A proposal of AWS maintenance and periodic calibration tools and installation of ARGs for Radar QPE calibration

Automatic weather station (AWS) can automatically observe surface weather elements and can transmit the data to data center through internet or mobile phone lines. Therefore, it is suitable to monitor mesoscale disturbances and precipitation, in particular. Viet Nam Meteorological and Hydrological Administration (VNMHA) currently operates AWS and Automatic Rain Gauge (ARG) networks by multi–national donors. However, the instruments were not calibrated after installation, and it was difficult to perform maintenance on a regular basis, so technical problems often occurred in their observation accuracy and reliable operation. Japan–Vietnam joint technical project between Japan International Cooperation Agency (JICA) and VNMHA started in May 2018. As part of this project, the introduction of AWS maintenance and traceability technology, and ARG network for the calibration of radar rainfall quantitative estimation (QPE) were proposed. In this paper, we discuss the current situation of AWS and ARG network in VNMHA. Next, we will explain the maintenance and cyclic calibration of the instrument proposed in this project. Furthermore, we will explain the installation plan of the ARGs to calibrate two radar data in Phu Lien and Vinh for the development of QPE. Installation of ARGs has been achieved with cooperative works of VNMHA staffs and JICA experts. So, we introduce their activities for each step from site survey to pre–operational evaluation. Furthermore, we will discuss future issues for stable and accurate observations of AWS and ARG networks.