urn:nasa:pds:mgs-rss:data-eds:5014n11a 1.0 1.22.0.0 Product_Observational 2025 MGS RSS This file contains Mars Global Surveyor (MGS) ionospheric electron density profiles (EDS) derived from the Mars radio occulation data. These data cover 2005-01-14T13:11:00Z to 2005-01-14T13:21:00Z. David Hinson 1 Stanford University https://ror.org/00f54p054 2025-02-10 1.0 This product, 5014N11A.EDS, was originally released as part of the PDS3 MGS-M-RSS-5-EDS-V1.0 and MGS-M-RSS-5-EDS-V1.0 data set. The metadata have been migrated to PDS4. The data themselves are unchanged. 2005-01-14T13:11:00Z 2005-01-14T13:21:00Z Science Derived MGS Ionospheric Electron Density Profiles Ionosphere Particles Electrons Mars Global Surveyor Mission urn:nasa:pds:context:investigation:mission.mars_global_surveyor data_to_investigation Mars Global Surveyor Host urn:nasa:pds:context:instrument_host:spacecraft.mgs is_instrument_host Radio Science Subsystem (RSS) Instrument urn:nasa:pds:context:instrument:mgs.rss is_instrument Mars Planet urn:nasa:pds:context:target:planet.mars data_to_target Electrons Density Profile urn:nasa:pds:mgs-rss:data-sha:jgm75c01::1.0 data_to_derived_product 10.1029/1999JE001069 J.D. Twicken, and G.L. Tyler, Initial Results from Radio Occultation Measurements with Mars Global Surveyor, Journal of Geophysical Research, 104, 26997-27012, 1999. 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). 10.1029/2001GL012884 Bougher, S.W., Engel, S., Hinson, D., Forbes, J., Mars Global Surveyor radio science electron density profiles: Neutral atmosphere implications, Geophysical Research Letters, 28(16), pp. 3091-3094. MGS-M-RSS-5-EDS-V1.0:5014N11A.EDS:5014N11A.EDS data_to_derived_source_product 10.17189/1519756 PDS Planetary Plasma Interactions Node This is the first version converted to PDS4. The DOI references the source PDS3 data set. MGS-M-RSS-5-EDS-V1.0:5014N11A.EDS:5014N11A.EDS data_to_derived_source_product 10.17189/1519757 PDS Planetary Plasma Interactions Node This is the first version converted to PDS4. The DOI references the source PDS3 data set. 5014N11A.EDS 2008-05-09T12:38:44 11088 f342bbfe046efd40be25c4d6966ff9b6 File names have the form ydddHmmA.EDS. Where y is the year, ddd is the day of year, h, is a 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 and A is the version. MGS Derived Electron Density Profiles 2005-01-14T13:11 - 2005-01-14T13:21 Ancillary Data 0 PDS DSV 1 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). 1 Carriage-Return Line-Feed Comma 25 0 280 Start Time 1 ASCII_Date_Time_YMD 23 The Earth Receive Time at which the first radio occultation data sample was acquired. Stop Time 2 ASCII_Date_Time_YMD 23 The Earth Receive Time at which the last radio occultation data sample was acquired. Occultation Time 3 ASCII_Date_Time_YMD 23 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. Orbit Number 4 ASCII_Integer 5 %5d Orbit number from which the data were acquired; set to zero if not known. DSN Antenna Number 5 ASCII_Integer 2 %2d Number of the DSN antenna used to collect the data (e.g., 14, 43, 65, ...). Ray Path Direction 6 ASCII_Real 6 %6.1f deg 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. Angle From Diametric 7 ASCII_Real 6 %6.1f deg 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. Latitude Of Profile 8 ASCII_Real 7 %7.3f deg Areocentric (north) latitude where the experiment sounded the ionosphere at 130 km altitude. Sigma Latitude 9 ASCII_Real 6 %6.3f deg One standard deviation uncertainty in LATITUDE OF PROFILE. This value also serves as an estimate of the uncertainty in LATITUDE in the header. Set to -9.999 if not known. -9.999 Longitude Of Profile 10 ASCII_Real 8 %8.3f deg Areocentric east longitude where the experiment sounded the ionosphere at 130 km altitude. Sigma Longitude 11 ASCII_Real 6 %6.3f deg One standard deviation uncertainty in Longitude of Profile. This value also serves as an estimate of the uncertainty in longitude in the header. Set to -9.999 if not known. -9.999 Sub-Solar Latitude 12 ASCII_Real 6 %6.2f deg Areocentric (north) latitude of the sun at occulation time. Sub-Solar Longitude 13 ASCII_Real 7 %7.2f deg Areocentric east longitude of the sun in body fixed coordinates at occultation time. Solar Longitude 14 ASCII_Real 6 %6.2f deg 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. Spacecraft To Limb Distance 15 ASCII_Real 9 %9.3e m 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. Spacecraft To DSN Distance 16 ASCII_Real 9 %9.3e m Distance from spacecraft to DSN receiving antenna at time when experiment was sounding the ionosphere at 130 km altitude. Mars To Sun Distance 17 ASCII_Real 9 %9.3e m Distance from Mars to Sun at occultation time. Local True Solar Time 18 ASCII_Real 6 %6.3f hr 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. Solar Zenith Angle 19 ASCII_Real 6 %6.2f deg Angle between the direction to Sun and local vertical direction on Mars at time and location of the occultation measurement. Sun-Earth-Spacecraft Angle 20 ASCII_Real 5 %5.1f deg Approximate angle between Sun and spacecraft as viewed from Earth during experiment. DSN Elevation Angle 21 ASCII_Real 5 %5.1f deg Approximate angle between direction to spacecraft and local horizon at DSN receiving antenna during experiment. Gravity Field Model 22 ASCII_String 12 %12s File name of gravity field spherical harmonic model used in defining reference areoid. Located in: urn:nasa:pds:mgs-rss:data-sha PCK File Name 23 ASCII_String 12 %12s 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). Trajectory File Name 24 ASCII_String 12 %12s File name of the spacecraft and planetary ephermeris file used in this retrieval and calculation (name of the file as stored in the MGS RST data system). Spacecraft Attitude File Name 25 ASCII_String 15 %15s 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. MGS Derived Electron Density Profiles 2005-01-14T13:11 - 2005-01-14T13:21 Data 280 PDS DSV 1 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. 193 Carriage-Return Line-Feed Comma 6 0 56 Radius 1 ASCII_Real 8 %8.0f m Measurement radius. Altitude 2 ASCII_Real 7 %7.0f m Altitude of measurement above reference areoid. The reference areoid is the equipotential surface whose mean equatorial radius is 3,396,000 m. Latitude 3 ASCII_Real 7 %7.3f deg Areocentric (north) latitude of measurement. Longitude 4 ASCII_Real 8 %8.3f deg Areocentric (east) longitude of measurement in body fixed coordinates. Electron Number Density 5 ASCII_Real 11 %11.4e 1/m**3 One standard deviation uncertainty in Electron Number Density. Sigma Electron Number Density 6 ASCII_Real 8 %8.2e 1/m**3