1.4.2. Data Sources, Transfer Methods, and Destinations..........1
1.4.3. Generation Method and Frequency...........................1
1.5. Assumptions and Constraints...................................2
1.5.1. Usage Constraints.........................................2
1.5.2. Priority Phasing Constraints..............................2
1.5.3. Explicit and Derived Constraints..........................2
1.5.4. Documentation Conventions.................................2
1.5.4.1. Data Format Descriptions..............................2
1.5.4.2. Time Standards........................................2
1.5.4.3. Coordinate Systems....................................3
1.5.4.4. Limits of This Document...............................3
1.5.4.5. Typographic Conventions...............................3
2. Interface Characteristics.........................................4
2.1. Hardware Characteristics and Limitations......................4
2.1.1. Special Equipment and Device Interfaces...................4
2.1.2. Special Setup Requirements................................4
2.2. Volume and Size...............................................4
2.3. Labeling and Identification...................................4
2.4. Interface Medium Characteristics..............................5
2.5. Failure Protection, Detection, and Recovery Procedures........5
2.6. End-of-File Conventions.......................................5
3. Access............................................................6
3.1. Programs Using the Interface..................................6
3.2. Synchronization Considerations................................6
3.2.1. Timing and Sequencing Considerations......................6
3.2.2. Effective Duration........................................6
3.2.3. Priority Interrupts.......................................6
3.3. Input/Output Protocols, Calling Sequences.....................6
4. Detailed Interface Specifications.................................7
4.1. Structure and Organization Overview...........................7
4.2. Detached PDS Label............................................7
4.2.1. Label Header..............................................7
4.2.2. Label Body................................................9
4.3. Data File.....................................................9
Appendix A. Example Label..........................................10
Appendix B. Example Data Object................ ...................18
Figures
4-2. RSED Label Header.............................................7
Acronyms and Abbreviations
ANSI American National Standards Institute
ARCDR Altimetry and Radiometry Composite Data Record
ASCII American Standard Code for Information Interchange
CCSDS Consultative Committee for Space Data Systems
CD Compact Disc
CNES Centre National d'Etudes Spatiales
dB Decibel
DSN Deep Space Network
EDH Electron Density High resolution (directory or file)
EDS Electron Density Standard resolution (directory or file)
FEA Front End Assembly
GSFC Goddard Space Flight Center
IEEE Institute of Electrical and Electronic Engineers
IAU International Astronomical Union
JPL Jet Propulsion Laboratory
J2000 IAU Official Time Epoch
K Degrees Kelvin
kB Kilobytes
km Kilometers
MB Megabytes
MGS Mars Global Surveyor
MO Mars Observer
NAIF Navigation and Ancillary Information Facility
NASA National Aeronautics and Space Administration
NAV Navigation Subsystem/Team
PDB Project Data Base
PDS Planetary Data System
RS Radio Science
RSED Radio Science Electron Density (profile)
RSS Radio Science Subsystem
RST Radio Science Team
SCET Space Craft Event Time
SIS Software Interface Specification
SOPC Science Operations Planning Computer
SPARC Sun Scaleable Processor Architecture
TBD To Be Determined
TDB Temps Dynamique Barycentrique - IAU Standard Ephemeris
Time
UTC Coordinated Universal Time
WO Write Once
1. General Description
1.1. Overview
This Software Interface Specification (SIS) describes Radio
Science Ionospheric Electron Density Profile (RSED) data files
from the Mars Global Surveyor (MGS) Mission. RSED files are created
at Stanford University and contain results of processing MGS radio
occultation data to obtain the structure of Mars' ionosphere [1].
The Mars Global Surveyor Mission is managed by the Jet Propulsion
Laboratory (JPL) for the National Aeronautics and Space
Administration (NASA).
1.2. Scope
The format and content specifications in this SIS apply to all
phases of the Mars Global Surveyor Mission for which the RSED is
produced.
1.3. Applicable Documents
[1] Tyler, G.L., G. Balmino, D.P. Hinson, W.L. Sjogren, D.E. Smith,
R. Woo, S.W. Asmar, M.J. Connally, C.L. Hamilton, and R.A. Simpson,
Radio Science Investigations with Mars Observer, J. Geophys. Res.,
97, 7759-7779, 1992.
[2] MO 642-321, Mars Global Surveyor Planetary Constants and Models,
JPL D-3444, November 1990.
[3] Planetary Science Data Dictionary, JPL D-7116, Rev. D, 15 July 1996.
[4] Planetary Data System Standards Reference, JPL D-7669, part 2,
24 July 1995.
1.4. System Siting
1.4.1. Interface Location and Medium
RSED files are created by the Stanford MGS RS processing system,
which consists of Sun Ultra 2, Ultra 5, and SPARC-10 workstations;
other computers; and associated peripherals.
