Description:

Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) Geocenter Time Series Product from the NASA Crustal Dynamics Data Information System (CDDIS). DORIS is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon. DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. DORIS observations from a global network can be utilized for a variety of products. Analysis Centers (ACs) of the International DORIS Service (IDS) retrieve DORIS data on a regular basis to compute various DORIS products from data generated by the DORIS beacons supporting the IDS network, including the time series of coordinates of the geocenter or the origin of the terrestrial reference frame. The IDS Analysis Center Coordinator combines these solutions to produce an official IDS geocenter product. The geocenter time series are available in text format.

Links:

• Data link
• Metadata link
• undefined

Temporal Extent:

Start: 1992-01-01T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

CDDIS Short Name: DORIS_IDS_geocntr_prod Version ID: 1 Unique ID: C1602818278-CDDIS

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Description:

Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) Station Position Time Series Product from the NASA Crustal Dynamics Data Information System (CDDIS). DORIS is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon. DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. DORIS observations from a global network can be utilized for a variety of products. Analysis Centers (ACs) of the International DORIS Service (IDS) retrieve DORIS data on a regular basis and after producing the weekly SINEX files using the current ITRF, compute station position time series solutions for the DORIS beacons supporting the IDS network. The IDS Analysis Center Coordinator combines these individual AC solutions to generate the official IDS DORIS network time series solution in the IDS STCD (Station Coordinates Difference) format.

Links:

• Data link
• Metadata link
• undefined

Temporal Extent:

Start: 1992-01-01T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

CDDIS Short Name: DORIS_IDS_time_series_pos_prod Version ID: 1 Unique ID: C1544926730-CDDIS

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Description:

Station position time series solutions in DORIS Station Coordinate Difference (STCD) format derived from analysis of Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) data. These products are the generated by analysis centers in support of the International DORIS Service (IDS).

Links:

• Data link
• undefined
• Metadata link

Temporal Extent:

Start: 1990-03-31T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

CDDIS Short Name: DORIS_IDS_sta_coord_prod Version ID: 1 Unique ID: C1000000080-CDDIS

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Description:

Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) Data (multi-day files) from the NASA Crustal Dynamics Data Information System (CDDIS). DORIS is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon. DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. The data records also contain information about any corrections that may have been applied during the processing phase, such as for the ionosphere, troposphere, and satellite center of mass, among others. Furthermore, meteorological measurements (e.g., temperature, relative humidity, ground pressure) recorded by instruments co-located with the ground-based beacons are included with the DORIS data and can be used to determine the tropospheric correction. DORIS data in the original format are also supplied to the data center in multi-day files, corresponding to the mission’s data processing arc, and are forwarded approximately 20 days after the end of the last observation day contained in the file. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/DORIS/DORIS_data_holdings.html.

Links:

• Data link
• Metadata link
• undefined

Temporal Extent:

Start: 1992-01-01T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

CDDIS Short Name: DORIS_multiday_data Version ID: 1 Unique ID: C1538790162-CDDIS

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Description:

The products offered by the Hydroweb project consist of continuous, long-duration time-series of the levels of large lakes with surface areas over 100 km2, reservoirs and the 20 biggest rivers in the world.The operational measurement series are updated no later than 1.5 days after a new altimetry measurement becomes available. They cover about 80 large lakes and 300 measurement points along about 20 major rivers.The research measurement series are updated at regular intervals according to the progress made with processing by the LEGOS laboratory. They cover about 150 large lakes and 1,000 measurement points along about 20 major rivers.Continental waters account for only 0.65% of the total amount of water on Earth, 97% being stored in the oceans and 2.15% in the cryosphere. However, these waters have a significant impact on life on Earth and household needs. They also play a major role in climate variability. Water on Earth is continually recycled through precipitation, evaporation and run-off towards the sea. The increasingly accurate characterisation of the water cycle on land surfaces enables more accurate forecasting of the climate and more careful control of global water resources (human consumption and activities such as agriculture, urbanisation and the production of hydroelectric power, for example). Radar echoes over land surfaces are hampered by interfering reflections due to water, vegetation and topography. As a consequence, waveforms (e.g., the power distribution of the radar echo within the range window) may not have the simple broad peaked shape seen over ocean surfaces, but can be complex, multi-peaked, preventing from precise determination of the altimetric height. If the surface is flat, problems may arise from interference between the vegetation canopy and water from wetlands, floodplains, tributaries and main river. In other cases, elevated topography sometimes prevents the altimeter to lock on the water surface, leading to less valid data than over flat areas. The time series available in Hydroweb are constructed using Jason-2 and Saral GDRs. The basic data used for rivers are the 20 or 40Hz data(“high rate” data).To construct river water level time series, we need to define virtual stations corresponding to the intersection of the satellite track with the river. For that purpose, we select for each cycle a rectangular “window” taking into account all available along track high rate altimetry data over the river area. The coordinate of the virtual station is defined as the barycenter of the selected data within the “window”. After rigourous data editing, all available high rate data of a given cycle are geographically averaged. At least two high rate data are needed for averaging otherwise no mean height is provided. Scattering of high rate data with respect to the mean height defines the uncertainty associated with the mean height.The water level and volume time series is operationally updated less than 1.5 working days after the availability of the input altimetry data, for some virtual stations on rivers. Other virtual stations are monitored on a research mode basis. [https://www.theia-land.fr/fr/projets/hydroweb]

Links:

• Data link
• CNES_http__cnes.fr_ark_68059_0b7a761c3e62fd4332cd4f66eff0c845...

Temporal Extent:

Start: 1992-01-01T00:00:00.000Z

Spatial Extent:

Minimum Bounding Rectangle: -90 -180 90 180

CEOS_EXTRA Short Name: CNES_http__cnes.fr_ark_68059_0b7a761c3e62fd4332cd4f66eff0c845_IDN Version ID: 1.2 Unique ID: C2226555501-CEOS_EXTRA