Dynamic range

About: Dynamic range is a research topic. Over the lifetime, 7576 publications have been published within this topic receiving 101739 citations. The topic is also known as: DNR & DR.

Dynamic range and switching speed limitations of an N/spl times/N optical packet switch based on low-gain semiconductor optical amplifiers

Abstract: Two important system performance limitations-dynamic range and switching speed-of an integrated packet switch fabric based on low-gain semiconductor optical amplifiers (SOA's) have been examined by using cascaded blocks of an SOA model, which includes transient effect, nonlinear pulse distortion effect, and amplified spontaneous emission (ASE) noise. Low-gain SOA's were used to minimize ASE noise considering that no optical filters can be integrated in an SOA-based switch fabric. The system performance with and without a narrowband optical filter at the receiver were both studied. By assuming fixed-wavelength transmitters and no optical filter can be used at the receiving end owing to the unpredictability of arriving packet wavelengths, our simulation results indicate that the dynamic ranges of 4/spl times/4 and 8/spl times/8 SOA-based packet switches at 2.5 Gb/s can only be about 3.2 and 0.8 dB, respectively. However, at 155 Mb/s, even without a receiving-end optical filter, the dynamic range of each switch size can be increased by more than 17 dB as compared to the cases of 2.5 Gb/s. Note that the dynamic ranges were estimated under the conditions of a bit error rate (BER) /spl les/10/sup -9/ and a pulse distortion ratio /spl les/30%. We have also shown that, when an optical filter with a 1 nm bandwidth was used at the receiving end to simulate (1) a circuit-switched condition where the center wavelength of the filter can be adjusted according to the established circuit, or (2) a packet-switched condition where each receiver has a wavelength demultiplexer and a detector array, the dynamic range of 4/spl times/4 and 8/spl times/8 switches can be increased to 16.3 and 14 dB, respectively, at 2.5 Gb/s.

Video Enhancement and Dynamic Range Control of HDR Sequences for Automotive Applications

Abstract: CMOS video cameras with high dynamic range (HDR) output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorithms have been proposed in the literature to reduce the dynamic range of still pictures. Anyway, extending the available methods to video is not straightforward, due to the peculiar nature of video data. We propose an algorithm for both reducing the dynamic range of video sequences and enhancing its appearance, thus improving visual quality and reducing temporal artifacts. We also provide an optimized version of our algorithm for a viable hardware implementation on an FPGA. The feasibility of this implementation is demonstrated by means of a case study.

Validation of High Dynamic Range Imaging to Luminance Measurement

Abstract: High dynamic range imaging is a set of techniques that allows for a far greater dynamic range of exposure than normal digital imaging techniques. The intention is to accurately represent the dynamic range of lighting levels found in real scenes, ranging from direct sunlight to deep shadows. Various software packages have emerged that translate these HDR images into high resolution luminance maps. This paper tests the accuracy of one such package, taking into consideration different Munsell hues, values and chroma. It investigates the impact of different light spectra, spatial frequency, vignetting, and thermal noise on the accuracy of luminance measurements and determines the potential errors.

A Photodiode-Array-Based Near-Infrared Spectrophotometer for the 600–1100 nm Wavelength Region:

Abstract: We describe a silicon photodiode-array (PDA)-based near-infrared spectrophotometer for making molecular absorption/diffuse reflectance measurements in the 600-1100 nm wavelength range. Absorptions in this spectral region arise from both low-lying electronic states and vibrational overtones of CH, NH, and OH functional groups and combination bands. One disadvantage of silicon-based array detectors is their decreasing quantum efficiency at wavelengths longer than 950 nm. For transmission measurements, this can be compensated for by the technique of spectral plane masking, which markedly improves the consistency and overall level of baseline noise as well as the dynamic range. The instrument's performance is evaluated in the areas of spectral resolution, baseline noise, stray light, and dynamic range, and a comparison is made with a state-of-the-art mechanically scanned instrument. In the study, the PDA spectrometer attained a signal-to-noise ratio two times better than that of the commercial instrument with a time efficiency advantage of twelve, while achieving a spectral resolution three times greater. Finally, the application of analyzing caustic brine solutions by rapid-scanning NIR spectroscopy is illustrated.

A 3.3-V CMOS 10.7-MHz sixth-order bandpass /spl Sigma//spl Delta/ modulator with 74-dB dynamic range

Abstract: A 3.3-V bandpass /spl Sigma//spl Delta/ modulator for IF sampling at 10.7 MHz in digital radio applications has been developed. The modulator presents a sixth-order single-loop architecture and features a 74-dB dynamic range in a 2OO-kHz signal bandwidth (FM signal), while for a 9-kHz signal bandwidth (AM signal) the dynamic range is 88 dB. The modulator has been integrated in a standard 0.35-/spl mu/m CMOS technology using switched-capacitor technique and consumes 76 mW from a single 3.3V supply.