1.4.2. Data Sources, Transfer Methods, and Destinations
RSED files are created on the Stanford MGS RS processing system.
They are distributed electronically by the MGS RS server and are written
to compact disc write-once (CD-WO) volumes for archive with the Planetary
Data System (PDS).
1.4.3. Generation Method and Frequency
EDS products are generated by reformatting and manipulating
output files from Stanford programs. Each RSED contains data from
one occultation event. RSED files are generated when the data for the
appropriate orbits become available.
1.5. Assumptions and Constraints
1.5.1. Usage Constraints
None.
1.5.2. Priority Phasing Constraints
None.
1.5.3. Explicit and Derived Constraints
None.
1.5.4. Documentation Conventions
1.5.4.1. Data Format Descriptions
The reference data unit is the byte. Data may be stored in
fields with various sizes and formats, viz. one-, two-, and four-byte
binary integers, four- and eight-byte binary floating-point numbers,
and character strings. Data are identified throughout this document
as
char 8 bits character
uchar 8 bits integer
short 16 bits integer
long 32 bits integer
float 32 bits floating point (sign, exponent, and
mantissa)
double 64 bits floating point (sign, exponent, and
mantissa)
u (prefix) unsigned (as with ulong for
unsigned 32-bit integer)
other special data structures such as
time, date, etc. which are
described within this document
The detailed formats of the numeric fields are defined in Appendix A.
If a field is described as containing n bytes of ASCII
character string data, this implies that the leftmost (lowest
numbered) byte contains the first character, the next lowest byte
contains the second character, and so forth.
An array of n elements is written as array[n]; the first
element is array[0], and the last is array[n-1]. Array[n][m]
describes an n x m element array, with first element array[0][0],
second element array[0][1], and so forth.
1.5.4.2. Time Standards
RSED calculations use the January 1.5, 2000 epoch as the
standard time. Within the data files, all times are reported in
Universal Coordinated Time (UTC) as strings of 23 ASCII characters.
The time format is "YYYY-MM-DDThh:mm:ss.fff", where "-", "T", ":",
and "." are fixed delimiters; "YYYY" is the year "19nn" or "20nn";
"MM" is a two-digit month of year; "DD" is a two-digit day of month;
"T" separates the date and time segments of the string; "hh" is hour
of day; "mm" is the minutes of hour (00-59); "ss" is the seconds of
hour (00-59); and "fff" is in milliseconds. Optional suffix "Z"
explicitly indicates use of the UTC reference.
The date format is "YYYY-MM-DD", where the components are
defined as above.
1.5.4.3. Coordinate Systems
The RSED uses the Areocentric fixed body coordinate system [2].
1.5.4.4. Limits of This Document
This document applies only to the RSED product.
1.5.4.5. Typographic Conventions
This document has been formatted for simple electronic file
transfer and display. Line lengths are limited to 80 ASCII
characters, including line delimiters. No special fonts or structures
are included within the file. Constant width characters are assumed
for display.
2. Interface Characteristics
2.1. Hardware Characteristics and Limitations
2.1.1. Special Equipment and Device Interfaces
RSED files are created on Stanford MGS computers using
IEEE formats and are stored on CD-WO media.
2.1.2. Special Setup Requirements
None.
2.2. Volume and Size
A standard resolution RSED file (Electron Density Standard, or EDS)
requires about 15 kB for the label and 5 kB for the data -- or 20 kB total.
A high resolution file (EDH) has the same size label and requires about
50 kB for the data.
2.3. Labeling and Identification
Each file has a name which describes its contents. The name
includes the following structure which uniquely identifies it among
Mars Global Surveyor Radio Science products:
ydddhmmC.EDx
where
y is the least significant digit of the year
ddd is the day of year
h is a one character representation of the hour on which
data acquisition began (A = 00, B = 01, ... X = 23)
mm is the minute on which the occultation data
acquisition began (see note below for convention
when two acquisition systems began at the same
minute)
C is a single character denoting the version of the file
(first version is "A", second is "B", etc.)
"ED" identifies the file as containing a Radio Science
electron density profile,
"x" indicates resolution
"S" standard resolution
"H" high resolution
Note: Some occultations may be captured by more than one ground
station with recording beginning at the same time. In
those cases the least significant digit of mm will be
modified as follows.
Least Significant Digit of "mm" for Coincident Files
First Data File Second Data File Third Data File
--------------- ---------------- ---------------
0 A K
1 B L
2 C M
3 D N
4 E O
5 F P
6 G Q
7 H R
8 I S
9 J T
2.4. Interface Medium Characteristics
RSED products are electronic files.
2.5. Failure Protection, Detection, and Recovery Procedures
None.
