Data Set Information
|
| DATA_SET_NAME |
MGS RADIO SCIENCE --
SCIENCE DATA PRODUCTS V1.0
|
| DATA_SET_ID |
MGS-M-RSS-5-SDP-V1.0
|
| NSSDC_DATA_SET_ID |
|
| DATA_SET_TERSE_DESCRIPTION |
Mars Global Surveyor reduced
radio science data.
|
| DATA_SET_DESCRIPTION |
Data Set Overview
=================
The Mars Global Surveyor (MGS) Radio Science (RS) Archive Data
Collection (ADC) of Science Data Products (SDP) includes data
products generated from radio occultation, gravity, and surface
reflection investigations conducted by members of the MGS Radio
Science Team (RST).
The archive includes both Standard Data Products (STDPs) and
Special Data Products (SPDPs). STDPs were defined prior to
Launch; with two exceptions, they were produced routinely
during the mission. The two exceptions were not created
regularly because suitable data were not available. SPDPs
were defined after Launch and/or were produced on an irregular
basis.
Radio occultation STDPs include temperature-pressure (T-p)
profiles, occultation summary files, and intensity power
spectra. T-p profiles were computed with standard vertical
resolution (approximately 200 m); an option to compute them
at high resolution (approximately 20 m, after correction for
diffraction effects) was never exercised. David Hinson at
Stanford University created all T-p profiles and occultation
summary files. Intensity power spectra were never computed
because no evidence for scintillations was ever found.
Richard Woo of the Jet Propulsion Laboratory (JPL) would
have created the intensity power spectra.
Gravity STDPs include spherical harmonic models, maps or images
of those models, and line-of-sight acceleration profiles.
Groups at the Goddard Space Flight Center (GSFC) under the
direction of David Smith and at JPL under the direction of
William Sjogren produced spherical harmonic models, maps, and
images. Sjogren's group also produced a small number of
line-of-sight acceleration profiles from pre-Mapping data
when periapsis was unusually low. Data collected during
Mapping showed little structure that was not captured in the
spherical harmonic model coefficients. A group at Centre
National d'Etudes Spatiales (CNES) under Georges Balmino also
worked with gravity data; but as of the end of the MGS mission
they had not delivered any gravity STDPs.
For more information on STDPs, see [TYLERETAL1992] and
[TYLERETAL2001].
Under certain conditions radio occultation data can be processed
to yield profiles of electron density in the ionosphere. SPDPs
include profiles at standard vertical resolution created at
Stanford University by David Hinson. An option to produce high
resolution ionospheric profiles was never exercised.
The surface reflection investigation was developed only after
the spacecraft was in Mars orbit. SPDPs include summary tables
of observing geometry, summary tables of reconstructed antenna
pointing at the spacecraft, summary tables of signal
characteristics, and images of signals in time-frequency space.
The reflected signals were collected over 1-2 minutes
immediately before an ingress occultation or immediately after
an egress occultation at nearly grazing incidence angles.
These products were generated by Richard Simpson of Stanford
University.
Simpson also conducted a handful of forward scattering bistatic
radar experiments at incidence angles 50-70 degrees. Received
power spectra in the two orthogonal circularly polarized
receiver channels are included in the final volume of the
archive.
NB: The complete set of radio occultation temperature-pressure
profiles (21243 files) has been extracted from these 38 volumes
and archived separately as data set MGS-M-RSS-5-TPS-V1.0.
Users interested solely in the T-p profiles may find this
archive (a single CD volume) to be more convenient. A single
occultation summary file accompanies the MGS-M-RSS-5-TPS-V1.0
data set.
As MORS_1038 was being written, a plan was in motion to
extract the electron density profiles into a second, separate
archive with the data set ID of MGS-M-RSS-5-EDS-V1.0.
The gravity results are not so easily repackaged. Although
the later gravity models are presumably better than the early
ones, the assumptions made in generating each model varied.
The legacy data (e.g., from Viking) used in the solution also
varied. In some cases a model with lower resolution (lower
degree and order) may be more satisfactory than a later one;
the user must make these decisions. Information in the
labels for the specific products may be helpful in deciding.
Parameters
==========
Temperature-pressure profiles are tables of atmospheric
temperature, pressure, and molecular number density versus
radius from Mars' center of mass. A header record prepended
to each table provides information on observing times and
geometry, surface conditions, and on files used in the data
processing. Header records from all of the T-p profiles
delivered at one time (typically every three months) are
collected together into a single occultation summary file.
Spherical harmonic models are tables of coefficients GM, Cmn,
and Smn -- as in equation (1) of [TYLERETAL1992]. These can
be used to represent gravitational potential of Mars, for
example. Both ASCII (data type SHA) and binary (data type
SHB) formats are defined, with the latter being preferred for
large files which also include covariance terms. Each file
contains up to four tables: a header table containing general
parameters for the model (gravitational constant, its
uncertainty, degree and order of the field, normalization
state, reference longitude, and reference latitude); a names
table, giving the order in which coefficients appear; a
coefficients table (degree m, order n, coefficients Cmn and
Smn, and their uncertainties); and a covariances table giving
the covariances of CijCmn, SijSmn, CijSmn, and SijCmn.
Radio Science Digital Map files are image representations
of gravity and other parameters. Free air gravity, geoid,
Bouguer anomaly, isostatic anomaly, and topographic values
may be displayed using this data type. Data are formatted
as PDS image objects.
The Line-of-Sight Acceleration Profile Data Record is a pair
of PDS tables. The first table contains header information
such as time and observing geometry, parameters used in
deriving acceleration from radio tracking measurements, and
first-order Keplerian orbit elements. The second table gives
spacecraft acceleration versus time. Also included at each
time is the spacecraft position in planetocentric coordinates.
Electron density profiles are very similar to temperature-
pressure profiles for the neutral atmosphere. Each is a
table of electron density versus radius from Mars' center of
mass. A header record prepended to each table provides
information on observing times and geometry and on files used
in the data processing. There is no summary file for the
electron density profiles delivered together.
Surface Reflection Tables list carrier frequency and power
and the estimated frequency and power in the surface echo.
Surface Reflection Images are series of power spectra
showing the progression of signal characteristics as a
function of time.
Surface Reflection Geometry tables summarize the observing
geometry at and near occultations at (typically) 1 second
intervals. Quantities include Earth receive time; the
transmit time (receive time corrected for one-way light time);
vectors to the spacecraft, Earth receiving station, and
several points on the surface; angles; and sensitivities of
some quantities to changes in assumed Mars radius. The
surface points include the specular point, the backscatter
point (the intersection of a line from the receiver through
the spacecraft to the surface), the raypath closest approach
point (the point where a line from the Earth to the spacecraft
is closest to the surface), and a user-defined 'target' on
the surface. For the surface reflection studies conducted
with MGS, only the specular point information is of interest.
The backscatter point is the point on Mars' disk behind the
spacecraft when viewed from Earth, while the raypath closest
approach point gives the latitude and longitude of the
occultation ray closest approach; the backscatter point and
the raypath closest approach point cannot exist simultaneously.
The 'target' point is meaningful only when a target has been
selected; it is usually set to a default value of (0.,0.).
Bistatic Radar Power Spectra are tables showing received power
versus frequency (rows) and time (columns).
Processing
==========
T-p profiles and ionosphere profiles are derived from raw
receiver output in several steps.
First, deterministic sources of frequency change are identified
and removed coherently. These included motion of the spacecraft,
motion of the Earth receiving station, drift of the UltraStable
Oscillator (USO), and relativistic effects associated with
gravity fields of solar system bodies. This leaves the carrier
signal at a known frequency except for phase drift associated
with passage of the radio ray through Mars' atmosphere and/or
ionosphere. Drift associated with passage through solar plasma
or the Earth's atmosphere or ionosphere is assumed to be
negligible over the time of a Mars occultation (approximately
two minutes).
