One key advantage of the model-based approach for Automatic Target Recognition (ATh) is the wide the range of targets and acquisition scenarios that can be accommodated without algorithm re-training. This accrues from the use of predictive models which can be adjusted to hypothesized scenarios on-line. Approaches which rely on measured signature exemplars as the source of reference data for signature matching are constrained to those scenarios represented in the reference data base. The Moving and Stationary TArget Recognition (MSTAR) program will advance the state-of-the art in model-based ATh by developing, evaluating, and testing algorithm performance against a set of Extended Operating Conditions (EOCs) designed to reflect real-world battlefield scenarios. In addition to full 360 deg target aspect coverage over a range of depression angles, the EOCs include variations in squint angle, target articulation and configurations, obscuration due to occlusion and/or layover, and intra-class target variability [l]. These conditions can have a profound impact on the nature of the target signature, necessitating the development of explicit prediction and reasoning algorithms to provide robust target recognition. This paper provides a tutorial description ofthe impact ofthe MSTAR EOCs on SAR target signatures. A brief background discussion of the SAR imaging process is presented first. This is followed by a description of the impact of each EOC category on the target signature along with synthetic imagery examples to illustrate this impact.A key advantage of the MSTAR Model-Based Vision (MBV) paradigm is its flexibility to accommodate widely varying scenarios without algorithm re-training. The MSTAR program will demonstrate this advantage by designing and testing the MBV algorithm against measured data over a broad range of challenging real world battlefield scenarios. These Extended Operating Conditions (EOCs) represent conditions for which ATh algorithms to date have not been developed and tested. They are key drivers in the fundamental design of the MSTAR MBV algorithm [1]. 228/SPIEVOI. 2757 O-8194-2138-3/96/$6.OO Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/21/2015 Terms of Use: http://spiedl.org/terms

No abstract

No abstract

No abstract

Abstract. We are in the process of constructing a high resolution, high signal to noise ratio (SNR) dynamic MRI dataset for the human heart using methodology similar to that employed to construct a low-noise standard brain at the Montreal Neurological Institute. Several high resolution, low SNR magnetic resonance images of 20 phases over the cardiac cycle were acquired from a single subject. Images from identical phases and temporally adjacent phases were registered, and the image intensities were averaged together to generate a high resolution, high SNR dynamic magnetic resonance image volume of the human heart. Although this work is still preliminary, and the results still demonstrate residual artifacts due to motion an sub-optimal alignment of interleaved image slices, our model has a SNR that is improved by a factor of 2.7 over a single volume, spatial resolution of 1.5 mm 3 , and a temporal resolution of 60 ms.

No abstract

Abstract. Anesthetic nerve blocks are a common therapy performed in hospitals around the world to alleviate acute and chronic pain. Tracking systems have shown considerable promise in other forms of therapy, but little has been done to apply this technology in the field of anesthesia. We are developing a guidance system for combining tracked needles with non-invasive ultrasound (US) and patient-specific geometric models. In experiments with phantoms two augmented reality (AR) guidance systems were compared to the exclusive use of US for lumbar facet injection therapy. Anesthetists and anesthesia residents were able to place needles within 0.57mm of the intended targets using our AR systems compared to 5.77mm using US alone. A preliminary cadaver study demonstrated the system was able to accurately place radio opaque dye on targets. The combination of real time US with tracked tools and AR guidance has the potential to replace CT and fluoroscopic guidance, thus reducing radiation dose to patients and clinicians, as well as reducing health care costs.

We evaluated the optical performance of an IR echelle grating produced on a silicon wafer with anisotropic etching techniques. We measured the diffraction efficiency of a sample with a 55° blaze angle and 25-µm groove spacing. We also calculated the efficiency for typical triangular and trapezoidal groove profiles of etched gratings. The diffraction efficiency for unpolarized light can be approximately as high as the efficiency of right-angle groove gratings. The great potential of the etched silicon grating lies in its ease of fabrication, its excellent surface quality, and the high reproducibility of the production process. Compact high-resolution diffraction gratings can be produced by etching the grating pattern into the rear side of a transparent prism. When used in internal reflection, this increases the resolving power of the grating by a factor equal to the refractive index of the prism over a front surface grating of the same length.