2.6. End-of-File Conventions
End of file labeling complies with standards for the media in use.
3. Access
3.1. Programs Using the Interface
Data contained in RSED files will be accessed by programs at the
home institutions of Mars Global Surveyor and other investigators.
Those programs cannot be identified here.
3.2. Synchronization Considerations
3.2.1. Timing and Sequencing Considerations
N/A
3.2.2. Effective Duration
N/A
3.2.3. Priority Interrupts
None.
3.3. Input/Output Protocols, Calling Sequences
None.
4. Detailed Interface Specifications
4.1. Structure and Organization Overview
The RSED is a file generated by Radio Science data reduction
and analysis software at Stanford University. Each RSED file is
accompanied by a detached PDS label.
4.2. Detached PDS Label
The detached PDS label has two parts -- a header and body.
The header contains information about the origin of the file and
its general characteristics such as record type and size. The
body is a complete bit-level definition of the RSED file; it
includes object definitions for each component of the RSED file.
Each detached PDS label is constructed of ASCII records;
each record contains exactly 80 characters. The last two characters
in each record are the carriage-return (ASCII 13) and line-feed
(ASCII 10) characters.
4.2.1 Label Header
The structure of the label file header is illustrated in
Figure 4-2. Keyword definitions are given below. An example of a
complete label file is given in Appendix B.
|====================================================================|
| |
| Figure 4-2. RSED Label Header |
| |
|====================================================================|
| |
| PDS_VERSION_ID = PDS3 |
| RECORD_TYPE = FIXED_LENGTH |
| RECORD_BYTES = 56 |
| FILE_RECORDS = nnn |
| ^RSED_HDR_TABLE = ("ydddhmmC.EDx",1) |
| ^RSED_TABLE = ("ydddhmmC.EDx",6) |
| INSTRUMENT_HOST_NAME = "MARS GLOBAL SURVEYOR" |
| TARGET_NAME = "MARS" |
| INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" |
| DATA_SET_ID = "MGS-M-RSS-5-SDP-Vn.m" |
| PRODUCT_ID = "ydddhmmC.EDx" |
| PRODUCT_RELEASE_DATE = YYYY-MM-DD |
| DESCRIPTION = "cccccccccccccccccc" |
| START_TIME = YYYY-MM-DDThh:mm:ss.fffZ |
| STOP_TIME = YYYY-MM-DDThh:mm:ss.fffZ |
| SOFTWARE_NAME = "ccccccc;Vn.m" |
| PRODUCT_CREATION_TIME = YYYY-MM-DDThh:mm:ss.fffZ |
| PRODUCER_ID = "MGS RST" |
| |
|====================================================================|
PDS_VERSION_ID = The version of the Planetary Data System for
which these data have been prepared (set to
PDS3 by agreement between the Mars Global
Surveyor Project and PDS).
RECORD_TYPE = The type of record. Set to "FIXED_LENGTH"
to indicate that all logical records have
the same length.
RECORD_BYTES = The number of bytes per (fixed-length)
record. Set to "56" for the RSED.
FILE_RECORDS = The number of records in the RSED file;
instance dependent.
^RSED_HDR_TABLE = File name and record number at which
RSED_HDR_TABLE begins. The file naming
convention is defined in Section 2.3;
record number is 1.
^RSED_TABLE = File name and record number at which
RSED_TABLE begins. The file naming
convention is defined in Section 2.3;
record number is 6.
INSTRUMENT_HOST_NAME = Name of the spacecraft; set to
"MARS GLOBAL SURVEYOR".
TARGET_NAME = A character string which identifies the
target body. For MGS RSED files, the
character string "MARS".
INSTRUMENT_NAME = Name of the instrument; set to "RADIO
SCIENCE SUBSYSTEM".
DATA_SET_ID = Identifier for the data set of which this
RSED product is a member. Set to "MGS-M-
RSS-5-SDP-Vn.m" for the RSED, where "Vn.m"
indicates the version number of the data
set.
PRODUCT_ID = A unique identifier for the product within
the MGS RST collection of data sets. The
naming convention is defined in Section 2.3.
PRODUCT_RELEASE_DATE = The date at which the product may be
released by the Mars Global Surveyor Project
to the Planetary Data System; entered in the
format "YYYY-MM-DD", where components are
defined in Section 1.5.4.2.
DESCRIPTION = A short description of the RSED product.
START_TIME = The Earth Receive Time at which the first
sample was acquired expressed in the format
"YYYY-MM-DDThh:mm:ss.fff" where the
components are defined in Section 1.5.4.2.
STOP_TIME = The Earth Receive Time at which the last
sample was acquired expressed in the format
"YYYY-MM-DDThh:mm:ss.fff" where the
components are defined in Section 1.5.4.2.
