2024-03-29T12:04:28.668Zhttps://cmr.earthdata.nasa.gov/opensearch/collections.atomCMRechodev@echo.nasa.govECHO dataset metadataSearch parameters: satellite => CHAMP boundingBox => startTime => endTime => 251011https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586630-SCIOPSCMRechodev@echo.nasa.govCHAMP Vector Magnetometer in ECEF (NEC) SystemCHAMP, Magnetic and Electric FieldC1214586630-SCIOPS2000-07-26T00:00:00.000Z/CHAMP Vector Magnetometer in ECEF (NEC) SystemCH-ME-2-FGM-NEC1.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse1.43https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586613-SCIOPSCMRechodev@echo.nasa.govCHAMP Vector Magnetometer in local FGM Sensor SystemCHAMP, Magnetic and Electric FieldC1214586613-SCIOPS2000-07-25T00:00:00.000Z/CHAMP Vector Magnetometer in local FGM Sensor SystemCH-ME-2-FGM-FGM1.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse1.43https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214610989-SCIOPSCMRechodev@echo.nasa.govGenesis GPS Occultation Observations Level 1AThe Genesis GPS Occultation Observations Level 1A data set consists of
LEO-GPS (low-earth-orbiter satellites and Global Positioning System
satellites) radio occultation (limb sounding) atmospheric phase delay
and amplitude data for use in computing atmospheric refractivity,
temperature, pressure, and water vapor profiles. LEOs collecting
occultation data include GFZ's CHAMP (CHallenging Minisatellite
Payload satellite) and CONAE's SAC-C. Data are available at the two
GPS frequencies, 1.2 and 1.6 GHz, the latter at a time resolution of
0.01 or 0.02 seconds. These are the Level 1A products of this radio
occultation data set.
The full set of products available include
* Level 0: Raw GPS data
* GPS data for orbit determination in RINEX format
* Orbit products
* Level 1A: Atmospheric phase delay and signal amplitude
* Level 1B: Atmospheric doppler shift and bending
* Level 2: Atmospheric refractivity, temperature, pressure, water vapor
pressure profiles, and comparisons to weather analysis and
radiosondes.
CHAMP and SAC-C each carry a JPL Blackjack GPS receiver and a
rearward-facing antenna to record the signals of GPS satellites
setting behind the Earth's limb as the signal passes through the
atmosphere. (SAC-C also carries a forward-facing antenna, currently
inactive.) Typically over 200 of these "occultations" occur per day
per LEO with fairly uniform global distribution. By measuring the
precise phase delay experienced by the GPS signals, and using precise
clock-offset and orbit information, the atmospheric component of the
phase delay can be extracted. Assuming local spherical symmetry about
the tangent point, inversion of the atmospheric phase delay phase
measurements during an occultation yields atmospheric refractivity
profiles, which can be converted to temperature and pressure profiles
between 60 km and the middle troposphere, and, with independent
knowledge of temperature, into water vapor density in the middle and
lower troposphere.
Valuable properties of radio occultation measurements of atmospheric
profiles include:
* Self-calibrating, making them ideal for climate detection.
* Sub-kilometer vertical resolution.
* Sub-Kelvin temperature accuracy below 45 km.
* All-weather operation
* Independent height and pressure data allowing computation of
geopotential heights and derived wind fields
* Concurrent global coverage with a small constellation
Comparison of CHAMP and SAC-C to National Center for Environmental
Prediction (NCEP) and the European Center for Medium-range Weather
Forecast (ECMWF) analyses show that GPS occultation temperature
profiles are consistent with the models to better than 0.5 K in the
mean, and better than 1.5 K in standard deviation.
Geometric optics inversion techniques primarily use the phase delay,
but physical optics inversion can also make precise use of signal
amplitude variation to account for diffraction effects. Each Level 1A
data file contains atmospheric phase delay and amplitude data from a
single occultation at a rate of 50 or 100 samples/sec at the 1.6 GHz
frequency. 1.2 GHz data is also included, but may be noisier and at a
lower sample rate.C1214610989-SCIOPS2001-02-11T00:00:00.000Z/Genesis GPS Occultation Observations Level 1AJPL_Genesis_L1ANot providedSCIOPSNASA/JPL/GENESISNASA/JPL/GENESISCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse0.78000005org.geoss.geoss_data-coretruehttps://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214611007-SCIOPSCMRechodev@echo.nasa.govGenesis GPS Occultation Observations Level 1BThe Genesis GPS Occultation Observations Level 1B data set consists of
LEO-GPS (low-earth-orbiter satellites and Global Positioning System
satellites) radio occultation (limb sounding) atmospheric doppler and
bending data for use in computing atmospheric refractivity,
temperature, pressure, and water vapor profiles. LEOs collecting
occultation data include GFZ's CHAMP (CHallenging Minisatellite
Payload satellite) and CONAE's SAC-C. Data are available at the two
GPS frequencies, 1.2 and 1.6 GHz, at a time resolution of 1 second or
better. These are the Level 1B products of this radio occultation
data set.
