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This volume collects the paper presented at the 13th International Workshop on Advanced Infrared Technology and Applications, organized by the Fondazione "Giorgio Ronchi", the Istituto di Fisica Applicata "Nello Carrara" (CNR-IFAC), the Istituto per le Tecnologie delle Costruzioni (CNR-ITC), the Istituto di Scienza e Tecnologie dell'Informazione "Alessandro Faedo" (CNR-ISTI). The workshop was held in Pisa from 29 September to 2 October 2015.

The High Resolution Dynamics Limb Sounder (HIRDLS) instrument was launched oil the NASA Aura satellite in July 2004. HIRDLS is a joint project between the UK and USA, and is a mid-infrared limb emission sounder designed to measure the concentrations of trace species, Cloud and aerosol, and temperature and pressure variations in the Earth’s atmosphere front the upper troposphere to the mesophere. The instrument is intended to make measurements at both high vertical and horizontal spatial resolutions, but validating those measurements is difficult because few other measurements provide that vertical resolution sufficiently closely in time. However, the FOPMOSAT-3/COSMIC suite of radio occultation satellites that exploit the U.S. GPS transmitters to obtain high resolution (similar to 1 km) temperature profiles in the stratosphere does provide sufficient profiles nearly coincident with those from HIRDLS. Comparisons show a good degree intercorrelation between COSMIC and HIRDLS down to about 2 km resolution, with similar amplitudes for each, implying that HIRDLS and COSMIC are able to measure the same small scale features. The optical blockage that occurred within HIRDLS during launch does not seem to have affected this capability.

We address the topic of selectively probing turbid media, equivalent to biological tissue, with ballistic photons. The samples considered exhibit highly forward-directed scattering (anisotropy factor g > 0.9). We propose the utilization of a non-linear grating-based angular filter to separate the faint ballistic signal from optical noise. The filter is conformed of a monochromatic source incident on a ruled grating, positioned at grazing diffraction, followed by a narrow slit. Minute deviations in propagation angle of scattered radiation are amplified non-linearly. A rotation scheme with 1 arc min resolution may provide angular amplifications in the range of 15X-60X. In addition, similar values of transversal beam size reduction enable efficient ~100X-1000X filtering of optical noise. We utilize random walk Monte Carlo calculations to emulate the interactions between radiation and turbid media. The influence of the filter is considered by employing ray trace analysis and conical diffraction theory of ruled gratings. For samples with g =0.995, the configuration permits a significant ~10e3 reduction of optical noise.