SOFTWARE_NAME = The name and version number of the program
creating this RSED file; expressed as a
character string in the format
"PROGRAM_NAME;n.mm" where "PROGRAM_NAME" is
the name of the software and "n.mm" is the
version number.
PRODUCT_CREATION_TIME = The time at which this RSED was created;
expressed in the format "YYYY-MM-
DDThh:mm:ss.fff" where the components are
defined in Section 1.5.4.2.
PRODUCER_ID = The entity responsible for creation of the
RSED product; set to "MGS RST".
4.2.2 Label Body
The body of the PDS label completely defines both the format and
the content of the RSED file. It is written as a pair of OBJECT
definitions -- one for the RSED header table and one for the RSED data
table. An example of a complete label is given in Appendix B. Since
the format and content of the RSED file may vary over the course of the
MGS mission, users should always refer to the accompanying label for
current specifications of the RSED file.
4.3. Data File
The RSED data file contains ionospheric profile measurements
from one occultation event. It comprises two PDS TABLE objects --
one containing summary information for an occultation and the
other containing the electron density profile itself. The
structure and content of each RSED file is defined by the accompanying
detached PDS label (see Section 4.2 and Appendix B). Note that the
format and content of the RSED file may evolve over the course of the
MGS mission; users should always refer to the accompanying PDS label
for current format and content specifications.
Appendix A. Example RSED Label
The following is an example label for a Radio Science
Electron Density (RSED) file. In Appendix B, the corresponding
data object is shown.
PDS_VERSION_ID = PDS3
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 56
FILE_RECORDS = 87
^RSED_HDR_TABLE = ("8358D47A.EDS",1)
^RSED_TABLE = ("8358D47A.EDS",6)
INSTRUMENT_HOST_NAME = "MARS GLOBAL SURVEYOR"
TARGET_NAME = "MARS"
INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM"
DATA_SET_ID = "MGS-M-RSS-5-SDP-V1.0"
PRODUCT_ID = "8358D47A.EDS"
PRODUCT_RELEASE_DATE = 2000-08-08
DESCRIPTION = "This file contains an ionospheric
electron density profile derived from MGS radio occultation data.
Raw samples of DSN receiver output were corrected for observing
conditions and converted to bending angle as a function of impact
parameter. These results were then inverted to refractive index
as a function of radius via an Abel transform. Electron number
density was obtained from refractive index using a conversion
formula appropriate to the measurement frequency (8423 MHz).
See Hinson et al. (J. Geophys. Res., 104, 26997-27012, 1999;
J. Geophys. Res., 103, 9505-9520, 1998) for more details."
START_TIME = 1998-12-24T03:47:00Z
STOP_TIME = 1998-12-24T04:08:00Z
SOFTWARE_NAME = "EDS; V1.1"
PRODUCT_CREATION_TIME = 2000-08-08T23:11:36Z
PRODUCER_ID = "MGS RST"
OBJECT = RSED_HDR_TABLE
ROWS = 1
COLUMNS = 25
ROW_BYTES = 280
INTERCHANGE_FORMAT = ASCII
DESCRIPTION = "The RSED header contains ancillary data
associated with ionospheric electron density profiles. Each header
includes a single row of 25 data columns delimited by ASCII commas
(263 total bytes), 15 ASCII blank characters to pad out the record,
and an ASCII carriage-return line-feed pair at the end."
OBJECT = COLUMN
NAME = "START TIME"
COLUMN_NUMBER = 1
DATA_TYPE = TIME
START_BYTE = 1
BYTES = 23
UNIT = "N/A"
DESCRIPTION = "The Earth Receive Time at which
the first radio occultation data sample was acquired."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "STOP TIME"
COLUMN_NUMBER = 2
DATA_TYPE = TIME
START_BYTE = 25
BYTES = 23
UNIT = "N/A"
DESCRIPTION = "The Earth Receive Time at which
the last radio occultation data sample was acquired."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "OCCULTATION TIME"
COLUMN_NUMBER = 3
DATA_TYPE = TIME
START_BYTE = 49
BYTES = 23
UNIT = "N/A"
DESCRIPTION = "The time at Mars when the
experiment was sounding the ionosphere at 130 km altitude.
