Miracle-dz/UniFAR-FTUs huggingface dataset:
Influence of topography and sensor view angles on NIR/red ratio and greenness vegetation indices of wheat

Abstract Reflectance factors of winter wheat were measured with aground-based radiometer to determine the effect of topography and sensor view angle on the diurnal behaviour of two spectral vegetation indices. Data are presented for fields with 10° slopes in a topographically complex area of central Italy. The ratio of reflectances in near-infrared (NIR) (0.78 to 0.89 μm) to red (0.63 to 0.69 μm) was less sensitive to field aspect than greenness. However, when nadir and off-nadir view angles were compared for the same aspect, greenness displayed less variability. Field aspect and view angle had less effect on both indices when solar zenith angles were small.
Structural Control to the Genesis of Sediment‐hosted Disseminated Jinlongshan Gold Orebelt, China

Abstract. Jinlongshan gold orebelt is a newly discovered sediment‐hosted gold orebelt in Southeastern Qinling Mountains hosted by Late Devonian to Early Carboniferous sedimentary rocks. The location of the belt is regionally controlled by E‐W striking Zhenan‐Banyan and Ningshan Faults, which were formed during the Indo‐Sinian Orogeny. Circular patterns on TM images indicate that intrusive rocks occur at shallow depths in the Jinlongshan orebelt. Two basic types of disseminated and vein‐type mineralization have been recognized. Calcareous siltstone is the most favorable host for disseminated mineralization. Vein‐type mineralization is mostly hosted by limestone. Locally vein‐type mineralization has envelop of disseminated mineralization.
Spatial periodicity in bed form‐scale solute and thermal transport models of the hyporheic zone

Spatially periodic solute boundaries force symmetry across a model domain by ensuring that concentrations and concentration gradients are identical at the same location on opposite boundaries. They have been used in multiple publications on a hyporheic zone model of a single ripple or dune style bed form, including variable density flow and reactive transport variants. We evaluate simulations of multibed form models without imposing spatially periodic transport to demonstrate that nonphysical solute distributions arise from the periodic solute transport assumption. That is, the flow field within the single bed form model leads to a transport scenario that violates the forced symmetry of periodic solute boundary conditions, culminating in a physically unrealistic solute distribution. Our results show that lack of symmetry between boundaries is a function of the vertical concentration gradient and two‐dimensionless parameters characterizing the hyporheic and underflow flow regimes, and the solute exchange between them. We assess the error associated with the spatially periodic assumption based on an analysis of solute fluxes across the lateral bed form model boundaries. While the focus is on steady state concentration distributions, the implications for transient solute transport models are also discussed. We conclude that periodic solute transport boundary conditions should be applied only to bed form models that have minimal vertical dispersive and diffusive solute transfer. This includes gaining systems and tracers such as temperature, for which a temporally periodic flux reversal occurs across the top boundary.
Cloud condensation nuclei in the Amazon Basin: “marine” conditions over a continent?

Cloud condensation nuclei (CCN) are linked to radiative forcing, precipitation, and cloud structure; yet, their role in tropical climates remains largely unknown. CCN concentrations (NCCN) measured during the wet season in the Amazon Basin were surprisingly low (mean NCCN at 1% supersaturation: 267±132 cm−3) and resembled concentrations more typical of marine locations than most continental sites. At low background CCN concentrations, cloud properties are more sensitive to an increase in NCCN. Therefore, enhanced aerosol emissions due to human activity in the Amazon Basin may have a stronger impact on climate than emissions in other continental regions. In spite of the large organic fraction in the Amazonian aerosol, a detailed analysis of number distributions and size‐dependent chemical composition indicates that sulfate plays an important role in CCN activity.
Point scatterers in radar imaging