The full set of products available include
* Level 0: Raw GPS data
* GPS data for orbit determination in RINEX format
* Orbit products
* Level 1A: Atmospheric phase delay and signal amplitude
* Level 1B: Atmospheric doppler shift and bending
* Level 2: Atmospheric refractivity, temperature, pressure, water vapor
pressure profiles, and comparisons to weather analysis and
radiosondes.
CHAMP and SAC-C each carry a JPL Blackjack GPS receiver and a
rearward-facing antenna to record the signals of GPS satellites
setting behind the Earth's limb as the signal passes through the
atmosphere. (SAC-C also carries a forward-facing antenna, currently
inactive.) Typically over 200 of these "occultations" occur per day
per LEO with fairly uniform global distribution. By measuring the
precise phase delay experienced by the GPS signals, and using precise
clock-offset and orbit information, the atmospheric component of the
phase delay can be extracted. Assuming local spherical symmetry about
the tangent point, inversion of the atmospheric phase delay phase
measurements during an occultation yields atmospheric refractivity
profiles, which can be converted to temperature and pressure profiles
between 60 km and the middle troposphere, and, with independent
knowledge of temperature, into water vapor density in the middle and
lower troposphere.
Valuable properties of radio occultation measurements of atmospheric
profiles include:
* Self-calibrating, making them ideal for climate detection.
* Sub-kilometer vertical resolution.
* Sub-Kelvin temperature accuracy below 45 km.
* All-weather operation
* Independent height and pressure data allowing computation of
geopotential heights and derived wind fields
* Concurrent global coverage with a small constellation
Comparison of CHAMP and SAC-C to National Center for Environmental
Prediction (NCEP) and the European Center for Medium-range Weather
Forecast (ECMWF) analyses show that GPS occultation temperature profiles
are consistent with the models to better than 0.5 K in the mean, and
better than 1.5 K in standard deviation.
Smoothed atmospheric doppler and bending angle are useful intermediate
products between the Levels 1A and 2 products. These products are
provided at a sample rate of 1/sec or better for the 1.6 GHz
frequency, and at a rate of 1/sec for the 1.2 GHz frequency. The 1.2
GHz data has lower SNR than the 1.6 GHZ data, and is used to subtract
the effect of the ionosphere. Atmospheric bending with the effect of
the ionosphere removed, and impact parameter are also provided.
Bending angle and impact parameter are computing assuming local
spherical symmetry.C1214611007-SCIOPS2001-02-11T00:00:00.000Z/Genesis GPS Occultation Observations Level 1BJPL_Genesis_L1BNot providedSCIOPSNASA/JPL/GENESISNASA/JPL/GENESISCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse0.78000005org.geoss.geoss_data-coretruehttps://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214611008-SCIOPSCMRechodev@echo.nasa.govGenesis GPS Occultation Observations Level 2The Genesis GPS Occultation Observations Level 2 data set contains
profiles of atmospheric temperature, pressure, refractivity, and water
vapor pressure with resolution of about a kilometer, derived from
LEO-GPS (low-earth-orbiter satellites and satellites of the Global
Positioning System) radio occultation (limb sounding) data. Similar
profiles from NCEP and ECMWF analyses are also included. LEOs
collecting occultation data include GFZ's CHAMP (CHallenging
Minisatellite Payload satellite) and CONAE's SAC-C. These are the
Level 2 products of this radio occultation data set.
The full set of products available include
* Level 0: Raw GPS data
* GPS data for orbit determination in RINEX format
* Orbit products
* Level 1A: Atmospheric phase delay and signal amplitude
* Level 1B: Atmospheric doppler shift and bending
* Level 2: Atmospheric refractivity, temperature, pressure, water vapor
pressure profiles, and comparisons to weather analysis and
radiosondes.