This is computed by subtracting the Mars-to-Earth light time
from the appropriate Earth Receive Time."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "ORBIT NUMBER"
COLUMN_NUMBER = 4
DATA_TYPE = ASCII_INTEGER
START_BYTE = 73
BYTES = 5
FORMAT = "I5"
UNIT = "N/A"
DESCRIPTION = "Orbit number from which the data
were acquired; set to zero if not known."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "DSN ANTENNA NUMBER"
COLUMN_NUMBER = 5
DATA_TYPE = ASCII_INTEGER
START_BYTE = 79
BYTES = 2
FORMAT = "I2"
UNIT = "N/A"
DESCRIPTION = "Number of the DSN antenna used
to collect the data (e.g., 14, 43, 65, ...)."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "RAY PATH DIRECTION"
COLUMN_NUMBER = 6
DATA_TYPE = ASCII_REAL
START_BYTE = 82
BYTES = 6
FORMAT = "F6.1"
UNIT = "DEGREE"
DESCRIPTION = "The angle between local north and
the direction of radio signal propagation at the point of
closest approach to Mars. Angle is measured positive from
local north toward local east. A signal traveling from west
toward east would have a ray-path-direction of 90 degrees."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "ANGLE FROM DIAMETRIC"
COLUMN_NUMBER = 7
DATA_TYPE = ASCII_REAL
START_BYTE = 89
BYTES = 6
FORMAT = "F6.1"
UNIT = "DEGREE"
DESCRIPTION = "Angle at which the spacecraft
rises or sets behind the planet limb, measured clockwise from
the planet radial direction as viewed from Earth. An angle-
from-diametric equal to zero indicates a diametric occultation
with motion of the ray away from the surface (e.g., occultation
egress). A value near 180 degrees is a nearly diametric ingress
occultation."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "LATITUDE OF PROFILE"
COLUMN_NUMBER = 8
DATA_TYPE = ASCII_REAL
START_BYTE = 96
BYTES = 7
FORMAT = "F7.3"
UNIT = "DEGREE"
DESCRIPTION = "Areocentric (north) latitude
where the experiment sounded the ionosphere at 130 km altitude."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SIGMA LATITUDE"
COLUMN_NUMBER = 9
DATA_TYPE = ASCII_REAL
START_BYTE = 104
BYTES = 6
FORMAT = "F6.3"
UNIT = "DEGREE"
DESCRIPTION = "One standard deviation uncertainty
in LATITUDE OF PROFILE. This value also serves as an estimate
of the uncertainty in LATITUDE in RSED_TABLE. Set to -9.999 if
not known."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "LONGITUDE OF PROFILE"
COLUMN_NUMBER = 10
DATA_TYPE = ASCII_REAL
START_BYTE = 111
BYTES = 8
FORMAT = "F8.3"
UNIT = "DEGREE"
POSITIVE_LONGITUDE_DIRECTION = "EAST"
DESCRIPTION = "Areocentric east longitude where
the experiment sounded the ionosphere at 130 km altitude."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SIGMA LONGITUDE"
COLUMN_NUMBER = 11
DATA_TYPE = ASCII_REAL
START_BYTE = 120
BYTES = 6
FORMAT = "F6.3"
UNIT = "DEGREE"
DESCRIPTION = "One standard deviation uncertainty
in LONGITUDE OF PROFILE. This value also serves as an estimate
of the uncertainty in LONGITUDE in RSED_TABLE. Set to -9.999 if
not known."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SUB-SOLAR LATITUDE"
COLUMN_NUMBER = 12
DATA_TYPE = ASCII_REAL
START_BYTE = 127
BYTES = 6
FORMAT = "F6.2"
UNIT = "DEGREE"
DESCRIPTION = "Areocentric (north) latitude of
the sun at OCCULTATION TIME."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SUB-SOLAR LONGITUDE"
COLUMN_NUMBER = 13
DATA_TYPE = ASCII_REAL
START_BYTE = 134
BYTES = 7
FORMAT = "F7.2"
UNIT = "DEGREE"
POSITIVE_LONGITUDE_DIRECTION = "EAST"
DESCRIPTION = "Areocentric east longitude of the
sun in body fixed coordinates at OCCULTATION TIME."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SOLAR LONGITUDE"
COLUMN_NUMBER = 14
DATA_TYPE = ASCII_REAL
START_BYTE = 142
BYTES = 6
FORMAT = "F6.2"
UNIT = "DEGREE"
DESCRIPTION = "Value of the angle between the
Mars-Sun line at OCCULTATION TIME and the Mars-Sun line at the
Mars vernal equinox. Measured positive with increasing time
following the vernal equinox. Sometimes denoted L-sub-s."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SPACECRAFT TO LIMB DISTANCE"