In ISAR imaging, a Point Scatterer mechanism is frequently invoked, implicitly or explicitly. This paper looks at which categories of EM scattering give rise, in effect, to point scatterer type of return. We find that there are a number of different types of point scattering returns. Such an examination is also relevant to the adequacy of point scatterer models (PSM) which have sometimes been used for modeling aircraft or ships. Another important question is how point scatterers can be recognized as such. Finally the impact of point scatterer assumptions on ISAR autofocus methods will be briefly assessed.
Synergy of multitemporal ERS-1 SAR and Landsat TM data for classification of agricultural crops

The objective of this research was to evaluate the synergistic effects of multitemporal European remote sensing satellite 1 (ERS-1) synthetic aperture radar (SAR) and Landsat thematic mapper (TM) data for crop classification using a per-field artificial neural network (ANN) approach. Eight crop types and conditions were identified: winter wheat, corn (good growth), corn (poor growth), soybeans (good growth), soybeans (poor growth), barley/oats, alfalfa, and pasture. With the per-field approach using a feed-forward ANN, the overall classification accuracy of three-date early- to mid-season SAR data improved almost 20%, and the best classification of a single-date (5 August) SAR image improved the overall accuracy by about 26%, in comparison to a per-pixel maximum-likelihood classifier (MLC). Both single-date and multitemporal SAR data demonstrated their abilities to discriminate certain crops in the early and mid-season; however, these overall classification accuracies (<60%) were not sufficiently high for operational crop inventory and analysis, as the single-parameter, high-incidence-angle ERS-1 SAR system does not provide sufficient differences for eight crop types and conditions. The synergy of TM3, TM4, and TM5 images acquired on 6 August and SAR data acquired on 5 August yielded the best per-field ANN classification of 96.8% (kappa coefficient = 0.96). It represents an 8.3% improvement over TM3, TM4, and TM5 classification alone and a 5% improvement over the per-pixel classification of TM and 5 August SAR data. These results clearly demonstrated that the synergy of TM and SAR data is superior to that of a single sensor and the ANN is more robust than MLC for per-field classification. The second-best classification accuracy of 95.9% was achieved using the combination of TM3, TM4, TM5, and 24 July SAR data. The combination of TM3, TM4, and TM5 images and three-date SAR data, however, only yielded an overall classification accuracy of 93.89% (kappa = 0.93), and the combination of TM3, TM4, TM5, and 15 June SAR data decreased the classification accuracy slightly (88.08%; kappa = 0.86) from that of TM alone. These results indicate that the synergy of satellite SAR and Landsat TM data can produce much better classification accuracy than that of Landsat TM alone only when careful consideration is given to the temporal compatibility of SAR and visible and infrared data.
The impact of debris torrents on substrates of mountain streams/L'impact des laves torrentielles sur le fond alluvial des lits fluviaux en montagne

Resume En region montagneuse, quand des cours d'eau recoivent lateralement des apports sedimentaires issus de laves torrentielles (debris torrent), les tendances normales de leur dynamique peuvent etre modifiees a l'aval. La persistance de ces impacts dans le temps et l'espace dependront des rythmes d'apport des materiaux, de leur volume et de leur dimension aussi bien que de la capacite du cours d'eau a les remobiliser. Le but de ce projet est de decrire et d'expliquer comment le fond alluvial des lits varie en fonction de l'eloignement vers l'aval de la source des debris, dans dix bassins des Coast Range de V Oregon central. Le calibre des materiaux et le fond alluvial du chenal ont ete examines sur 248 coupes transversales, le long de 151 kilometres de cours d'eau. Les bassins different selon la lithologie, la structure geologique, les types de glissement de terrain et leur nombre, et enfin l'impact de l'exploitation forestiere. La tendance au classement des particules autour de cinq centiles (D5, D16, D50, D84, D95) est fonction de la distance par rapport a la confluence des tributaires apportant leur charge torrentielle, les valeurs des exposants dependant du rythme de fonctionnement des torrents, du calibre des sediments a remobiliser et de l'estimation de la puissance a pleins bords. Les resultats mettent en evidence l'impact de la coupe-a- blanc des forets sur le declenchement des laves torrentielles.
May 5, 1998, debris flows in circum-Vesuvian areas (southern Italy): Insights for hazard assessment