Second, using an accurate reconstruction of the spacecraft
trajectory, the phase of the signal versus time is converted
into a measure of refraction angle versus impact parameter --
the perpendicular distance between the incoming raypath and the
center of curvature of the atmosphere.
Third, the index of refraction versus radius is obtained using
an Abel inversion [FJELDBOETAL1971]. From knowledge of the
composition of the atmosphere and laboratory measurements of
refractive index for major constituents, index of refraction
versus radius for the neutral atmosphere is converted to
vertical distribution of mass density.
Fourth, assuming hydrostatic equilibrium and an ideal gas law,
the mass density profile is converted to a profile of both
temperature and pressure for the neutral atmosphere.
For the ionosphere, refractive index versus radius is converted
to density of free electrons versus radius using a method
described by [YEH&LIU1972].
Spherical harmonic models, maps, and line-of-sight acceleration
profiles are derived from raw radio tracking data in several
steps.
The gravity field coefficients are obtained by solving systems
of equations with thousands of unknowns. Radio tracking data in
long arcs delimited by propulsive maneuvers, occultations, etc.
are used in solutions which are obtained iteratively and by
least squares.
Maps of free air gravity and other quantities are generated from
the spherical harmonic model(s) evaluated at regular grid
points.
Line-of-sight acceleration profiles are derived from single arcs
of radio tracking data. Doppler residuals with respect to a
specific spherical harmonic model are spline-fitted; the splines
are then differentiated analytically to obtain accelerations.
See [TYLERETAL1992] and [TYLERETAL2001] and references therein
for additional details on processing for the products listed
above.
Surface Reflection Geometry (SRG) tables are summaries of
observing geometry, typically at one second intervals. The
spacecraft-surface-Earth geometry is derived from an SPK (NAIF
spacecraft and planetary ephemeris) file.
Surface Reflection Antenna (SRA) tables are summaries of
high-gain antenna (HGA) pointing, typically at 1 second
intervals. The HGA pointing in J2000 is computed from
spacecraft attitude (TCK) and HGA gimbal (AGK) files; that
vector is then compared with the MGS-Earth vector in the SRG
file. Offset is listed as the total angle between the HGA
boresight and the MGS-Earth vector and in terms of the
components toward the surface and parallel to the limb.
The Surface Reflection Table (SRT) data are derived as follows.
(1) The occultation is located in time and its sense (ingress
or egress) is determined from the direction of change in the
receiver output: if ingress, the output should decrease; if
egress, the output should increase.
(2) Raw samples of receiver output are passed through
a digital 'equalizing' filter which flattens the output
spectral response over the central 80 percent of the
passband. The output is a string of double-precision
complex floating point time samples at the Nyquist sampling
rate (2500/s for data collected through mid-2001, 2000/s for
data collected starting in late 2001).
(3) 512-point power spectra (approximately 0.2 s each) are
computed around the transition point (1); approximately 30
spectra are saved on the occulted side of the transition and
270 are saved when the carrier is clearly visible (total of
300 spectra, spaced by 0.2 s and having 5 Hz frequency bins).
(4) A search within each spectrum for the bin with maximum
signal locates the carrier (when it is present).
(5) A second search within each spectrum for the strongest
signal at frequencies higher (lower) than the carrier if
ingress (egress) locates the surface echo. The surface echo
is transient, however, so not all results from this search
are valid. A predicted frequency curve (straight line) is
fitted to the DIFFERENCE between the peak echo bin and the
carrier bin; half of the points are thrown out (the worst
residuals). A new straight line is fitted to the remaining
points, and the single point with the worst residual is
thrown out. The process is repeated, tossing out the point
with the worst residual at each step, until only 10 points
remain. The final straight line is taken to be the actual
drift of the surface echo with respect to the carrier.
(6) An estimate of the noise power is made by averaging 64
frequency bins from 300 spectra on the side OPPOSITE the
surface echo and comparing the average with a system
temperature estimate provided by the DSN Monitor data.
The noise pedestal is removed and the remaining values are
scaled to units of watts.
(7) Five bins centered on the carrier are summed to obtain
the carrier power.
(8) Seven bins centered on the fitted straight line are
summed to obtain the echo power.
(9) The results are tabulated for each of the 300 spectra
and stored in the SRT file.
(10) The array of 300 512-point spectra is saved as the
SRI file.
(11) Fitting of the straight line to the echo trajectory is
not always successful. Column 25 in the header of the SRT
file is set to '0' when the fit is unsatisfactory. In most
cases, this results from a very weak surface echo; in a few
cases, the fitting algorithm simply fails.
Bistatic Radar Power Spectra are sums of 2929 individual
spectra (60 second averages). The spectra have 512 points
and cover 25000 Hz. The ground calibration procedure failed,
so a nominal system temperature of 30 K was assumed for each
channel and the spectra were scaled to have the equivalent
noise power density where there was no direct signal from the
spacecraft and no surface echo.
Data
====
Data are stored on CD-WO volumes approximately in order by the
time at which they were delivered for archiving. A CD volume
of reduced data was prepared approximately every 3-6 months
and forwarded to PDS.
Standard resolution temperature-pressure profiles are stored
in the TPS directory with file names of the form ydddhmmC.TPS
where y is the least significant digit of the year, ddd is
the three-digit day number, h is one-character which denotes
the hour, and mm is a two-character string denoting the
minute in which data acquisition began. h is 'A' if the
hour was 00, 'B' if the hour was 01, ... and 'X' if the hour
was 23. In most cases mm is the two-digit minute; but when
data were collected from two sources and the start time was
in the same minute, the second digit in mm was changed to a
letter in the second file name (minute 00 becomes 0A,
01 becomes 0B, etc.). C is a single character indicating
the version of the file, starting with 'A'.
Occultation summary files are stored in the OCS directory.
File names are of the form YMMymmCC.OCS, where Y is the
one-digit year of the first entry in the file, MM is the
two-digit month of the first entry, y is the one-digit year
of the last entry, and mm is the two-digit month of the last
entry. CC is a two-character string indicating the version
of the file.
ASCII spherical harmonic models are stored in the SHA directory
with file names of the form GTnnnnvv.SHA where
G denotes the generating institution
J for Jet Propulsion Laboratory
G for Goddard Space Flight Center
C for Centre National d'Etudes Spatiales
T denotes the type of data represented
G for gravity field
T for topography
M for magnetic field
nnnn is a 4-character modifier specified by the data producer
vv is a decimal version number, initialized to '01' and
SHA denotes that this is an ASCII file of spherical harmonic
coefficients. The distinction between 'nnnn' and 'vv' is not
enforced strictly, however; in some cases, it has been more
convenient to use all six characters to capture a model name
and/or number used by the data producer.
Binary spherical harmonic models are stored in the SHB
directory with file names of the form GTnnnnvv.SHB where
individual name components are as defined above except for the
SHB suffix.
Radio Science Digital Map products are stored in the IMG
directory with file names of the form GTnnnnnn.IMG where
G denotes the generating institution
J for Jet Propulsion Laboratory
G for Goddard Space Flight Center
C for Centre National d'Etudes Spatiales
S for Stanford University
T denotes the type of data represented
G for free air gravity field
O for geoid
B for Bouguer anomaly
I for isostatic anomaly
T for topography
M for magnetic field
nnnnnn is a 6-character modifier specified by the data
producer and IMG denotes that this is a PDS image object.
Line-of-sight acceleration profiles are stored in the LOS
directory with file names of the form MOnnnnnC.LOS where
nnnnn is the 5-digit orbit number and C is a character
indicating the version (starting from 'A').