COLUMN_NUMBER = 15
DATA_TYPE = ASCII_REAL
START_BYTE = 149
BYTES = 9
FORMAT = "E9.3"
UNIT = "METER"
DESCRIPTION = "Distance along ray path from
spacecraft to point of closest approach to Mars. Measured
at time when experiment was sounding the ionosphere at 130 km
altitude."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SPACECRAFT TO DSN DISTANCE"
COLUMN_NUMBER = 16
DATA_TYPE = ASCII_REAL
START_BYTE = 159
BYTES = 9
FORMAT = "E9.3"
UNIT = "METER"
DESCRIPTION = "Distance from spacecraft to DSN
receiving antenna at time when experiment was sounding the
ionosphere at 130 km altitude."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "MARS TO SUN DISTANCE"
COLUMN_NUMBER = 17
DATA_TYPE = ASCII_REAL
START_BYTE = 169
BYTES = 9
FORMAT = "E9.3"
UNIT = "METER"
DESCRIPTION = "Distance from Mars to Sun
at OCCULTATION TIME."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "LOCAL TRUE SOLAR TIME"
COLUMN_NUMBER = 18
DATA_TYPE = ASCII_REAL
START_BYTE = 179
BYTES = 6
FORMAT = "F6.3"
UNIT = "HOUR"
DESCRIPTION = "Local true solar time (LTST) at the
time and location of the occultation measurement. LTST at the
sub-solar longitude is defined as 12 solar hours. LTST on other
meridians changes by one solar hour for each 15 degree increment
in longitude. Thus, LTST for the occultation measurement is
given by 12 + (LONGITUDE_OF_PROFILE - SUB-SOLAR_LONGITUDE)/15."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SOLAR ZENITH ANGLE"
COLUMN_NUMBER = 19
DATA_TYPE = ASCII_REAL
START_BYTE = 186
BYTES = 6
FORMAT = "F6.2"
UNIT = "DEGREE"
DESCRIPTION = "Angle between the direction to Sun
and local vertical direction on Mars at time and location of the
occultation measurement."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SUN-EARTH-SPACECRAFT ANGLE"
COLUMN_NUMBER = 20
DATA_TYPE = ASCII_REAL
START_BYTE = 193
BYTES = 5
FORMAT = "F5.1"
UNIT = "DEGREE"
DESCRIPTION = "Approximate angle between Sun and
spacecraft as viewed from Earth during experiment."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "DSN ELEVATION ANGLE"
COLUMN_NUMBER = 21
DATA_TYPE = ASCII_REAL
START_BYTE = 199
BYTES = 5
FORMAT = "F5.1"
UNIT = "DEGREE"
DESCRIPTION = "Approximate angle between
direction to spacecraft and local horizon at DSN receiving
antenna during experiment."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "GRAVITY FIELD MODEL"
COLUMN_NUMBER = 22
DATA_TYPE = CHARACTER
START_BYTE = 206
BYTES = 12
FORMAT = "A12"
UNIT = "N/A"
DESCRIPTION = "File name of gravity field spherical
harmonic model used in defining reference areoid."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "PCK FILE NAME"
COLUMN_NUMBER = 23
DATA_TYPE = CHARACTER
START_BYTE = 221
BYTES = 12
FORMAT = "A12"
UNIT = "N/A"
DESCRIPTION = "File name of the NAIF Planetary
Constants File used in this retrieval and calculation (name
of the PCK file as stored in the MGS RST data system)."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "TRAJECTORY FILE NAME"
COLUMN_NUMBER = 24
DATA_TYPE = CHARACTER
START_BYTE = 236
BYTES = 12
FORMAT = "A12"
UNIT = "N/A"
DESCRIPTION = "File name of the spacecraft and
planetary ephemeris file used in this retrieval and calculation
(name of the file as stored in the MGS RST data system)."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SPACECRAFT ATTITUDE FILE NAME"
COLUMN_NUMBER = 25
DATA_TYPE = CHARACTER
START_BYTE = 251
BYTES = 12
FORMAT = "A12"
UNIT = "N/A"
DESCRIPTION = "File name of the spacecraft
attitude file used in this retrieval and calculation (name
of the file as stored in the MGS RST data system). Left
blank if not known or no attitude file was used."
END_OBJECT = COLUMN
END_OBJECT = RSED_HDR_TABLE
OBJECT = RSED_TABLE
ROWS = 82
COLUMNS = 6
ROW_BYTES = 56
INTERCHANGE_FORMAT = ASCII
DESCRIPTION = "Table contains radio science ionospheric
electron density profile. Each row in the table contains
data for 6 columns delimited by ASCII commas (54 bytes total)
and an ASCII carriage-return line-feed pair at the end."
