Breault Research Organization Research Articles

Scatter studies for visible emission line coronagraph on board ADITYA-L1 mission

Visible emission line coronagraph (VELC) on board ADITYA-L1 mission is an internally occulted mirror coronagraph designed for solar coronal observations over a field of view (FOV) of 1.05 R o to 3 R o . To achieve the proposed science goals, instrument background should be less than 5 ppm over the FOV of VELC. Major contributor toward instrument background is scatter from surface microroughness and particulate contamination over the primary mirror (M1). Hence, a detailed study of scatter through simulations is carried out to arrive at the surface microroughness specifications and surface cleanliness level requirements of M1. Estimation of RMS microroughness correction factor due to finite band width of the profilometer is very important while specifying the RMS microroughness of M1. This paper discusses in detail about scatter simulations, results, and analysis. All simulations are carried out using Advanced System Analysis Program, developed by Breault Research Organization.

Herschel out-of-field stray-light characterization

Out-of-field stray-light spots of the Herschel telescope optics relative to the PACS and SPIRE instrument apertures were modeled by ray tracing simulations with the Advanced Systems Analysis Program (ASAP, by Breault Research Organization) prior to launch. The predicted stray-light behaviour was verified by dedicated stray-light calibration observations in-flight. This resulted in a special feature of the Herschel Science Mission Planning Software, marking the sky positions of stray-light spots by the very bright infrared planetary sources Venus, Mars, Jupiter, and Saturn, as well as the Moon, thus avoiding contamination of scientific photometric observations by out-of-field stray-light of these sources.

Focus on software

Focus on software

The Advanced Human Eye Model (AHEM): A Personal Binocular Eye Modeling System Inclusive of Refraction, Diffraction, and Scatter

To present a commercially available software tool for creating eye models to assist the development of ophthalmic optics and instrumentation, simulate ailments or surgery-induced changes, explore vision research questions, and provide assistance to clinicians in planning treatment or analyzing clinical outcomes. A commercially available eye modeling system was developed, the Advanced Human Eye Model (AHEM). Two mainstream optical software engines, ZEMAX (ZEMAX Development Corp) and ASAP (Breault Research Organization), were used to construct a similar software eye model and compared. The method of using the AHEM is described and various eye modeling scenarios are created. These scenarios consist of retinal imaging of targets and sources; optimization capability; spectacles, contact lens, and intraocular lens insertion and correction; Zernike surface deformation on the cornea; cataract simulation and scattering; a gradient index lens; a binocular mode; a retinal implant; system import/export; and ray path exploration. Similarity of the two different optical software engines showed validity to the mechanism of the AHEM. Metrics and graphical data are generated from the various modeling scenarios particular to their input specifications. The AHEM is a user-friendly commercially available software tool from Breault Research Organization, which can assist the design of ophthalmic optics and instrumentation, simulate ailments or refractive surgery-induced changes, answer vision research questions, or assist clinicians in planning treatment or analyzing clinical outcomes.

Focus on Software

Focus on Software