NASA Goddard Space Flight Center Geodesy and Geophysics Laboratory

Network Earth Rotation Service

The Network Earth Rotation Service (NERS)is an on-line tool for dissemination of the Earth's orientation parameter that describes irregularity in the Earth's rotation that are determined from observations and partly from numerical weather models. The service provides an automatic access to the parameter that describes the Earth's rotation from 1976.01.01 through 48 hours in the future.

Since the irregularities in the Earth's rotation are caused by motion of the hydrosphere and the atmosphere no deterministic model can describe them with the accuracy comparable with accuracy of observations. The Earth's rotation is constantly monitored by space geodesy observations. The NERS assimilates the results of data analysis of Very Long Baseline Interferometry (VLBI), Global Navigation Satellite Systems, and the output of numerical models, computes short term EOP forecast, takes the long-term EOP forecast distributed by the Paris Observatory and distributed the results in a form convenient for users. See the acknowledgment section for the list of agencies that provides the results of data analysis used by the NERS.

See the Earth rotation explained for a discussion about variations in the Earth's rotation.

Available services:

The atmospheric angular momentum on-line service. The exchange angular momentum between the lithosphere, atmosphere, and the ocean is one of the factors that cause irregularities in the Earth's rotation.

Web interface to the Network Earth Rotation Service. It displays selected parameters of the Earth's rotation at the specified epoch.

Real time Earth rotation service. Shows the Earth orientation now based on the forecast. The forecast rms errors of the Earth orientation parameters at the current moment:
1.1 nrad for components 1,2 (polar motion) and
2.5 nrad for component 3 (axial component, or UT1),
which corresponds to 7 and 16 mm at the Earth's surface respectively.

Generate Earth orientation parameter series with a specified time range and specified time step.

Current latency of the NERS.

Using the Network Earth rotation service.

How to use the Network Earth Rotation Service.

Client software for automatic computation of the Earth orientation parameters.

See document how does the Network Earth Rotation Service is working for explanation what is going on under the hood.

Acknowledgment

This project is supported by NASA Earth Surface & Interior program, grant NNX15AC10G.

The contribution of the following agencies is used by the NERS:

IAA — Institute of Applied Astronomy provides estimates of UT1 angle from Russian Intensive VLBI experiments.

NASA GSFC VLBI group — provides UT1 and polar motion from 24 hour and IVS intensive VLBI experiments

Paris observatory — provides the C04 time series and long term EOP prediction.

IGS — International Global Navigation Satellite Services rapid and ultra-rapid estimates of the polar motion.

CODE — Center for Orbit Determination in Europe (CODE) provides estimates of polar motion.

GMAO NASA Global Modeling and Assimilation Office provides the output of assimilation numerical weather model and short-term weather forecast.

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Last update: 2023.09.18_19:37:27