Surface Reflection Antenna, Geometry, Image, and Table data
are stored in the SRA, SRG, SRI, and SRT directories,
respectively, with file names constructed using the same
procedure as for the TPS files except that file extensions
are SRA, SRG, SRI, and SRT.
Bistatic Radar Power Spectra are stored in the SPC directory
with file names BSR0135R.SPC and BSR0135L.SPC (there are
only two SPC files, and both are stored in volume MORS_1038).
Each data file is accompanied by a PDS label. If the name
of the data file is zzzzzzzz.ext, then the name of the label
file is zzzzzzzz.LBL.
Ancillary Data
==============
When radio occultation data are present on the volume, one
or more files with names of the form OCCLOGxx.TAB may be
included in the DOCUMENT directory. These files list
parameters for each radio occultation data acquisition
opportunity. PDS detached labels OCCLOGxx.LBL describe
the format and contents of the files.
Coordinate System
=================
MGS RST SDP files use a Mars centered body-fixed coordinate
system with positive east longitude.
Gravity models generally used the IAU 1991 [DAVIESETAL1992B]
or IAU 2000 [SEIDELMANNETAL2002] coordinate frame, depending
on when the model was constructed. See labels of specific
gravity products for details.
Software
========
None.
Media/Format
============
The archival data set was written on CD-WO media using the
Sun Ultra-5/Yamaha/GEAR CD authoring subsystem provided by
the MGS Project until June 2002. Volumes written later than
June 2002 and before the end of 2006 were written on a
Sun-Ultra5/PlexWriter/cdrtoaster system. Volumes written
in 2007 were written on a Sun-Ultra60/PlexWriter system.
The CD-WO volumes conform to ISO 9660 standards.
|
| DATA_SET_RELEASE_DATE |
2003-06-30T00:00:00.000Z
|
| START_TIME |
1997-09-12T12:00:00.000Z
|
| STOP_TIME |
2007-09-25T12:00:00.000Z
|
| MISSION_NAME |
MARS GLOBAL SURVEYOR
|
| MISSION_START_DATE |
1994-10-12T12:00:00.000Z
|
| MISSION_STOP_DATE |
2007-09-30T12:00:00.000Z
|
| TARGET_NAME |
MARS
|
| TARGET_TYPE |
PLANET
|
| INSTRUMENT_HOST_ID |
MGS
|
| INSTRUMENT_NAME |
RADIO SCIENCE SUBSYSTEM
|
| INSTRUMENT_ID |
RSS
|
| INSTRUMENT_TYPE |
RADIO SCIENCE
|
| NODE_NAME |
Planetary Plasma Interactions
|
| ARCHIVE_STATUS |
ARCHIVED
|
| CONFIDENCE_LEVEL_NOTE |
Overview
========
Data in this archive have been reduced as part of mission data
analysis activities of the MGS Radio Science Team. Products
of questionable validity have been flagged or omitted.
Review
======
This archival data set was reviewed by the MGS Radio Science
Team prior to submission to the Planetary Data System (PDS).
The MGS Science Data Validation Team (SDVT) monitored the
submissions.
Prior to creation of the final version of the archival data
set, key elements of the archive were distributed for
preliminary review. These included electronic versions of
example PDS labels, example data files, CATALOG files, and
Software Interface Specifications. These materials were
distributed to PDS personnel, the experiment investigator,
and others, as appropriate.
Data Coverage and Quality
=========================
MORS_1001
---------
T-p profiles included in this volume were derived from data
collected while the spacecraft was at nearly maximum
Earth-Mars range; the observations ended just a few days
before solar conjunction. See [HINSONETAL1999] for
discussion of results.
Dates: 1998/01/28 - 1998/04/10
Number of TPS Files: 88
Occultation Sense: Ingress only
Latitudes: 29N - 64S
Solar Zenith Angles: 85 - 106
Significant events during this period were:
YY/DDD Start Stop Comments
------ -------- -------- ----------------
98/024 19:15:36 19:32:15 First occultation recording
98/076 13:19:18 (ET) Close Phobos approach (380 km)
98/087 02:44:09 First SPO-1 periapsis gravity
98/088 01:51:00 02:15:00 First egress recording (LGA)
98/107 23:01:28 23:18:00 Last good ingress recording
98/118 15:52:00 16:33:00 Last occultation recording
Quality of data was affected by anomalous conditions during
data acquisition. Specifics are given in the OCCLOGA1.TAB
file in the DOCUMENT directory of MORS_1001; five general
types of problems dominated:
a) 2-6 dB lower carrier-to-noise level at Madrid antennas
throughout the occultation period (98/024-98/118), later
found to be from a weak oscillator in the front end of
the radio science receiver
b) 'Sawtooth' frequency residuals in approximately 10
percent of the data (all stations), later found to be
from an intermittent synchronization error in merging
two data streams at the DSN station
c) Amplitude baseline variations more than +/-0.1 dB
(various)
d) Spurs (occasional, no consistent pattern)
e) Unreliable local oscillator tuning (wrong controller
software) (Madrid antennas, 98/084-98/106)
Gravity models and maps included in this volume were generated
from Mariner 9 and Viking data. They do not contain any data
from the Mars Global Surveyor mission; they do, however, serve
as the baseline models from which the MGS models evolved.
Labels for each of the gravity products provide more
information on how the models were derived.
JGM50C01.SHA is the pre-MGS Mars gravity model produced at the
Jet Propulsion Laboratory under supervision of Bill Sjogren.
JGM50C01.IMG is the free-air gravity map corresponding to this
model. It is defined in IAU 1991 coordinates
[DAVIESETAL1992B].
GGM50A01.SHA is the pre-MGS Mars gravity model produced at
Goddard Space Flight Center under supervision of David Smith.
It is defined in IAU 1994 coordinates [DAVIESETAL1995].
GGM50A02.SHA is a slight variation on this model (a coordinate
transformation to IAU 1991 coordinates [DAVIESETAL1992B]) used
by David Hinson in reduction of radio occultation data
acquired during January-April 1998 and included in this
volume.
MORS_1002
---------
This volume contains gravity models and maps generated from
Mariner 9, Viking Orbiter, and MGS data collected through
mid-September 1998. The MGS data included tracking results
from Orbit Insertion subphases Aerobraking 1, Science Phasing
Orbit 1, and Science Phasing Orbit 2. Orbit periapsis passed
near Mars' north pole during the summer of 1998, so the data
are particularly good in defining the gravity field of the
north polar region.
GGM0890A.SHA is an ASCII file of coefficients for a 70x70
degree and order field produced at Goddard Space Flight
Center. GGM0890A.IMG is a gridded representation of the
field. Derivation of the model is described by a paper in
both PostScript and LaTeX formats in the DOCUMENT directory
(see DOCUMENT/AAS99147.LBL for details).
JGM75A01.SHA is an ASCII file of coefficients for a 75x75
degree and order field produced at the Jet Propulsion
Laboratory. JGM75A01.SHB is a binary file of covariances.
MORS_1003
---------
This volume contains gravity models and maps generated from
Viking Orbiter data and from MGS data collected through March
1999. The MGS data include tracking from Orbit Insertion
subphases Aerobraking 1, Science Phasing Orbit 1, Science
Phasing Orbit 2, the Gravity Calibration Orbit, and
approximately the first month of MGS Mapping operations,
while the high-gain antenna was still not deployed. Noise
produced by the control system after HGA deployment corrupted
the tracking data and several months were required before a
solution was found.
GGM0964A.SHA is an ASCII file of coefficients for a 70x70
degree and order field produced at Goddard Space Flight
Center. GGM0890A.IMG is a gridded representation of gravity
anomalies with respect to an evaluation of the Goddard model
to degree and order 50. Derivation of the model is
described by a paper in both PostScript and LaTeX formats in
the DOCUMENT directory (see DOCUMENT/AAS99328.LBL for
details). The Goddard group argues that the MGS data are of
sufficient quality that historic data (Mariner 9 and Viking
Orbiter) can be omitted. Their solution is based solely on
MGS data.
