7,264 research outputs found

    A model-based approach to correcting spectral irradiance data using an upward-looking airborne sensor (CASI ILS)

    No full text
    A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction. Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods. The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions and represent atmospheric transmission and the proportion of direct:diffuse flux. The method was used to correct CASI ILS data acquired over a site in southern England. Comparison with spectral irradiance measured simultaneously on the ground shows that the method reduced the variability of the ILS data and also compensated for the effect of different flight directions. The sky radiance distribution at sensor level is also calculated by the model, and shows the characteristics of the sky conditions at the time of each flight

    Retrieval of at-sensor irradiance using Incident Light Sensor (ILS)

    No full text
    A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction. Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods. The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions, i.e. clearness index and diffuse ratio. The ILS data corrected by the model are wellmatched to variations of irradiance measured at ground level during three flights. The radiance distribution at sensor level is also calculated by the model, and shows the characteristics of the sky conditions at the time of each flight

    Market Performance of Selected Pulses in Myanmar

    Get PDF
    This paper shows to investigate the performance and efficiency of marketing system of chick pea, green gram and pigeon pea in each selected townships. This study assessed the marketing channel, distributed marketing margins and spatial market price integration to evaluate the performance of pulses marketing in Myanmar. The result showed that producer received the largest net margin followed by the exporter, town wholesaler, wholesaler in Bayintnaung market and finally by the primary collector, pigeon pea marketing channel for Myittha contained primary collector, town wholesaler, Myingyan town wholesaler, Yangon and Mandalay wholesaler and exporter. MAPT also served as intermediate is for export. In this channel, the largest share of net margin kept by producers while the exporter had the share. However, wholesaler in Bayintnaung market, town wholesaler and primary collector reaped small amount of net margin. Among the all intermediateries, the exporters margin was highest for these selected pulses although the other margins were reasonable. The marketing inefficiency exists at the exporters level. It can be concluded that the lower marketing margin is the indicator of competitive and efficient market. The analysis of the two markets integration was to know the degree of co-movement of prices in spatially separated market. The assumption was that Mandalay current wholesale price depend upon the Yangon current wholesale price and taking one to five lags weekly wholesale price of both Yangon and Mandalay markets. The percentages of cointegrated can be seen 57% for chick pea, 65% for green gram and 85% for pigeon pea. It can be concluded that there exist the long-run co-integration for pigeon pea price correlation and moderately co-integration for both chick pea and green gram within the Yangon and Mandalay markets.Myanmar pulses market, market integration, marketing margin, marketing channel, Agribusiness, Marketing,

    Non-thermal WIMP baryogenesis

    Full text link
    We propose a WIMP baryogensis achieved by the annihilation of non-thermally produced WIMPs from decay of heavy particles, which can result in low reheating temerature. Dark matter (DM) can be produced non-thermally during a reheating period created by the decay of long-lived heavy particle, and subsequently re-annihilate to lighter particles even after the thermal freeze-out. The re-annihilation of DM provides the observed baryon asymmetry as well as the correct relic density of DM. We investigate how wahout effects can affect the generation of the baryon asymmetry and study a model suppressing them. In this scenario, we find that DM can be heavy enough and its annihilation cross section can also be larger than that adopted in the usual thermal WIMP baryogenesis.Comment: 5 pages, 6 figure

    Quantum-based Mechanical Force Realization in Pico-Newton Range

    Full text link
    We propose mechanical force realization based on flux quantization in the pico-Newton range. By controlling the number of flux quantum in a superconducting annulus, a force can be created as integer multiples of a constant step. For a 50 nm-thick Nb annulus with the inner and outer radii of 5 μ\mum and 10 μ\mum, respectively, and the field gradient of 10 T/m the force step is estimated to be 184 fN. The stability against thermal fluctuations is also addressed.Comment: 5 pages; 4 figure

    Dissemination of Japanese swordsmanship to Korea

    Get PDF

    Light Intensity Fluctuations and Blueshift

    Get PDF
    • …
    corecore