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.
Using the Network Earth rotation service.
This project is supported by NASA
Earth Surface & Interior program, grant NNX15AC10G.
- 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
- Generate Earth orientation parameter
series with a specified time range and specified time step.
- Current latency of the NERS.
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.
— 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
- Astrogeo Center provides quarterly solution with
estimates of harmonic variations of the Earth orientation parameters from
processing VLBI data.
This page was prepared by Leonid Petrov
Last update: 2017.07.05_12:12:16