JGM75B01.SHA is an ASCII file of coefficients for a 75x75
degree and order field produced at the Jet Propulsion
Laboratory. JGM75B01.SHB is a binary file of coefficients
and covariances. JGD75B50.IMG is a gridded representation
of gravity anomalies with respect to an evaluation of the
JPL model to degree and order 50. The JPL solution
continues to include Viking Orbiter data.
The Goddard group has also provided a map of uncertainties
in their gravity anomalies; the JPL group has provided a
map of geoid height above a reference ellipsoid.
The BRO directory is new with this volume; it contains
PostScript representations of selected gravity results.
For a discussion of the major conclusions resulting from
study of the gravity field to this point, see [SMITHETAL1999].
MORS_1003 also contains 36 radio occultation profiles of
neutral atmosphere temperature and pressure derived from data
collected in late December 1998. These observations were
made while there was no telemetry modulation on the spacecraft
carrier, providing some of the highest signal-to-noise prior
to circularization of the orbit (February 1999). See
[HINSONETAL2001] for more information.
Dates: 1998/12/24 - 1998/12/31
Number of TPS Files: 36
Occultation Sense: Ingress only
Latitudes: 64N - 67N
Solar Zenith Angles: 78 - 81
MORS_1004
---------
This volume contains a gravity model and maps generated at
JPL from MGS tracking data collected through early November
1999. The MGS data included tracking results from the
following phases/subphases of the mission: Science Phasing
Orbit 1, Science Phasing Orbit 2, Gravity Calibration Orbit,
Fixed High-Gain Antenna Mapping, and the first seven months
of Mapping.
JGM75C01.SHA is an ASCII file of coefficients for a 75x75
degree and order field produced at the Jet Propulsion
Laboratory. JGM75C01.SHB is a binary file of coefficients
and covariances. JGD75C60.IMG is a gridded representation
of gravity anomalies with respect to an evaluation of the
JPL model to degree and order 60. JOD75C60.IMG is a
gridded representation of geoid height with respect to
a reference ellipsoid.
MORS_1004 also contains example files from the Surface
Reflection investigation. 9133H43A.SRG is a summary table
of observing geometry for an occultation starting
1999-133T07:43:00. 9133H43A.SRT is a tabulation of carrier
and surface echo signal characteristics. 9133H43A.SRI is
a two-dimensional array showing signal strength as a
function of both frequency and time around the occultation.
Surface echo was visible while the specular point moved
from about (69S, 91W) to about (68S, 83W).
MORS_1005
---------
MORS_1005 contains 97 temperature-pressure profiles from
radio occultations acquired during March 1999 while the
spacecraft was in Fixed-High Gain Antenna operations. The
analysis was carried out using the JPL MGS75C gravity model
and associated trajectory reconstructions (see MORS_1004).
Dates: 1999/03/07 - 1999/03/27
Number of TPS Files: 97
Occultation Sense: 48 ingress; 49 egress
Latitudes: 73N - 68N; 74S - 75S
Solar Zenith Angles: 76 - 78; 101 - 98
There are also four sets of three files from the surface
reflection investigation. The new files accompany a single
set of three files which appeared on MORS_1004. All sample
Mars surface at latitudes 68-69S and longitudes 80-105W.
MORS_1006
---------
MORS_1006 contains 440 temperature-pressure profiles from
radio occultations acquired during May and June 1999 after
the spacecraft recovered from the HGA azimuth anomaly and
resumed Mapping operations. The analysis was carried out
using the JPL MGS75C gravity model and associated trajectory
reconstructions (see MORS_1004).
Dates: 1999/05/06 - 1999/06/27
Orbit Numbers: 712 - 1356
Number of TPS Files: 440
Occultation Sense: Ingress only
Latitudes: 36N - 30S
Solar Zenith Angles: 98 - 119
This volume contains a gravity model and maps generated at JPL
from MGS tracking data collected through late March 2000. The
model also includes data from Mariner 9 and the two Viking
Orbiters.
JGM75D01.SHA is an ASCII file of coefficients for the 75x75
degree and order gravity field produced at JPL. JGM75D01.SHB
is a binary file of coefficients and covariances. JGD75D60.IMG
is a gridded representation of gravity anomalies with respect
to an evaluation of the JPL model to degree and order 60.
JOD75D60.IMG is a gridded representation of geoid height with
respect to a reference ellipsoid.
There are also 105 sets of three files from the surface
reflection investigation. The new files were based on data
collected during March 1999 and sample the surface at
latitudes 70-75 in both the northern (ingress) and southern
(egress) hemispheres.
MORS_1007
---------
This volume contains only Special Data Products (SPDPs).
Included are 32 electron density profiles derived from
ingress radio occultation data acquired 24-31 December
1998 (latitude approximately 65N). Profiles of the neutral
atmosphere appeared on MORS_1003.
There are also 696 sets of three files from the surface
reflection investigation. The new files were derived from
radio occultations acquired during April-May 1999 and sample
the surface at latitudes of approximately 15-65N (ingress)
and 60-70S (egress).
MORS_1008
---------
MORS_1008 contains 442 temperature-pressure profiles from
egress radio occultations acquired during May and June 1999
while the spacecraft conducted Mapping operations. The
analysis was carried out using the JPL MGS75C gravity model
and associated trajectory reconstructions (see MORS_1004).
This set of profiles completes the collection based on the
first occultation season in MGS Mapping; the next occultations
were obtained starting in December 1999.
Dates: 1999/05/06 - 1999/06/27
Orbit Numbers: 713 - 1348
Number of TPS Files: 442
Occultation Sense: Egress only
Latitudes: 70S - 67S
Solar Zenith Angles: 88 - 79
This volume contains the MGM0964C20 gravity model which was
developed at the Goddard Space Flight Center and which
provided a reference geoid used extensively by the MOLA
team in their data analysis. The model is archived on this
volume primarily for historical purposes. File GGM0964B.SHA
contains ASCII coefficients and uncertainties for the
spherical harmonic model.
Also on the volume is an 80x80 gravity model developed at
GSFC and based on MGS radio tracking data collected through
2000-02-29. No Viking or Mariner 9 data were used in the
solution. File GGM2BC80.SHA contains ASCII coefficients and
uncertainties for the spherical harmonic model. Gravity
anomaly is presented in gridded format in GGM2BA60.IMG at
1 degree resolution. GOM2BA60.IMG contains gridded geoid
values at 0.25 degree resolution. Also available are
three grids of error in the gravity anomaly based on
evaluation of the model using 60x60, 70x70, and 80x80
terms.
There are also 427 sets of three files from the surface
reflection investigation. The new files were based on
data collected during May-June 1999 and sample the surface
at latitudes 15S-15N (ingress) and 60-65S (egress). This
set of SRX files completes the collection based on the first
occultation season in MGS Mapping; the next surface
reflections were obtained starting in December 1999.
MORS_1009
---------
MORS_1009 contains the 75x75 MGS75E gravity model developed
at JPL and based on MGS radio tracking data collected
through 2000-09-29. Both Viking Orbiter and Mariner 9 data
were also included in the solution. File JGM75E01.SHA
contains ASCII coefficients and uncertainties for the
spherical harmonic model; JGM75E01.SHB is a binary file
containing both coefficients and covariances. Gravity
anomaly is presented as gridded data in JGD75E60.IMG;
JOD75E60.IMG contains gridded geoid height values. The
gridded values were obtained by evaluating the spherical
harmonic coefficients to degree and order 60.
