Irma 5.1 multisensor signature prediction model

Abstract

The Irma synthetic signature prediction code is being developed to facilitate the research and development of multisensor systems. Irma was one of the first high resolution Infrared (IR) target and background signature models to be developed for tactical weapon application. Originally developed in 1980 by the Munitions Directorate of the Air Force Research Laboratory (AFRL/MN), the Irma model was used exclusively to generate IR scenes. In 1988, a number of significant upgrades to Irma were initiated including the addition of a laser (or active) channel. This twochannel version was released to the user community in 1990. In 1992, an improved scene generator was incorporated into the Irma model, which supported correlated frame-to-frame imagery. A passive IR/millimeter wave (MMW) code was completed in 1994. This served as the cornerstone for the development of the co-registered active/passive IR/MMW model, Irma 4.0. In 2000, Irma version 5.0 was released which encompassed several upgrades to both the physical models and software. Circular polarization was added to the passive channel and the doppler capability was added to the active MMW channel. In 2002, the multibounce technique was added to the Irma passive channel. In the ladar channel, a user-friendly Ladar Sensor Assistant (LSA) was incorporated which provides capability and flexibility for sensor modeling. Irma 5.0 runs on several platforms including Windows, Linux, Solaris, and SGI Irix. Since 2000, additional capabilities and enhancements have been added to the ladar channel including polarization and speckle effect. Work is still ongoing to add time-jittering model to the ladar channel. A new user interface has been introduced to aid users in the mechanism of scene generation and running the Irma code. The user interface provides a canvas where a user can add and remove objects using mouse clicks to construct a scene. The scene can then be visualized to find the desired sensor position. The synthetic ladar signatures have been validated twice and underwent a third validation test near the end of 04. These capabilities will be integrated into the next release, Irma 5.1, scheduled for completion in the summer of FY05. Irma is currently being used to support a number of civilian and military applications. The Irma user base includes over 130 agencies within the Air Force, Army, Navy, DARPA, NASA, Department of Transportation, academia, and industry. The purpose of this paper is to report the progress of the Irma 5.1 development effort.

Hemispherical reflectance model for passive images in an outdoor environment

“…Although the model is simple, it has the capability to simulate images of any complexity. We have developed Irma [4], a software package that simulates both active and passive sensors. Its passive channel is based on the reflectance model described in this paper, but with further simplification.…”

“…The final formalism should be utilized with this circumstance in mind. The details of implementing these can be found elsewhere [4]. In this section, we show how the final formalism is used through several examples.…”

“…If the model is validated with camera data, it can be used to predict scenes with increased confidence. We have developed physics-based models for passive and active sensors in a software package called Irma [4]. Irma utilizes hemispherical reflectance for the passive sensor.…”

Generation of large scale urban environments to support advanced sensor and seeker simulation

“…1,2,3 The complexity and fidelity requirements of these systems to support very large field of regard sensors has up until now drastically outpaced the capability of scene generation codes and hardware to produce the required signatures. Current state-of-the-art codes used by hundreds of DoD and contractor facilities include Irma (high resolution semi-active radar (SAR), millimeter wave (MMW), VIS, infrared (IR), and laser radar (LADAR)) for high fidelity off line target and background signatures and CHAMP for real-time VIS-IR scene generation.…”

A Ray Tracing Based Model for 3d Ladar Systems

“…At the beginning the purpose was primarily passive IR (infrared) simulations, but now the program also includes radar and ladar simulation capabilities. A number of publications are showing this progress, for instance (Savage, 2006;Savage, 2007;Savage, 2008), where especially (Savage, 2006;Savage, 2007) covers the ladar sensor development.…”