Software Development Specific to Environmental Science

Industrial Source Model (IS³)

The IS³model provides a visual representation of an acoustic field pattern across any three-dimensional surface factoring in the effects of topographic and structural interference, apparent receptor elevation, static reflection from objects, multiple material attenuative sources, variable propagation rates and source types, and atmospheric scattering. The program can accurately display intensity patterns for a wide array of frequencies from DC to hypersonic. A little known secret of the program is that it can model the radiation damping from vibration sources with only slight modifications to the constitutive property input deck.

The computer plot to the right is typical of the output from the ISE Industrial Source Model (IS³). This plot, which is the compilation of well over 10,000,000 sampling points provides an acoustical map of the affected project in minute detail. Each color represents a different sound level as measured five feet above the ground.

Here, a concrete batch facility consisting of four mixing and service areas is examined for property line compliance. The facility has a large block wall along its entire perimeter - except for the entrance and exit area. Clearly evident is the onsite attenuation due to the perimeter wall as well as leakage out the entrance and areas of acoustic shadowing (the pink areas).

This type of modeling makes for easy determination of a proposed projects compliance state with no guesswork. A picture is worth a thousand words - and the IS³ model provides one spectacular picture!!!

Current version is 4.0.

Platform: PowerBasic CC for MS DOS through Win XP. ISE is currently porting code into FORTRAN for multi-threaded OS X platform for Mac.

LightMap

The diffractive technology developed over the years within the IS³ model has also been revisited in our new Lightmap 3.0 program which provides foot-candle intensities across any surface. Click here to see a sample output of the program (in horizontal foot-candles at 36-inches) for a large auto plaza project.

LightMap is an effective tool in identifying artificial and natural light distribution across an area of interest and is readily capable of capturing the smallest details of shadow and glare. The program need not be limited to just the visible spectrum of light (roughly 700 nm to 400 nm) and can in fact generate field patterns for any non-ionizing radiation source (i.e., wavelengths from 1 mm to approximately 750 nm – the boundary of the near infrared).

The new LightMap 3.0 program represents a complete revision and optimization of the code into FORTRAN 95 from it's earlier PowerBASIC origins. The LightMap program algorithm was recoded with an eye towards massively parallel processing since the number of diffraction calculations required to correctly determine a solution is staggering. The example project shown required well over 1.2 billion iterations (or roughly 5 billion numerical calculations per model run). The new parallel FORTRAN code can execute the model on a Mac 2 x 3.2 GHz Quad-Core Intel Xenon Mac in a little under two minutes. The older (non parallel) BASIC code took over 21 hours on a Dual-Core HP 2.7 GHz Athlon running Windows XP. It ran even slower on the same HP machine running Vista.

ISE currently supports two versions of this program. The newer version 3.0 was recoded into FORTRAN 95 using the Absoft compiler and is downward compatible from OS X 10.5 to 10.1 (there is no legacy support for OS 9.xx). The older version 2.0 is in PowerBasic CC for MS DOS through Win XP. There are no numerical output differences between the codes except for platform support and size and speed capabilities (LightMap 3.0 can handle much larger models at a fraction of the computational cost).

Impulsive Noise Program (IMP)

The IMP 1.0 program characterizes the extremely short duration supersonic pulses produced by highly discontinuous acoustical events. The IMP program is a steady state shock flow program and that has been used by ISE for years to predict the acoustic pressure produced by supersonic gas flow in pipes.

The IMP program replaces the OBLSHK 1.0 program to determine the entropy and thermodynamic parameters of generalized normal and oblique shock waves. This program was later modified to determine the sound pressure level due to oblique shock generation associated with high-pressure gas pipeline blow down.

Current version is 1.0.

Platform: MS Excel (no VBA), portable to any platform running MS Excel.

Fresnel

Fresnel Barrier Attenuation Algorithm based upon FHWA RD-77-108. Although based on a traffic noise report, the Fresnel 1.0 algorithm is generic in nature and has equal applicability to all potential field problems where diffraction is involved.

Current version is 1.0.

Platform: PowerBasic CC for MS DOS through Win XP.