International Path Delay Service
The path delay service uses the output of numerical weather models and
computes slant path and zenith path delays in the atmosphere at radio,
infra-red or optic ranges, including dry and wet components. Handling
the output of numerical weather models is not an easy task: their size
exceed 1 Tb/year. The service solves for logistic problem of downloading
voluminous datasets, their preprocessing, performing CPU-intensive computations
at a dedicated server, and presenting the results in a form that can be used
for analysis of GNSS, SLR, DORIS, VLBI, radioastronomy, InSAR, air-born and
- The goal of the Path Delay Service is
to ingest outputs of numerical models, compute path delay through
the neutral atmosphere, and to disseminate the results for the entire
geodetic community on a regular basis, continuously, and with low
latencies. The service is provided free of charge, and
no registration is required.
- Slant path delay through the neutral atmosphere in a form of 3D
time series is provided for 459
geodesy sites. The dimensions runs over elevation, azimuth, and time.
In total, there are Configuration file /opt64/spd/share/spd_stat_service.conf does not exist
files to download from this site. To facilitate downloading files with slant
path delay, the list of URLs for downloading can be generating by filling a web form:
Downloading pre-computed time series
of slant path delay for 459
space geodesy sites. This form will generate a list URLs of individual
files or a control file for wget.
The series are updated within 1 hour of availability of new output of
numerical weather models.
Software SPD for computing computing slanted path delay through the neutral
atmosphere using the output of numerical weather models and for the end-user who
needs only interpolation of slant path delay for data reduction can be
This work was supported by NASA
Earth Surface & Interior program, grant NNX12AQ29G.
This page was prepared by Leonid Petrov
Last update: 2016.02.26_20:11:10