This data set contains GPS readings over Antarctica using the Trimble Trimflite differential GPS Navigation System. The readings include latitude, longitude, track, ground speed, off-distance, Positional Dilution of Precision (PDOP), GPS height, easting, northing, and time taken. The data were collected by scientists working on the Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project, which is funded by the National Science Foundation (NSF) and the Natural Environment Research Council (NERC), with additional support from NASA Operation IceBridge.

This data set contains elevation, roll, pitch, and heading measurements over Antarctica using the Ashtech GG24 GPS+ receiver and the Systron and Donner MMQ-50 Inertial Measurement Unit (IMU). The data were collected by scientists working on the Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project, which is funded by the National Science Foundation (NSF) and the Natural Environment Research Council (NERC), with additional support from NASA Operation IceBridge.

This data set, part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Program, contains 6 and 12 day surface velocity estimates for the Greenland Ice Sheet and periphery. Velocities are derived from images acquired by the European Space Agency (ESA) Copernicus Sentinel-1A and Sentinel-1B satellites. See Greenland Ice Mapping Project (GrIMP) for related data sets.

This dataset provides seasonal averages of a global planetary boundary layer (PBL) height climatology derived from the COSMIC/FORMOSAT-3 and TerraSAR-X Global Positioning System (GPS) radio occultation (RO) measurements from June 2006 to December 2015. The COSMIC/FORMOSAT-3 mission consists of a six-satellite constellation launched in 2006. Each satellite carries the IGOR GPS receiver and is equipped with fore and aft looking antenna to track both setting and rising occultations. The constellation provides globally distributed measurements across different local times. The TerraSAR-X (TSX) is a X-band SAR imaging satellite with GPS RO being a secondary measurement. It also carries an IGOR receiver and has been collecting GPS RO measurements since 2011. The instrument tracks the L-band microwave signal broadcast by a GPS satellite in a limb-viewing geometry. The IGOR receivers on COSMIC and TSX are capable of tracking the GPS signals in open loop through the middle to lower troposphere, which is essential for obtaining data with high quality for PBL height estimation, especially at low latitudes. The refractivity profiles from COSMIC and TSX form the basis for this PBL height product. For each occultation, the PBL height is calculated as the height where the vertical gradient of the refractivity (dN/dz) is minimum. This algorithm is designed to locate the height where a large vertical change in refractivity occurs, corresponding to the transition from the free troposphere to the PBL. More details can be found in Ao et al. (2012). Each PBL height is associated with a time (starting time of the occultation) and location (latitude and longitude of the tangent point at the minimum altitude). The PBL height data are then binned into 2 degree x 2 degree latitude/longitude regions and averaged to produce the mean and standard deviation values in the climatology products. The refractivity profile has a vertical resolution of about 200 m and represents an along path horizontal averaging of ~100 km. Thus, occultations with tangent points near the coast may represent averaging over both land and ocean and should be interpreted with care. The refractivity gradient method used here is not the only method that can be used to estimate the PBL height. Other algorithms have been proposed, including looking at "breakpoint" instead of minimum gradient, wavelet covariance transform, and using variables like bending angles or specific humidity instead of refractivity. However, the basic principle is the same. The difference between the different algorithms is small where the PBL is well-defined, with a strong capping inversion.

This data set contains elevation, roll, pitch, heading, north-south acceleration, east-west acceleration, and vertical acceleration measurements over Antarctica using the Systron and Donner MMQ-50 Inertial Measurement Unit (IMU) and the Topcon GB-1000 GPS+ receiver. The data were collected by scientists working on the Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project, which is funded by the National Science Foundation (NSF) and the Natural Environment Research Council (NERC), with additional support from NASA Operation IceBridge.

This data set presents polarimetric observations of comet 1P/Halley reported as normalized Stokes parameters. All data were contributed by a single observer, A. Dolphus, working at the European Southern Observatory. This revised version of the data set includes updated documentation and data formats.

This collection contains Jason-3 orbital information files, produced by CNES for offline (IGDR, GDR) data production. For GPSP1, intermediate level-1 data files are in "RINEX" format and from the Global Positioning System (GPS) receiver and are used to compute precise GPS orbits for the spacecraft. For TLE: Two Line Element files are used to determine the position and velocity of the satellite. Within CLASS, they will be used directly to determine each orbit's equator crossing longitude and time which subsequently are used to support spatial search. For MOE and POE, medium-precision and precision orbital ephemeris files are from the DORIS system. These data may be may be subject to access restrictions.