OBJECT = COLUMN
NAME = "RADIUS"
COLUMN_NUMBER = 1
DATA_TYPE = ASCII_REAL
START_BYTE = 1
BYTES = 8
FORMAT = "F8.0"
UNIT = "METER"
DESCRIPTION = "Measurement radius."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "ALTITUDE"
COLUMN_NUMBER = 2
DATA_TYPE = ASCII_REAL
START_BYTE = 10
BYTES = 7
FORMAT = "F7.0"
UNIT = "METER"
DESCRIPTION = "Altitude of measurement above
reference areoid. The reference areoid is the equipotential
surface whose mean equatorial radius is 3,396,000 m."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "LATITUDE"
COLUMN_NUMBER = 3
DATA_TYPE = ASCII_REAL
START_BYTE = 18
BYTES = 7
FORMAT = "F7.3"
UNIT = "DEGREE"
DESCRIPTION = "Areocentric (north) latitude of
measurement."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "LONGITUDE"
COLUMN_NUMBER = 4
DATA_TYPE = ASCII_REAL
START_BYTE = 26
BYTES = 8
FORMAT = "F8.3"
UNIT = "DEGREE"
POSITIVE_LONGITUDE_DIRECTION = "EAST"
DESCRIPTION = "Areocentric (east) longitude of
measurement in body fixed coordinates."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "ELECTRON NUMBER DENSITY"
COLUMN_NUMBER = 5
DATA_TYPE = ASCII_REAL
START_BYTE = 35
BYTES = 11
FORMAT = "E11.4"
UNIT = "1 PER CUBIC METER"
DESCRIPTION = "Electron number density of the
ionosphere at RADIUS, LATITUDE, LONGITUDE."
END_OBJECT = COLUMN
OBJECT = COLUMN
NAME = "SIGMA ELECTRON NUMBER DENSITY"
COLUMN_NUMBER = 6
DATA_TYPE = ASCII_REAL
START_BYTE = 47
BYTES = 8
FORMAT = "E8.2"
UNIT = "1 PER CUBIC METER"
DESCRIPTION = "One standard deviation uncertainty
in ELECTRON NUMBER DENSITY."
END_OBJECT = COLUMN
END_OBJECT = RSED_TABLE
END
Appendix B. Example Data Object
The RSED data object corresponding to the example label in Appendix A
is shown below. Lines are wrapped after column 60; that is, the first five
lines below correspond to RSED_HEADER_TABLE.
1998-12-24T03:47:00.000,1998-12-24T04:08:00.000,1998-12-24T0
3:48:05.698, 917,54, 23.3,-173.3, 64.725,-9.999, 325.191,-
9.999, 24.17, 81.25, 74.12,7.592E+06,2.348E+11,2.492E+11, 4
.263, 78.40, 77.7, 29.2,"GGM50A02.SHA","PCK3223A.TPC","83570
07A.SPK"," "
3585856.,204604., 64.785, 325.070, 7.4064E+09,1.96E+09
3584499.,203248., 64.784, 325.072, 6.9255E+09,1.96E+09
3583142.,201890., 64.783, 325.074, 7.2512E+09,1.97E+09
3581785.,200532., 64.781, 325.076, 8.1599E+09,1.97E+09
3580427.,199175., 64.781, 325.078, 9.3110E+09,1.98E+09
3579071.,197818., 64.779, 325.080, 9.2210E+09,1.98E+09
3577713.,196460., 64.778, 325.083, 9.5889E+09,1.99E+09
3576355.,195102., 64.777, 325.085, 1.0358E+10,1.99E+09
3574997.,193744., 64.776, 325.087, 1.0867E+10,2.00E+09
3573640.,192386., 64.775, 325.089, 1.0540E+10,2.00E+09
3572281.,191027., 64.774, 325.091, 1.0995E+10,2.01E+09
3570922.,189668., 64.773, 325.093, 1.1866E+10,2.01E+09
3569564.,188310., 64.772, 325.095, 1.1896E+10,2.02E+09
3568205.,186950., 64.771, 325.098, 1.3372E+10,2.02E+09
3566847.,185592., 64.770, 325.100, 1.3807E+10,2.02E+09
3565487.,184232., 64.769, 325.102, 1.5042E+10,2.03E+09
3564128.,182873., 64.768, 325.104, 1.5756E+10,2.04E+09
3562768.,181513., 64.766, 325.106, 1.6840E+10,2.04E+09
3561409.,180153., 64.766, 325.108, 1.7441E+10,2.04E+09
3560049.,178793., 64.764, 325.111, 1.7925E+10,2.05E+09
3558689.,177433., 64.763, 325.113, 1.9342E+10,2.05E+09
3557329.,176073., 64.762, 325.115, 2.0442E+10,2.06E+09