On May 5, 1998, after 30 h of continuous rainfall (100–180 mm), large areas of the tephra-rich colluvial cover 12–18 km east of Vesuvius volcano (Italy) failed, generating a series of debris flows that killed more than 150 people in the Sarno area. Some 37 basins were affected almost simultaneously by this phenomenon. The Sarno disaster shows that air-fall deposits can create debris-flow hazards that may extend for several decades or even centuries after eruptions. In the Sarno area, the affected basins have the following features: (1) a funnel shape, debouching at the base of the hillslope; (2) an integrated drainage network with a central subrectilinear channel; (3) slopes exceeding 25° on average; and (4) a thin (∼0.5–2.0 m) volcanic-rich colluvial cover related to the past ash fallout of Vesuvius. The stratigraphy of downstream alluvial-fan deposits records the repeated occurrence of large debris flows. On the basis of the 1998 case history, we propose an approach to evaluate hazard potential related to similar debris flows for the neighboring Clanio Valley. This approach is mainly based on morphometric data derived from a digital elevation model and is of potential worldwide application.
Measuring soil contact pressure on a solid boundary and quantifying soil arching

The paper presents the design, development, and calibration of a soil contact pressure transducer, based on the null method. Air pressure regulated in a tightly controlled PID loop balances the output of a strain gage bridge bonded to the sensing element. This action maintains the sensing element in an underflected state. The result is that the membrane does not interact with the surrounding soil, and errors due to arching are eliminated. In theory, the air pressure required to keep the sensing element in its undeflected state should be equal to the soil contact pressure applied at the soil boundary interface. Calibration of the sensor reveals that its response is exactly as anticipated. The ratio between the required null pressure and applied soil pressure at the boundary interface is 1:1 and independent of soil type, soil stiffness, and load history. The paper presents calibration of the sensor for two very different sands, each at two significantly different levels of relative density. The sensitivity of the sensor is a function of the control software. In its present version the sensor responds accurately to pressure imbalances of 0.3 kPa.
Responses of Macaque Ganglion Cells and Human Observers to Compound Periodic

We measured responses of macaque retinal ganglion cells to different periodic waveforms (sinusoidal, square, rapid-on and rapid-off sawtooth waveforms) for both luminance and equilumlnant chromatic modulation. We analyzed the responses with a peak-to-trough detector. At low frequencies, on-center and off-center magnocelhdar (MC-) pathway cells showed a ten-fold higher responsivity to the rapid-on and rapid-off sawtooth respectively. Red-on (+L-M) and green-on (+M-L) parvocelhdar (PC-) pathway cells showed a four-fold greater responsivity to rapid red-on and rapid green-on equihuuinant chromatic sawtooth waveforms respectively. At an equivalent retinal eccentricity, we measured psychophysical thresholds for luminance stimuli and chromatic stimuli. We concluded that 1~inance sawtooth sensitivities from psychophysics are consistent with selective detection through MC-pathway on- and off-center channels in the visual system. The differences between the compound periodic waveforms seen in the PC-pathway cell data did not occur in the psychophysics. In a second analysis, cell responses to sinusoidal modulation were used to predict the linear response to square-wave and sawtooth waveforms. PC-pathway cells showed linear temporal behavior over a wide range of contrasts, but MC-pathway cells displayed linear behavior only for low-contrast luminance modulation. Using these linear fits, we implemented a model incorporating central low-pass filtering in the MC- and PC-pathways before the peak-to-trough detector. This model captured better the time scale and relative sensitivity to periodic waveforms found in the psychophysical data.
Lidar observation of gravity and tidal waves in the stratosphere and mesosphere