The Polar-orbiting Operational Environmental Satellite (POES) series offers the advantage of daily global coverage, by making nearly polar orbits 14 times per day approximately 520 miles above the surface of the Earth. The Earth's rotation allows the satellite to see a different view with each orbit, and each satellite provides two complete views of a location around the world each day. The POES constellation of weather satellites is a joint effort between the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The Advanced Very High Resolution Radiometer (AVHRR) is a cross-track scanning system with five spectral bands having a resolution of 1.1 km and a frequency of earth scans twice per day (usually 0230 and 1430 local solar time) on NOAA and EUMETSAT satellites. There are three data types produced from the NOAA POES AVHRR. The Global Area Coverage (GAC) data set is reduced resolution image data that is processed onboard the satellite taking only one line out of every three and averaging every four of five adjacent samples along the scan line; the Local Area Coverage (LAC) data set is recorded onboard at original resolution (1.1 km) for part of an orbit and later transmitted to earth; and the High Resolution Picture Transmission (HRPT) is real-time downlink data. The EUMETSAT MetOp satellite series, initially launched on October 19, 2006, produces the same three data types as well as a fourth data type, Global Full Resolution Area Coverage (FRAC 1.1 km). The MetOp polar orbiting operational meteorological satellite system is the European contribution to the Initial Joint Polar-Orbiting Operational Satellite System (IJPS). AVHRR data provide opportunities for studying and monitoring vegetation conditions in ecosystems including forests, tundra and grasslands. Applications include agricultural assessment, land cover mapping, producing image maps of large areas such as countries or continents, and tracking regional and continental snow cover. AVHRR data are also used to retrieve various geophysical parameters such as sea surface temperatures and energy budget data.

The Polar-orbiting Operational Environmental Satellite (POES) series offers the advantage of daily global coverage, by making nearly polar orbits 14 times per day approximately 520 miles above the surface of the Earth. The Earth's rotation allows the satellite to see a different view with each orbit, and each satellite provides two complete views of a location around the world each day. The POES constellation of weather satellites is a joint effort between the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The Advanced Very High Resolution Radiometer (AVHRR) is a cross-track scanning system with five spectral bands having a resolution of 1.1 km and a frequency of earth scans twice per day (usually 0230 and 1430 local solar time) on NOAA and EUMETSAT satellites. There are three data types produced from the NOAA POES AVHRR. The Global Area Coverage (GAC) data set is reduced resolution image data that is processed onboard the satellite taking only one line out of every three and averaging every four of five adjacent samples along the scan line; the Local Area Coverage (LAC) data set is recorded onboard at original resolution (1.1 km) for part of an orbit and later transmitted to earth; and the High Resolution Picture Transmission (HRPT) is real-time downlink data. The EUMETSAT MetOp satellite series, initially launched on October 19, 2006, produces the same three data types as well as a fourth data type, Global Full Resolution Area Coverage (FRAC 1.1 km). The MetOp polar orbiting operational meteorological satellite system is the European contribution to the Initial Joint Polar-Orbiting Operational Satellite System (IJPS). AVHRR data provide opportunities for studying and monitoring vegetation conditions in ecosystems including forests, tundra and grasslands. Applications include agricultural assessment, land cover mapping, producing image maps of large areas such as countries or continents, and tracking regional and continental snow cover. AVHRR data are also used to retrieve various geophysical parameters such as sea surface temperatures and energy budget data.

This dataset provides a seasonal average climatology of global planetary boundary layer (PBL) height derived from COSMIC/FORMOSAT-3, TerraSAR-X, KOMPSAT-5, and PAZ Global Positioning System (GPS) radio occultation (RO) measurements. The COSMIC/FORMOSAT-3 mission consists of a six-satellite constellation launched in 2006. Each satellite carries an Integrated GPS Occultation Receiver (IGOR) GPS receiver and is equipped with fore and aft looking antenna to track both setting and rising occultations. The constellation provides globally distributed measurements across different local times. The instrument tracks the L-band microwave signal broadcast by a GPS satellite in a limb-viewing geometry. The IGOR receivers are capable of tracking the GPS signals in open loop through the middle to lower troposphere, which is essential for obtaining data with high quality for PBL height estimation, especially at low latitudes. The refractivity profiles form the basis for this PBL height product. For each occultation, the PBL height is calculated as the height where the vertical gradient of the refractivity (dN/dz) is minimum. This algorithm is designed to locate the height where a large vertical change in refractivity occurs, corresponding to the transition from the free troposphere to the PBL. More details can be found in Ao et al. (2012). This is the latest version of this collection which supersedes previous versions.