MORS_1010
---------
MORS_1010 contains 800 atmospheric profiles from radio
occultations captured during late December 1999 through
early February 2000. This was the beginning of the second
MGS radio occultation season; the set ends when operations
began in 'Beta Supplement' -- a configuration that did not
allow routine collection of egress occultations.
Dates: 1999/12/16 - 2000/02/07
Orbit Numbers: 3458 - 4111
Number of TPS Files: 800
Occultation Sense: 389 ingress; 411 egress
Latitudes: 55N - 63N; 0S - 35S
Solar Zenith Angles: 112 - 92; 123 - 110
MORS_1010 also contains 43 profiles of electron density in
the Mars ionosphere. These were derived from occultations
captured during the first three weeks of MGS Mapping
(1999-03-09 through 1999-03-27). Profiles of the neutral
atmosphere appeared on MORS_1005.
MORS_1011
---------
MORS_1011 contains 577 atmospheric profiles from ingress
radio occultations captured during November-December 2000.
This period included 'Campaign F' in mid-December when
Earth passed through the plane of the MGS orbit and joint
observations were conducted with TES to compare the two
atmospheric probing techniques. MORS_1011 includes 147
profiles from Campaign F.
The above data were reprocessed and released a second time
on MORS_1016. Users should use the results on MORS_1016.
MORS_1011 also includes 134 electron density profiles
derived from the Campaign F data. These data were later
reprocessed; the new results were archived on MORS_1019.
MORS_1012
---------
MORS_1012 contains results from surface reflection analysis
of 725 radio occultations. These cover 19 December 1999
through 31 January 2000, inclusive. Both ingress and egress
occultations are included, but few of the egress occultations
produced detectable surface echoes.
MORS_1013
---------
MORS_1013 contains 826 temperature-pressure profiles derived
from ingress radio occultation measurements acquired during
August-October 2000.
The above data were later reprocessed and released a second
time on MORS_1015. Users should use the files on MORS_1015.
MORS_1013 also includes 525 sets of three files from the
surface reflection investigation based on data collected
during February-March 2000. Latitudes sampled include
approximately 32-36S and 48-49S (egress) and 63-68N (ingress).
Many more ingress occultations were captured during this
period because of HGA pointing limitations in Beta Supplement
mode.
MORS_1014
---------
MORS_1014 contains results from surface reflection analysis
of 793 radio occultations. These cover January through March
2001, inclusive. Both ingress and egress occultations are
included, but the number of egress occultations is very small
because of HGA pointing limitations during Beta Supplement
operations. Latitudes sampled include approximately 73S
(egress) and 72-86N (ingress).
MORS_1015
---------
MORS_1015 includes a new 85x85 degree and order solution for
the gravity field of Mars from the JPL Gravity Science Team
and a new 80x80 solution from the GSFC gravity group.
ASCII spherical harmonic coefficients for the JPL model are in
SHA/JGM85F01.SHA; binary coefficients and covariances are in
SHB/JGM85F01.SHB. Images of gravity anomalies and the geoid
are in the IMG directory (files JGD85F60.IMG and JOD85F60.IMG,
where each has been evaluated from degree 2 up to degree 60.
The 85F model was derived from Mariner 9, Viking 1/2, and MGS
data collected through 2001-08-14.
GSFC ASCII spherical harmonic coefficients are in the SHA
directory (file GGM1025A.SHA). Images of gravity anomalies
are in the IMG directory (files GGM1025A.IMG and GGM1025B.IMG,
where the first was evaluated up to degree 60 and the second
up to degree 66). A Postscript file showing gravity anomalies
is in BRO/GGM1025A.PS1. The MGM1025 model was derived solely
from MGS radio tracking data collected through 2001-07-21 and
from MOLA crossover analyses.
The EDS directory contains 220 ionospheric electron density
profiles derived from occultation data collected between
1999/126 and 1999/149. Latitudes ranged from 64S to 69S,
while solar zenith angle decreased from 87 to 78 degrees.
Profiles of the neutral atmosphere appear on MORS_1008.
The TPS directory holds 826 reprocessed atmospheric profiles
for ingress occultations between August (day 214) and October
(day 305) in 2000. The original profiles were released on
MORS_1013. The new profiles are more accurate than the
originals, which contained a small bias caused by motion of
the spacecraft high-gain antenna. The old files had names
of the form ydddHmmA.TPS; the new file names are ydddHmmB.TPS.
The OCS directory contains an Occultation Summary File
(008010AB.OCS) for the reprocessed TPS profiles.
Dates: 2000/08/01 - 2000/10/31
Orbit Numbers: 6254 - 7379
Number of TPS Files: 826
Occultation Sense: Ingress only
Latitudes: 67N - 62N
Solar Zenith Angles: 91 - 86
MORS_1016
---------
The TPS directory contains two sets of atmospheric occultation
profiles. First are 125 egress profiles from fixed high-gain
antenna observations scattered through Beta Supplement
operations.
Dates: 2000/05/20 - 2000/05/22
Orbit Numbers: 5370 - 5393
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 75S - 77S
Solar Zenith Angles: 94 - 95
Dates: 2000/08/08 - 2000/08/09
Orbit Numbers: 6346 - 6357
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 73S - 74S
Solar Zenith Angles: 86 - 87
Dates: 2000/09/08 - 2000/09/09
Orbit Numbers: 6726 - 6737
Number of TPS Files: 4
Occultation Sense: Egress only
Latitudes: 67S - 68S
Solar Zenith Angles: 86 - 87
Dates: 2000/10/13 - 2000/10/14
Orbit Numbers: 7154 - 7165
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 64S - 65S
Solar Zenith Angles: 89 - 90
Dates: 2000/11/17 - 2000/11/20
Orbit Numbers: 7582 - 7618
Number of TPS Files: 24
Occultation Sense: Egress only
Latitudes: 65S - 66S
Solar Zenith Angles: 94 - 95
Dates: 2000/12/18 - 2000/12/21
Orbit Numbers: 7961 - 7997
Number of TPS Files: 25
Occultation Sense: Egress only
Latitudes: 69S - 70S
Solar Zenith Angles: 99 - 100
Dates: 2001/01/10 - 2001/01/11
Orbit Numbers: 8243 - 8254
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 73S - 74S
Solar Zenith Angles: 102 - 103
Dates: 2001/04/05 - 2001/04/06
Orbit Numbers: 8243 - 8254
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 89S - 90S
Solar Zenith Angles: 105 - 106
Dates: 2001/05/13 - 2001/05/14
Orbit Numbers: 9747 - 9758
Number of TPS Files: 12
Occultation Sense: Egress only
Latitudes: 83S - 84S
Solar Zenith Angles: 96 - 98
Second are 843 reprocessed profiles from November 2000 through
January 2001. The November-December 2000 data were previously
released on MORS_1011; the January 2001 data were released
through a Stanford website but were not previously delivered
to PDS. Files 0325Q18B.TPS and 1029D33B.TPS had appeared in
the earlier releases (MORS_1011 and web site, respectively)
but were withdrawn from this release because of severe
degradation by antenna motion and generally poor data quality,
respectively.
Dates: 2000/11/01 - 2001/01/31
Orbit Numbers: 7380 - 8504
Number of TPS Files: 843
Occultation Sense: Ingress only
Latitudes: 63N - 78N
Solar Zenith Angles: 87 - 75
The OCS directory has two files. 005105AA.OCS summarizes
the newly released egress profiles from May 2000 through
May 2001. 011101AB.OCS summarizes the reprocessed profiles
from November 2000 through January 2001; it supersedes
011012AA.OCS on MORS_1011 though the earlier file did not
include the January 2001 data.
Also included in this volume are the first 687 Surface
Reflection Antenna (SRA) files. These cover 1999/127
through 1999/178 and may be used in conjunction with SRG,
SRI, and SRT files for the same occultations.