Lidar measurements of atmospheric density and temperature in the altitude range 30-to 80 km have been performed during the last 2 years from the Observatory of Haute-Provence (latitude 44°N, longitude, 6°E). The potential of this technique for studying the middle atmospheric structure is presented and preliminary results on wave propagation are discussed. It is shown that wave-like structures are observed systematically in this height range. Fourier analysis indicates that most of the energy is transported by waves of vertical wavelengths on the order of 8 to 15 km. The amplitude of the density variations is shown to follow a ρ−l/2 law up to 70 km. The characteristics of the observed density waves suggest that they are caused by a superposition of internal gravity waves propagating upward from the troposphere and a diurnal tide component in the range 30–50 km. Such waves are able to induce quite significant perturbations in atmospheric density and therefore temperature on an hourly basis. The Lidar technique is able to monitor those variations for the first time from a ground station operating continuously.
Towards a strategy to implement the Canadian Wetland Inventory using satellite remote sensing

This review describes the context of the Canadian Wetland Inventory (CWI) and then defines the specifications, establishes the most appropriate dataset, and explores the options for its implementation. The CWI is based on the assumption that a consistent map for all areas of Canada using satellite imagery can be produced for a minimum mapping unit of 1 ha. The CWI will establish the state of land cover for wetlands around year 2000, and the CWI map will classify wetlands according to the following scheme defined in the Canadian Wetland Classification System: bog, fen, marsh, swamp, and shallow water. It will then be possible to roll the map up into simpler classes (i.e., upland, wetland, open waters, and coastal waters) compatible with other map products. A wide array of datasets is available, and their potential use in the context of the CWI is explored. The best options regarding the mapping method and the evaluation of the map products are both described, keeping in mind that the most suitable method must strike a balance between methodological advances and practical considerations. This review places the various limitations associated with the CWI in perspective and supports several of the CWI specifications; it should also facilitate selection of a strategy tailored to its implementation, in particular for the classification method and the evaluation of the map.
The Mbale meteorite shower

On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 x 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.19 and 27.4 kg. Short-lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data interpreted as to indicate that the meteorite had an initial mass between 400-1000 kg (most likely approximately 1000 kg) and approached Mbale from AZ = 185 +/- 15, H = 55 +/- 15, and V(sub infinity) = 13.5 +/- 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10-14 km. An estimated 190 +/- 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.
Influence of summertime mesoscale convective systems on the heat balance and surface mixed layer dynamics of a large Amazonian hydroelectric reservoir

We evaluated the impacts of summertime mesoscale convective systems (MCS) on the heat balance and diel surface mixed layer (SML) dynamics of the Brazilian Amazon's Tucurui Hydroelectric Reservoir (THR). We used a synergistic approach that combines in situ data, remote sensing data, and three-dimensional (3-D) modeling to investigate the typical behavior of the components of the heat balance and the SML dynamics. During the study period (the austral summer of 2012–2013), 22 days with MCS activity were identified. These events occurred approximately every 4 days, and they were most frequent during January (50% of the observations). An analysis of local meteorological data showed that when MCS occur, the environmental conditions at THR change significantly (p-value < 0.01). The net longwave flux, which was the heat balance component most strongly impacted by MCS, increased more than 32% on days with MCS activity. The daily integrated heat balance became negative (−54 W m−2) on MCS days, while the balance was positive (19 W m−2) on non-MCS days. In response to the changes in the heat balance, the SML dynamics changed when a MCS was over the THR. The SML depth was typically 28% higher on the days with MCS (∼1.6 m) compared with the days without MCS (∼1.3 m). The results indicate that MCS are one of the main meteorological disturbances driving the heat balance and the mixing dynamics of Amazonian hydroelectric reservoirs during the summer. These events may have implications for the water quality and greenhouse gas emissions of Amazonian reservoirs.
Ground Motions versus Geotechnical and Structural Damage in the February 2011 Christchurch Earthquake

