Performance

The original large scale filtering technique as well as the modified technique was performed on a set of radar reflectivity images. Each image in the sequence was the lowest elevation scan of successive volume scans by a Weather Service Radar, observed in Fort Worth, Texas on May 8, 1995. The polar data from the radar were mapped into a Cartesian grid with each pixel being approximately 1km$\times$1km and clipped at a range of 256km from the radar.

We filtered a set of seven $512\times512$ radar reflectivity images using both techniques on a single-processor Sun Sparc Ultra 10. For a fairer comparison, the original technique was implemented almost completely using integer arithmetic while the modified technique uses double-precision floating point operations.