3555968.,174712., 64.761, 325.117, 2.2005E+10,2.06E+09
3554608.,173351., 64.760, 325.119, 2.2833E+10,2.07E+09
3553247.,171990., 64.759, 325.122, 2.4355E+10,2.07E+09
3551887.,170630., 64.758, 325.124, 2.4939E+10,2.08E+09
3550525.,169268., 64.757, 325.126, 2.6543E+10,2.08E+09
3549165.,167907., 64.756, 325.128, 2.7830E+10,2.09E+09
3547804.,166545., 64.755, 325.130, 2.8612E+10,2.09E+09
3546442.,165184., 64.754, 325.133, 2.9632E+10,2.10E+09
3545080.,163821., 64.752, 325.135, 3.1625E+10,2.10E+09
3543718.,162459., 64.751, 325.137, 3.3247E+10,2.10E+09
3542356.,161097., 64.750, 325.139, 3.4667E+10,2.11E+09
3540994.,159734., 64.749, 325.142, 3.6925E+10,2.11E+09
3539632.,158372., 64.748, 325.144, 3.8251E+10,2.12E+09
3538269.,157009., 64.747, 325.146, 4.0086E+10,2.12E+09
3536907.,155647., 64.746, 325.148, 4.1050E+10,2.13E+09
3535544.,154284., 64.745, 325.151, 4.2410E+10,2.13E+09
3534181.,152920., 64.744, 325.153, 4.4744E+10,2.14E+09
3532818.,151557., 64.743, 325.155, 4.7328E+10,2.14E+09
3531454.,150193., 64.742, 325.157, 4.9818E+10,2.15E+09
3530090.,148829., 64.740, 325.160, 5.2415E+10,2.15E+09
3528726.,147465., 64.739, 325.162, 5.5153E+10,2.16E+09
3527363.,146101., 64.738, 325.164, 5.7673E+10,2.16E+09
3525998.,144736., 64.737, 325.166, 6.1499E+10,2.16E+09
3524634.,143371., 64.736, 325.169, 6.4803E+10,2.17E+09
3523269.,142006., 64.735, 325.171, 6.8664E+10,2.17E+09
3521904.,140641., 64.734, 325.173, 7.3224E+10,2.18E+09
3520539.,139276., 64.733, 325.176, 7.7823E+10,2.18E+09
3519174.,137911., 64.732, 325.178, 8.1539E+10,2.19E+09
3517809.,136545., 64.731, 325.180, 8.5564E+10,2.19E+09
3516444.,135180., 64.729, 325.183, 8.9066E+10,2.20E+09
3515080.,133816., 64.728, 325.185, 9.1168E+10,2.20E+09
3513716.,132452., 64.727, 325.187, 9.0971E+10,2.20E+09
3512353.,131088., 64.726, 325.189, 8.8457E+10,2.21E+09
3510989.,129724., 64.725, 325.192, 8.4492E+10,2.21E+09
3509626.,128361., 64.724, 325.194, 7.8340E+10,2.22E+09
3508263.,126998., 64.723, 325.196, 6.9376E+10,2.22E+09
3506899.,125633., 64.722, 325.199, 6.0907E+10,2.23E+09
3505533.,124267., 64.720, 325.201, 5.3921E+10,2.23E+09
3504168.,122902., 64.719, 325.203, 4.6608E+10,2.24E+09
3502801.,121535., 64.718, 325.206, 4.0496E+10,2.24E+09
3501433.,120167., 64.717, 325.208, 3.7052E+10,2.24E+09
3500065.,118798., 64.716, 325.210, 3.5255E+10,2.25E+09
3498698.,117430., 64.715, 325.213, 3.4039E+10,2.25E+09
3497329.,116062., 64.714, 325.215, 3.4114E+10,2.26E+09
3495961.,114693., 64.713, 325.217, 3.4642E+10,2.26E+09
3494594.,113326., 64.711, 325.220, 3.3882E+10,2.27E+09
3493226.,111958., 64.710, 325.222, 3.2730E+10,2.27E+09
3491859.,110591., 64.709, 325.224, 3.0439E+10,2.28E+09
3490491.,109222., 64.708, 325.227, 2.8864E+10,2.28E+09
3489123.,107854., 64.707, 325.229, 2.7244E+10,2.28E+09
3487755.,106486., 64.706, 325.232, 2.4927E+10,2.29E+09
3486387.,105118., 64.704, 325.234, 2.2307E+10,2.29E+09
3485019.,103749., 64.703, 325.236, 1.9512E+10,2.30E+09
3483650.,102380., 64.702, 325.239, 1.7185E+10,2.30E+09
3482280.,101010., 64.701, 325.241, 1.5582E+10,2.30E+09
3480912., 99641., 64.700, 325.244, 1.3559E+10,2.31E+09
3479542., 98271., 64.699, 325.246, 1.1760E+10,2.31E+09
3478173., 96902., 64.698, 325.248, 9.8087E+09,2.32E+09
3476804., 95532., 64.697, 325.251, 7.4068E+09,2.32E+09
3475433., 94161., 64.695, 325.253, 6.1376E+09,2.33E+09