MORS_1017
---------
The TPS directory contains 433 ingress occultation profiles
derived from data collected in April-May 2000. These data
were reprocessed to improve the correction for high-gain
antenna motion during the experiment, so have file names of
the form ydddHmmB.TPS. The corresponding ydddHmmA.TPS files
were generated, but were never archived.
Dates: 2000/04/01 - 2000/05/31
Orbit Numbers: 4761 - 5504
Number of TPS Files: 433
Occultation Sense: Ingress only
Latitudes: 68N - 74N
Solar Zenith Angles: 87 - 90
The OCS directory includes a single file 004005AB.OCS,
which contains summary data from the 433 TPS files.
The SRA directory contains 693 surface reflection antenna
files covering 1999/354-2000/038.
MORS_1018
---------
The TPS directory contains 993 ingress occultation profiles
derived from data collected in February-June 2001. These
data have file names of the form ydddHmmA.TPS. Scattered
egress occultations from the same period are in MORS_1016.
Dates: 2001/02/01 - 2001/06/20
Orbit Numbers: 8505 - 10212
Number of TPS Files: 993
Occultation Sense: Ingress only
Latitudes: 85N - 51N
Solar Zenith Angles: 71 - 97
The OCS directory includes a single file 102106AA.OCS,
which contains summary data from the 993 TPS files.
The SRA directory contains 599 surface reflection antenna
files covering 2001/001 - 2001/090.
MORS_1019
---------
The TPS directory contains 360 occultation profiles derived
from data collected in June and July 2000. These data have
file names of the form ydddHmmA.TPS.
Dates: 2001/06/21 - 2001/07/15
Orbit Numbers: 10221-10517
Number of TPS Files: 181
Occultation Sense: Ingress
Latitudes: 51N - 9N
Solar Zenith Angles: 97 - 114
Dates: 2001/06/21 - 2001/07/16
Orbit Numbers: 10221-10534
Number of TPS Files: 179
Occultation Sense: Egress
Latitudes: 70S - 47S
Solar Zenith Angles: 87 - 95
The OCS directory includes a single file 106107AB.OCS,
which contains summary data on the TPS files.
The EDS directory includes 134 reprocessed electron density
files from 9-21 December 2000; these have file names of the
form ydddHmmB.EDS and replace results originally released
on MORS_1011. The reprocessing included improved correction
for high-gain antenna motion, which may have left artifacts
in the earlier profiles. There are also 314 new electron
density files covering 22 December 2000 to 31 January 2001
with names ydddHmmA.EDS.
The SHA directory includes ASCII coefficients and uncertainties
for the JPL 85x85 MGS85H2 spherical harmonic model of the Mars
gravity field. The model was derived from MGS, 2001 Mars
Odyssey, Mars Pathfinder, and Viking 1 Lander data. No Viking
Orbiter or Mariner 9 data are included. The model is
referenced to a Mars fixed frame similar to the Mars Pathfinder
orientation model except that the prime meridian has been made
consistent with the IAU 2000 coordinate frame.
MORS_1020
---------
The TPS directory contains 742 occultation profiles derived
from data collected in February 2000 and March-May 2002. The
data from 2000 were delayed because of problems in the
reconstructed spacecraft orbits. The TPS data have file names
of the form ydddHmmA.TPS.
Dates: 2000/02/08 - 2000/02/29
Orbit Numbers: 4112 - 4380
Number of TPS Files: 170
Occultation Sense: Ingress
Latitudes: 63 - 64 N
Solar Zenith Angles: 92 - 89
Dates: 2002/03/14 - 2002/05/17
Orbit Numbers: 13470 - 14264
Number of TPS Files: 572
Occultation Sense: Ingress
Latitudes: 66 -63 N
Solar Zenith Angles: 88 - 91
The OCS directory includes two files (002002AA.OCS and
203205AA.OCS) which contain summary data on the TPS files.
MORS_1021
---------
The TPS directory contains 1259 occultation profiles derived
from data collected in March 2000 and from 13 December 2001
through 13 March 2002. The data from 2000 were delayed
because of problems in the reconstructed spacecraft orbits.
The TPS data have file names of the form ydddHmmA.TPS. The
summary file is in the OCS directory.
Dates: 2000/03/01 - 2000/03/31
Orbit Numbers: 4381 - 4760
Number of TPS Files: 214 9
Occultation Sense: Ingress Egress
Latitudes: 64 - 68 N 47 - 48 S
Solar Zenith Angles: 89 - 88 106 - 105
Summary File: 003003AA.OCS
Dates: 2001/12/13 - 2002/03/13
Orbit Numbers: 12368 - 13470
Number of TPS Files: 563
Occultation Sense: Egress
Latitudes: 11 N - 45 S
Solar Zenith Angles: 132 - 114
Summary File: 112203AA.OCS
Dates: 2002/01/08 - 2002/03/13
Orbit Numbers: 12678 - 13469
Number of TPS Files: 473
Occultation Sense: Ingress
Latitudes: 62 - 66 N
Solar Zenith Angles: 96 - 88
Summary File: 201203AA.OCS
The SHA directory contains ASCII coefficients for a 90x90
gravity model (GGM1041C.SHA) developed by the group at
Goddard Space Flight Center. This model is based on MGS
data collected through 27 May 2002. The IMG directory
contains maps showing gravity anomalies and the geoid
evaluated from the first 60, 66, and 72 terms of the 90x90
model.
MORS_1022
---------
The TPS directory contains 536 occultation profiles derived
from data collected from May to July 2002, immediately prior
to solar conjunction when signal-to-noise is lowest. All
occultations were ingress occultations. The TPS data
have file names of the form ydddHmmA.TPS. The summary file
is in the OCS directory.
Dates: 2002/05/18 - 2002/07/15
Orbit Numbers: 14265 - 14978
Occultation Sense: Ingress Egress
Number of TPS Files: 536 0
Latitudes: 55 - 63 N N/A
Solar Zenith Angles: 90 - 92 deg N/A
Summary File: 205207AA.OCS
MORS_1023
---------
The TPS directory contains 523 occultation profiles derived
from data collected in September and October 2002, immediately
after solar conjunction when signal-to-noise is lowest. All
occultations were ingress occultations. The TPS data
have file names of the form ydddHmmA.TPS. The summary file
is in the OCS directory.
Dates: 2002/09/08 - 2002/10/31
Orbit Numbers: 15648 - 16307
Occultation Sense: Ingress Egress
Number of TPS Files: 523 0
Latitudes: 53 - 60 N N/A
Solar Zenith Angles: 83 - 89 deg N/A
Summary File: 209210AA.OCS
The EDS directory contains 284 profiles of electron density
from data collected in November and December 2000. All of
these were ingress ionospheric occultations. The EDS data
have file names of the form ydddHmmA.EDS.
Dates: 2000/11/04 - 2000/12/08
Orbit Numbers: 7380 - 7844
Occultation Sense: Ingress Egress
Number of Files: 284 0
Latitudes: 63 - 68 N N/A
Solar Zenith Angles: 82 - 87 deg N/A
MORS_1024
---------
The TPS directory contains 1225 occultation profiles derived
from data collected between November 2002 and March 2003, as
Earth-Mars geometry moved from post-conjunction to near-
opposition. All occultations were ingress occultations. The
TPS data have file names of the form ydddHmmA.TPS. Two
summary files are in the OCS directory.
Dates: 2002/11/01 - 2003/03/21
Orbit Numbers: 16308 - 18030
Occultation Sense: Ingress
Number of TPS Files: 1225
Latitudes: 60N to 83 N
Solar Zenith Angles: 83 to 70
Summary Files: 211212AA.OCS (Nov-Dec 2002)
301303AA.OCS (Jan-Mar 2003)
The EDS directory includes 840 electron density profiles
from 1 February to 6 June 2001; these have file names of the
form ydddHmmB.EDS. All are ingress occultations with
solar zenith angles between 71 and 87 degrees.
