Design and Implementation of a Dynamic System of Retrieving and Updating IERS Data

It is a fundamental issue in astronomical research to achieve high-precision calculations of target positions. To fulfill the requirements of high-precision calculations of positions in pipeline data processing for the Chinese Solar Radio Heliograph (CSRH), in this paper we propose a dynamic system of automatically retrieving and updating data to obtain useful parameter values from the IERS website. The method can automatically download and analyze a text file published on the IERS website. Values of the needed parameters, including the earth orientation, leap second, and polar motion, can be extracted from canonical expressions of the text file and saved to a specified local file. The values include measured and predicted ones. With the method a local database of IERS parameter records since December 31, 2004 has been established. The database is being updated weekly in the automated mode by checking the IERS website. Our study provides a general method to maintain astronomical data essential to high-precision calculations of target positions. It avoids the conventional need to manually maintain such data. It is valuable to the design of pipeline data processing for the CSRH. The routines for the method were written with the Python language and can be easily integrated into other astronomical software packages.