Weather radars are arguably the most expensive and most complex instruments within operational National Meteorological and Hydrological Services. They strengthen, enable, and indeed can revolutionize the services provided by NMHSs to economically and socially benefit society. Part A provides a guide to the development of an end-to-end radar program.
Required competencies include: Project leadership and management, meteorological, engineering, support and maintenance, R&D.
Costing: estimates are needed for the complete life cycle, which can be 15-40 years, divided into program phases. Annual estimates also needed.
Radar project is also distinguished from the program as a limited time endeavour with well-defined scope and resources, e.g. an upgrade.
Network design includes choice of technology, deciding how many and where to install radars, all in relation to user requirements, potential advantages from collaborative networking domestically and internationally, and contributing towards integrated observing systems and networks.
Radar can see into a thunderstorm in three dimensions every few minutes. No other meteorological sensor can do this. The structure and shape of the reflectivity is used to diagnose storm severity and to issue warnings.
Vol II - Weather Radar Technology
Target audience: Decision makers, managers, engineering and technical practitioners, scientists
A complete weather radar system consists of combined technological solutions that provide information supporting well-defined user requirements.
As such, the system comprises: the radar instrument, radome, tower, personnel and equipment shelter(s), power, reserve power, ancillary systems (e.g. climate control, lightning protection, security), communications, control and data processing software, computational resources, data storage/archive.
Strategic decisions on weather radar technology need to be made on: wavelength (for operational systems commonly X, C, or S bands), transmitter type (magnetron, klystron, solid state), beam width, sensitivity, “type”. Today, polarimetric (or dual-polarization) technology is established as the mainstream weather radar type. It is difficult to buy a weather radar that does not have polarimetric and Doppler capabilities.
Examples of emerging weather radar technologies are pulse-compression techniques (already common in places) and phased array antennas.
Parabolic antenna with three struts supporting the feed horn.
Vol III - Weather Radar Procurement
Target audience: Decision makers, managers, procurement specialists, engineering, technical, and scientific support to the procurement process
When you go shopping for a weather radar, how can you be sure you will really get a weather radar and not something else? Can you be assured that your new radar will have relevant, contemporary, and up-to-date features? The objective of Part C is to describe and provide examples of different approaches to weather radar procurement.
The greatest challenge when implementing weather radars will be that of human resources (availability of highly qualified people) and intellectual capacity (technical and meteorological). Training and other capacity building activities need to be part of strategic planning on a 5+ year time scale and be included in the radar procurement or project.
Included in weather radar procurement (other than radar instrument): infrastructure and civil works, project management, warranty period, support and maintenance, different levels of training, responsibility for configuration/data quality, acceptance testing, spares, life-cycle management, upgrade plan, integration with NMHS infrastructure, software/application development, auxiliary meteorological sensors (on/off site).
Vol IV - Weather Radar Siting, Configuration and Scan Strategies
Target audience: People who are in the process of getting their first weather radar.
Congratulations! You have money to buy a radar, and you know roughly where to put it. This part of the BPG walks you through how you know you have the right hill (site and access road), how you make sure your radar can measure when it is up and running (horizon and permissions), how to get the radar data to its users (telecommunications) and how to keep it running even when thunderstorms cut off your normal power supply. And it gives you suggestions for how to measure: scan strategy is always a compromize.
Some numbers, not from the guide but underlining its importance: cost of the site can be 30-500% of the radar purchase cost. Cost of keeping the radar running is annually 5-10% of the purchase cost.
Factors affecting weather radar site quality, some configuration choices, and data quality. Many of these factors are also being addressed in Part F.
Vol V - Weather Radar Calibration, Monitoring and Maintenance
Target audience: Operations, monitoring and maintenance practitioners and planners
Weather radars (should) deliver quantitative data about the hydrometeors in the atmosphere, as well as the location in the 3-D space where it occurs.
So calibration has to deal with the return of the transmitted radar pulse and the navigation, ie. the pointing of the beam. Basis for the calibration of the wanted signal is the electrical (“legacy”) calibration in terms of explicitly measuring powers, losses etc. Especially for dual-polarization radars this is not sufficient. The known returns from external sources are used to cover this gap. Amongst others, the signal from the sun and the returns from stratiform rain (determined by distrometers) are used for calibration. The calculated sun position is the reference today for monitoring pointing accuracy. Monitoring is the continuous surveillance of the system functions and the results can be partly used for calibration as well. (Preventive) maintenance is the basis for high availability and covers not only mechanics, but also analog components as well as IT.
This part provides processing methods to make radar product from raw moment data observed by weather radars. At first, noise and spurious echoes should be removed from raw moment data by quality control processing. Then radar data products such as distributions of rain rate and hydrometer class are derived from quality controlled (QC) moment data. Compositing process are used for making wide-coverage products. The characteristics and limitations of each processing are also described.
In an end-to-end perspective, our ends are defined as basic QC of moment data to quantitative precipitation estimation (QPE), together with identifying suitable data quality assessment metrics for each method.
Vol VII - Weather Radar Data Representation and International Exchange
Target audience: Decision makers, IT experts, radar application developers, radar data users
This volume provides guidance on the representation of weather radar data in a standardized format, including identification of the data types and associated metadata which are required to support a broad range of operational and scientific applications. A harmonized approach to representing data quality is included. Adoption of the new CfRadial 2.0 file format is recommended. This format implements the WMO Information and Data Models for Radial Radar Data which were also produced by IPET-OWR and the earlier WMO Task Team on Weather Radar Data Exchange.
Methods and technologies which may be used to implement international weather radar data exchanges are identified, and other relevant issues such as data licensing and the management of site metadata (through the WMO Radar Database) are discussed.
Vol VIII - Operational Weather Radar Glossary of Terminology
