Library VTD for computation of VLBI time delay

Introduction

Library VTD computes a priori VLBI time delay and delay rate with precision needed for geodetic applications. Terms which contributes to delay at the level 10^-13 sec for delay and 10^-15 for delay rate are kept. The accuracy of VTD is determined by the accuracy of a priori values. If the apriori site positions, source coordinates, EOP, tropospheric path in zenith direction were perfect, the theoretical time delay and delay rate would be accurate to that level. Library VTD also computes the Doppler frequency shift for the Solar system objects.

License: GNU Public License.

Download

The latest version vtd-20210505.tar.bz2

Documentation

The overview: README.

Installation instruction: INSTALL.

Introduction to (VTD) package vtd_intro.html (or PDF).

Description of keywords of VTD control file language vtd_keywords.html (or PDF).

Synopsis of keywords of VTD control file language vtd_keywords.syn.

Formats of apriori files for VTD vtd_apriori.html (or PDF).

VTD a priori files management. vtd_apriori_files_management.txt.

Description of the algorithm for computing VLBI time delay and delay rate with picosecond accuracy vtd_alg.pdf.

Change log Change log.

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This web page was prepared by Leonid Petrov ()
Last update: 2021.05.05_21:10:32