CHAMP and SAC-C each carry a JPL Blackjack GPS receiver and a
rearward-facing antenna to record the signals of GPS satellites
setting behind the Earth's limb as the signal passes through the
atmosphere. (SAC-C also carries a forward-facing antenna, currently
inactive.) Typically over 200 of these "occultations" occur per day
per LEO with fairly uniform global distribution. By measuring the
precise phase delay experienced by the GPS signals, and using precise
clock-offset and orbit information, the atmospheric component of the
phase delay can be extracted. Assuming local spherical symmetry about
the tangent point, inversion of the atmospheric phase delay phase
measurements during an occultation yields atmospheric refractivity
profiles, which can be converted to temperature and pressure profiles
between 60 km and the middle troposphere, and, with independent
knowledge of temperature, into water vapor density in the middle and
lower troposphere.
Valuable properties of radio occultation measurements of atmospheric
profiles include:
* Self-calibrating, making them ideal for climate detection.
* Sub-kilometer vertical resolution.
* Sub-Kelvin temperature accuracy below 45 km.
* All-weather operation
* Independent height and pressure data allowing computation of
geopotential heights and derived wind fields
* Concurrent global coverage with a small constellation
Comparison of CHAMP and SAC-C to National Center for Environmental
Prediction (NCEP) and the European Center for Medium-range Weather
Forecast (ECMWF) analyses show that GPS occultation temperature
profiles are consistent with the models to better than 0.5 K in the
mean, and better than 1.5 K in standard deviation.C1214611008-SCIOPS2001-02-11T00:00:00.000Z/Genesis GPS Occultation Observations Level 2JPL_Genesis_L2Not providedSCIOPSNASA/JPL/GENESISNASA/JPL/GENESISCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse0.78000005org.geoss.geoss_data-coretruehttps://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586610-SCIOPSCMRechodev@echo.nasa.govHigh Rate CHAMP GPS Occultation DataThis data set comprises CHAMP GPS-SST data of a sample rate of 50 Hz,
generated by decommutation and decoding the CHAMP science dump data.
This raw data passed no quality control.C1214586610-SCIOPS2001-02-11T00:00:00.000Z/High Rate CHAMP GPS Occultation DataCH-AI-1-HR9.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse1.7160001https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586609-SCIOPSCMRechodev@echo.nasa.govHigh rate GPS ground tracking dataThis data set comprises GPS high rate ground data of a sample rate of 1 sec,
generated by decoding the original measurement data. This raw data passed no
quality control. The data are given in the Rinex 2.1 formatC1214586609-SCIOPS2000-04-10T00:00:00.000Z/High rate GPS ground tracking dataCH-AI-1-GPS-01S0.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-45.69 -63.51 78.87 170.52falsefalsefalsefalsefalsefalsefalsefalse0.65https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586739-SCIOPSCMRechodev@echo.nasa.govLow Rate CHAMP GPS-SST DataThis data set comprises CHAMP GPS-SST data of a sample rate of 10 sec,
generated by decommutation and decoding the CHAMP science dump data.C1214586739-SCIOPS2000-03-28T00:00:00.000Z/Low Rate CHAMP GPS-SST DataCH-OG-1-SST9.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse1.43https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586623-SCIOPSCMRechodev@echo.nasa.govMedium Rate CHAMP GPS Occultation DataThis data set comprises CHAMP GPS-SST data of a sample rate of 1 sec,
generated by decommutation and decoding the CHAMP science dump data.
This raw data passed no quality control.C1214586623-SCIOPS2001-02-11T00:00:00.000Z/Medium Rate CHAMP GPS Occultation DataCH-AI-1-MR9.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse1.7160001https://cmr.earthdata.nasa.gov/opensearch/collections.atom?uid=C1214586624-SCIOPSCMRechodev@echo.nasa.govOccultation link related TEC dataCHAMP data, Atmosphere and Ionosphere.C1214586624-SCIOPS2001-01-01T00:00:00.000Z/2005-05-23T23:59:59.999ZOccultation link related TEC dataCH-AI-3-IVP0.0SCIOPSDE/GFZ/ISDCDE/GFZ/ISDCCARTESIAN-90 -180 90 180falsefalsefalsefalsefalsefalsefalsefalse0.78000005