The SHA directory includes ASCII coefficients and uncertainties
for the JPL 85x85 MGS85F2 spherical harmonic model of the Mars
gravity field. The model has been adopted by several flight
projects including Mars Reconnaissance Orbiter and Mars
Express. The model is referenced to a Mars fixed frame similar
to the Mars Pathfinder orientation model except that the prime
meridian has been made consistent with the IAU 2000 coordinate
frame. Also included is the JPL 95x95 model MGS95I, a more
recent and larger model.
MORS_1025
---------
The TPS directory contains 697 occultation profiles derived
from data collected between March and June 2003, as
Earth-Mars geometry moved from post-conjunction to near-
opposition. All occultations were ingress occultations. The
TPS data have file names of the form ydddHmmA.TPS. One
summary file is in the OCS directory.
Dates: 2003/03/22 - 2003/06/10
Orbit Numbers: 18039 - 19020
Occultation Sense: Ingress
Number of TPS Files: 697
Latitudes: 81 N to 69N
Solar Zenith Angles: 70 - 81
Summary Files: 303306AA.OCS (Mar-Jun 2003)
MORS_1026
---------
The TPS directory contains 640 occultation profiles derived
from data collected between June and September 2003, as
Earth-Mars geometry moved through opposition. All
occultations were ingress occultations. The TPS data have
file names of the form ydddHmmA.TPS. One summary file is
in the OCS directory.
Dates: 2003/06/18 - 2003/09/10
Orbit Numbers: 19114 - 20149
Occultation Sense: Ingress
Number of TPS Files: 640
Latitudes: 65 N to 70N
Solar Zenith Angles: 82 - 99
Summary File: 306309AA.OCS (Jun-Sep 2003)
MORS_1027
---------
The TPS directory contains 84 egress occultation profiles
derived from data collected between September 2002 and
August 2003, as Earth-Mars geometry moved toward opposition.
All occultations were collected as part of special egress
campaigns. The TPS data have file names of the form
ydddHmmA.TPS. One summary file is in the OCS directory.
Dates: 2002/09/30 - 2003/08/18
Orbit Numbers: 15924 - 19857
Occultation Sense: Egress
Number of TPS Files: 84
Latitudes: 62 S to 90 S
Solar Zenith Angles: 83 - 105
Summary File: 209308AA.OCS
The EDS directory contains 526 ingress electron density
profiles collected between November and December 2002.
File names have the form ydddHmmA.EDS.
Dates: 2002/11/01 - 2002/12/31
Orbit Numbers: 16308 - 17051
Occultation Sense: Ingress
Number of EDS Files: 526
Latitudes: 60 - 74 N
Solar Zenith Angles: 84 to 76
Summary File: none
MORS_1028
---------
The TPS directory contains 405 occultation profiles derived
from data collected between September and October 2003
as Earth-Mars geometry moved away from opposition. The TPS
file names have the form ydddHmmA.TPS. One summary file is
in the OCS directory.
Dates: 2003/09/11 - 2003/09/11 -
2003/09/28 2003/10/18
Orbit Numbers: 20150 - 20367 20151 - 20615
Occultation Sense: Ingress Egress
Number of TPS Files: 172 233
Latitudes: 60 - 66 N 1 - 45 S
Solar Zenith Angles: 105 - 98 92 - 124
Summary File: 309310AA.OCS 309310AA.OCS
The EDS directory contains 650 ingress electron density
profiles collected between January and March 2003.
File names have the form ydddHmmA.EDS.
Dates: 2003/01/01 - 2003/03/21
Orbit Numbers: 17057 - 18030
Occultation Sense: Ingress
Number of TPS Files: 650
Latitudes: 73 - 84 N
Solar Zenith Angles: 76 - 71
Summary File: none
MORS_1029
---------
The TPS directory contains 436 occultation profiles derived
from data collected between November 2003 and January 2004
as Earth-Mars geometry moved away from opposition. The TPS
file names have the form ydddHmmA.TPS. One summary file is
in the OCS directory.
Dates: 2003/11/16 - 2004/01/19
Orbit Numbers: 20958 - 21752
Occultation Sense: Egress
Number of TPS Files: 436
Latitudes: 11 N to 11 S
Solar Zenith Angles: 130 -132
Summary File: 311401AA.OCS
The EDS directory contains 630 ingress electron density
profiles collected between March and June 2004. File names
have the form ydddHmmA.EDS.
Dates: 2003/03/22 - 2003/06/04
Orbit Numbers: 18039 - 18948
Occultation Sense: Ingress
Number of EDS Files: 630
Latitudes: 81 - 69 N
Solar Zenith Angles: 71-80
Summary File: none
MORS_1030
---------
The TPS directory contains 1111 occultation profiles derived
from data collected between 1 March and 24 May as Mars moved
toward solar conjunction. Both ingress and egress
occultations are included, at virtually a constant 14 degree
angle from grazing. The TPS file names have the form
ydddHmmA.TPS. One summary file is in the OCS directory.
Dates: 2004/03/01 - 2004/05/24
Orbit Numbers: 22255 - 23292
Occultation Sense: Egress (691); Ingress (420)
Number of TPS Files: 1111
Latitudes: -26 to -61 (egr); 45 to 37 (ing)
Solar Zenith Angles: 125 to 109 (egr); 98 to 100 (ing)
Summary File: 403405AA.OCS
The EDS directory contains 76 ingress electron density
profiles collected between 22 June and 2 July 2003, about two
months before opposition. File names have the form
ydddHmmA.EDS.
Dates: 2003/06/22 - 2003/07/02
Orbit Numbers: 19163 - 19289
Occultation Sense: Ingress
Number of EDS Files: 76
Latitudes: 68 N
Solar Zenith Angles: 83 - 85
Summary File: none
MORS_1031
---------
The TPS directory contains 819 occultation profiles. Data
collected after 21 July were contaminated by anomalous HGA
motion and solar noise; conjunction was in mid-September.
Both ingress and egress occultations are included. TPS file
names have the form ydddHmmA.TPS. One summary file is in the
OCS directory.
Dates: 2004/05/25 - 2004/07/21
Orbit Numbers: 23293 - 24002
Occultation Sense: Egress (286); Ingress (533)
Number of TPS Files: 819
Latitudes: -72 to -69 (egr); 36 to 34 (ing)
Solar Zenith Angles: 100 to 92
Summary File: 405407AA.OCS
MORS_1032
---------
The TPS directory contains 696 occultation profiles. Early
data were noisy because of the solar conjunction in September.
These are mostly ingress occultations; a handful of egress
occultations were captured in two special campaigns. TPS file
names have the form ydddHmmA.TPS. One summary file is in the
OCS directory.
Dates: 2004/10/10 - 2004/12/22
Orbit Numbers: 24982 - 25878
Occultation Sense: Egress (15); Ingress (681)
Number of TPS Files: 696
Latitudes: -66 and -76 (egr); 48 - 68 (ing)
Solar Zenith Angles: 91 and 96 (egr); 87 to 76 (ing)
Summary File: 410412AA.OCS
MORS_1033
---------
The TPS directory contains 898 occultation profiles. Data
quality improved as the ray path moved away from the Sun
(solar superior conjunction in September 2004) and Earth-Mars
distance decreased. These are mostly ingress occultations; a
handful of egress occultations were captured in a special
campaign. TPS file names have the form ydddHmmA.TPS. One
summary file is in the OCS directory.
