San Diego County Visualizes Wind Data with PV-WAVE

The User

The primary goal of the San Diego County Air Pollution Control District is to protect the public from the harmful effects of air pollution and to achieve and maintain air quality standards. In order to make decisions that protect the public and to report accurate information to the Environmental Protection Agency (EPA), air pollution control authorities need good ways of analyzing and displaying data. Of special interest are the prevailing winds above San Diego County. The District uses air pollution and wind data as historical records in order to evaluate trends and origins of contaminated air. Often, transported air pollution is carried on the wind from Los Angeles to San Diego. The District is responsible for documentating air pollution that originated elsewhere, thereby avoiding EPA-administered fines for air pollution that is not organic to San Diego County.

The Problem

To provide the EPA with accurate information on prevailing winds, the Air Pollution Control District uses a “windrose chart.” This chart tells authorities how frequently the wind blows at a certain speed in a given direction. There are many applications and programs for studying windrose charts, however, most analyze only one specific dataset at a time. “For the type of work that we do, it was necessary to use a program that can read data in the ‘AIRS’ format, the universal format for the air monitoring community,” said Jean Timmerman, an air resources specialist. “PV WAVE from Visual Numerics, Inc., was the only commercially-available program the District found that could read data from the many different sources that use the AIRS data format.”

The Solution

“My group was first attracted to Visual Numerics after learning that PV-WAVE had worked successfully in other projects within the Air Pollution Control District,” Timmerman said. “Then, after seeing a successful demonstration with EPA data from Colorado, we became even more interested. We eventually decided to implement PV-WAVE for three primary reasons: it’s a flexible product, giving us the ability to import many data formats and generate multiple views of windrose data; it’s a complete solution combining state-of-the-art visualizations with advanced data analysis tools; and it’s a stable product, meaning we won’t lose valuable development time dealing with system failures or bugs.”

PV-WAVE is an open environment for developing and deploying Visual Data Analysis (VDA) applications that help customers turn raw data into meaningful information. These VDA applications let users visualize and manipulate complex or extremely large data sets to detect and display patterns, trends, anomalies, and other vital information. PV-WAVE includes hundreds of mathematical and statistical analysis routines from Visual Numerics’ IMSL Numerical Libraries, as well as image processing, signal processing, mapping, and general data manipulation features. Engineers, scientists, business analysts, and software developers access this robust and extensive set of functions through an array-oriented programming language. PV-WAVE also includes advanced graphical user interface development tools that facilitate the construction of intuitive front-ends, making the product’s functionality easily accessible to others in an organization.

Benefits & Results

“We found that PV-WAVE's plotting capabilities were perfect for reading in and making sense of windrose chart data,” Timmerman said. Monitoring winds, however, is not the only work done by the Air Pollution Control District. “We also encounter a number of graphics-type problems during our daily routine, including the need to visualize real-time air quality data. For these reasons, we needed more than a pre-built application that restricted customization. We needed a tool that offered powerful data analysis and visualization functionality, which could be customized to our specific needs. Because PV-WAVE is a fourth-generation programming language, it gives us the ability to write applications that address our specific data analysis problems,” she added.

PV-WAVE provides significant value not only because of its powerful visualization tools, but also the strong data analysis capabilities offered through Visual Numerics’ IMSL Numerical Libraries, which are included in PV-WAVE. Other key strengths, according to Timmerman, are PV WAVE’s ability to read many different data formats from many different sources, and the ability it gives users to develop a customized solution.

Client Satisfaction

Visual Numerics’ technical support staff has been very accommodating, according to Timmerman. “When we call for assistance, they quickly provide the knowledge and expertise we need to move forward. That’s critical when working under tight deadlines, as I usually am. Furthermore, the software’s online documentation is excellent. Most questions are easily answered without leaving my desk.”