The Mw = 6.3 earthquake of February 22 was the strongest seismic event in a series of damaging aftershocks in and around Christchurch after the Darfield earthquake on 4 September 2010. The source of the Darfield earthquake was in a sparsely populated area and thus it caused no loss of life. Serious damage was mainly due to extensive liquefaction. By contrast, the Christchurch earthquake was generated on a fault in close proximity to the city, resulting in a death toll of 181 people. The Canterbury Plains are covered with river gravels that hide any evidence of past fault activity in this region. The newly revealed Greendale fault was therefore completely unknown. Only a portion of it was revealed on the ground surface during the Darfield earthquake. The second fault (the one that ruptured in February 2011) appears to be a continuation of the first, although no fault structure directly connecting the faults has been recognized. There is a debate among seismologists at this point whether this is a different fault from Greendale one or not (NHRP 2011a; NHRP 2011b; Geonet 2011). Due to its magnitude, shallow depth and close proximity to the city, the February earthquake proved particularly destructive for the central business district (CBD) of Christchurch, where buildings suffered extensive damage. Thanks to a dense network of strong ground motion stations, a large number of records have been obtained, which provide valuable information on the event and offer the possibility of relating the extent of damage to actual measurements of ground shaking. Apart from the southern part of the city on the hills and the Lyttelton port area, Christchurch is built on deep estuarine soil, which has been shaped in the last thousands of years by the ever-changing riverbed. Fine sands—the dominant soil type—and the …
Variable Water Application Depths from a Centre Pivot Irrigation Control System

Current commercially available centre pivot (CP), linear-move and other sprinkler irrigation systems are normally capable and manage to apply relatively uniform controlled amounts of water, whereas the need for irrigation may differ between different zones of a particular field due to spatial soil variability. The 2nd span of CP including 15 nozzles was modified for site-specific irrigation using solenoid valves (SV), programmable logic control (PLC) and EIB-Bus communication protocol to evaluate the validation of site-specific irrigation control system and system modification and to examine water application uniformity. The PLC and the SV functioning were (open and close) were able to able to vary the amount of water proportionate to pulsing level and directly proportional to the fraction of time the valve was opened. There were no apparent problems with the pulsing water delivery system as in field tests were conducted. Except for 10 % pulsing level, measured irrigation depths were within 10 % of the target application rate. Error application of irrigation depth under low pulsing level of 10 % was found due to SV closing delay. Neither pulsing level of SV nor system movement speed had a significant effect and discernable impact on overall application uniformity.
Interactions between Soil Type and Tillage Level in a Dryland Situation

Soil physical conditions were measured under conventional, minimum and zero soil disturbance cropping systems. Seedbed differences were small in soils cropped after stubble, but significantly different on light sandy soils cropped after pasture. Soil resistance to penetrometer was significantly higher at 10 cm with direct drilling. Soil porosity, and properties dependent upon it, varied more with tillage level on loamy sand than on clay loam soil. Root distributions and associated soil interactions were measured by means of soil cores. Root growth rate varied with soil texture and with tillage level. Soil water contents were at matric potentials well above - 1.5 MPa at 6 weeks, but root depth in the finer-textured soil was only half that of the loamy sand. Root extension rate was restricted by soil strength rather than water shortage in the early part of the growing period. Direct tillage with a triple disk drill reduced root extension rate at both sites in the early phase. Evidence of a compaction pan on the loamy sand is presented.
Equatorial evening prereversal vertical drift and spread F suppression by disturbance penetration electric fields

This paper presents new evidences on the responses of the evening sector equatorial ionosphere to prompt penetrating (PP) magnetospheric electric fields. In particular we show for the first time that the evening prereversal enhancement in the vertical drift/zonal electric field (PRE) and the consequent spread F (ESF) generation can be totally suppressed by penetration electric field of westward polarity arising from over‐shielding processes. In contrast the undershielding PP electric field of eastward polarity is found to enhance the PRE and ESF in agreement with recent findings. These results are evaluated using collisional interchange instability growth rate model calculations.