Dates: 2004/12/26 - 2005/04/01
Orbit Numbers: 25923 - 27096
Occultation Sense: Egress (9); Ingress (889)
Number of TPS Files: 898
Latitudes: -78 to -79 (egr); 69 to 79 (ing)
Solar Zenith Angles: 100 (egr); 72 to 76 (ing)
Summary File: 412504AA.OCS
The SHA directory includes ASCII coefficients and uncertainties
for the JPL 95x95 MGS95J spherical harmonic model of the Mars
gravity field. The model is referenced to a Mars fixed frame
similar to the Mars Pathfinder orientation model except that
the prime meridian has been made consistent with the IAU 2000
coordinate frame. The model is based on radio tracking data
from MGS, 2001 Mars Odyssey, Pathfinder, and Viking Lander 1;
data from the Viking Orbiters and Mariner 9 were omitted
because they did not seem to improve the solution.
MORS_1034
---------
The TPS directory contains 1568 occultation profiles. Data
quality improved as the ray path moved away from the Sun
(solar superior conjunction in September 2004) and Earth-Mars
distance decreased. These are mostly ingress occultations; a
handful of egress occultations were captured in special
campaigns. TPS file names have the form ydddHmmA.TPS. Two
summary files are in the OCS directory.
Dates: 2005/04/01 - 2005/08/26
Orbit Numbers: 27099 - 28902
Occultation Sense: Egress (14); Ingress (1554)
Number of TPS Files: 1568
Latitudes: -69, -64 (egr); 65 - 76 (ing)
Solar Zenith Angles: 99, 96 (egr); 75 - 106 (ing)
Summary Files: 504506AA.OCS, 507508AA.OCS
MORS_1035
---------
The TPS directory contains 1011 occultation profiles, about
equally divided between ingress and egress. The dates were
September to mid-November 2005, bracketing opposition.
TPS file names have the form ydddHmmA.TPS. The summary file
is 509511AA.OCS in the OCS directory.
Dates: 2005/09/09 to 2005/11/10
Orbit Numbers: 29066 - 29836
Occultation Sense: Egress (567); Ingress (444)
Latitudes: 78-67 S (egr); 79-71 N (ing)
Solar Zenith Angles: 80-92 (egr); 106-89 (ing)
The EDS directory contains 947 electron density profiles
for the ionosphere from ingress occultations collected
between November 2004 (shortly after solar conjunction) to
mid-March 2005. EDS file names are of the form ydddHmmA.EDS.
Dates: 2004/11/23 to 2005/03/10
Orbit Numbers: 25523 - 26839
Occultation Sense: Ingress (947)
Latitudes: 62N to 80N, then back to 76N
Solar Zenith Angles: 81 to 73
MORS_1036
---------
The TPS directory contains 997 occultation profiles, about
equally divided between ingress and egress. The dates were
mid-November through December 2005, after opposition.
TPS file names have the form ydddHmmA.TPS. The summary file
is 511512AA.OCS in the OCS directory.
Dates: 2005/11/11 to 2005/12/31
Orbit Numbers: 29836 - 30458
Occultation Sense: Egress (490); Ingress (507)
Latitudes: 67-34 S (egr); 71-63 N (ing)
Solar Zenith Angles: 92-122 (egr); 87-89 (ing)
The EDS directory contains 904 electron density profiles
for the ionosphere from ingress occultations collected
between mid-March 2005 and mid-June 2005. EDS file names
are of the form ydddHmmA.EDS.
Dates: 2005/03/11 to 2005/06/09
Orbit Numbers: 26840 - 27952
Occultation Sense: Ingress (904)
Latitudes: 76N to 65N
Solar Zenith Angles: 74 to 89 deg
MORS_1037
---------
The TPS directory contains 690 occultation profiles in two
groups (January-February and May-June 2006), about equally
divided between ingress and egress. TPS file names have the
form GdddHmmA.TPS, where 'G' denotes 2006, a convention
adopted to avoid confusion with '6' which denotes 1996 in
some MGS file types. The summary files are G01G02AA.OCS
and G05G06AA.OCS in the OCS directory.
Dates: 2006/01/01 to 2006/02/19
Orbit Numbers: 30461 - 31068
Occultation Sense: Egress (206); Ingress (103)
Latitudes: 31-23 S (egr); 62-60 N (ing)
Solar Zenith Angles: 124-129 (egr); 88-91 (ing)
Dates: 2006/05/10 to 2006/06/30
Orbit Numbers: 32041 - 32673
Occultation Sense: Egress (248); Ingress (133)
Latitudes: 56-70 S (egr); 13-18 N (ing)
Solar Zenith Angles: 115-107 (egr); 103-97 (egr)
There are no data between 2006/02/19 and 2006/05/10 because
the observing geometry gave almost grazing occultations.
Although the raypath reached the surface, the cut through the
atmosphere was more horizontal than vertical and reliable
profiles could not be derived.
MORS_1038
---------
The TPS directory contains 1423 occultation profiles, about
equally divided between ingress and egress. The dates were
early July through mid-September 2006, approaching solar
conjunction. TPS file names have the form GdddHmmA.TPS,
where 'G' denotes 2006, a convention adopted to avoid
confusion with '6' which denotes 1996 in some MGS file types.
The summary file is G07G09AA.OCS in the OCS directory.
Dates: 2006/07/01 to 2006/09/19
Orbit Numbers: 32673 - 33664
Occultation Sense: Egress (714); Ingress (709)
Latitudes: 70-63 S (egr); 18-36 N (ing)
Solar Zenith Angles: 97-88 (egr); 108-95 (ing)
The SPC directory has one pair of files containing bistatic
radar power spectra from an experiment conducted on
2000-05-14. Each file is a table holding spectra with either
right-circular or left-circular polarization (RCP or LCP
respectively). There are nine spectra in each file; each is
an average over 60 seconds. The ground track in this
experiment went very close to the target landing site of the
failed MPL/DS2 spacecraft [SIMPSON&TYLER2001].
Limitations
===========
The limitations in this data set follow from the quality of
the execution, which is described above under Data Coverage
and Quality.
|
| CITATION_DESCRIPTION |
Tyler, G.L., G. Balmino,
D.P. Hinson, W.L. Sjogren,
D.E. Smith, R. Woo,
J.W. Armstrong, F.M. Flasar,
R.A. Simpson, S. Asmar,
A. Anabtawi, and P. Priest,
MGS RST Science Data Products,
MGS-M-RSS-5-SDP-V1.0,
NASA Planetary Data System,
2007.
|
| ABSTRACT_TEXT |
This data set contains archival results from radio science
investigations conducted during the Mars Global Surveyor (MGS)
mission. Radio measurements were made using the MGS spacecraft
and Earth-based stations of the NASA Deep Space Network (DSN).
The data set includes high-resolution spherical harmonic models
of Mars' gravity field generated by groups at the Jet Propulsion
Laboratory and Goddard Space Flight Center, covariance matrices
for some models, and maps for some models; these results were
derived from raw radio tracking data. Also included are profiles
of atmospheric temperature and pressure and ionospheric electron
density, derived from phase measurements collected during radio
occultations. The data set also includes analyses of transient
surface echoes observed close to occultations during the first
few years of MGS operations and a single set of power spectra
acquired during a quasi-specular bistatic radar experiment in
2000. The atmospheric and surface investigations were conducted
by Radio Science Team members at Stanford University. The data
set also includes 93 line-of-sight acceleration profiles derived
at JPL from radio tracking data collected near periapsis while
Mars Global Surveyor was in its Science Phasing Orbit and below
its nominal Mapping altitude of 400 km. The data were delivered
to PDS in approximately chronological order at the rate of one
CD-WO volume (typically 100 MB) every three months.
|
| PRODUCER_FULL_NAME |
RICHARD A. SIMPSON
G. LEONARD TYLER
|
| SEARCH/ACCESS DATA |
Geosciences Web Services
Planetary Plasma Interactions Website
Atmospheres Online Archives
Geosciences Online Archives
|
|
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