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  • Adaptation
  • Climate change
  • GPS
  • ddc:551
  • Springer  (18)
  • Springer Berlin Heidelberg
  • 2000-2004  (18)
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Keywords
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Year
  • 1
    Electronic Resource
    Electronic Resource
    Evidence of response of vegetation to environmental change on high-elevation sites in the Swiss Alps (2000)
    Springer
    Regional environmental change 1 (2000), S. 70-77 
    Details
    ISSN: 1436-378X
    Keywords: Key words Mountain vegetation ; Climate change ; Schynige Platte ; Switzerland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Climate change has in the past led to shifts in vegetation patterns; in a future, warmer climate due to enhanced greenhouse-gas concentrations, vegetation is also likely to be highly responsive to such warming. Mountain regions are considered to be particularly sensitive to such changes. In this paper we present an approach to assess the impact of climate change on long-term vegetation plots at the high-elevation site of the Schynige Platte, 2000 m above sea level, in the Bernese Alps (Switzerland). Records of vegetation spanning the period from 1928 to today at two different sites, each with several plots, were considered. The observed change in the species composition was then related to changes in land use and climate. We used daily values of temperature, snow and precipitation from several high-elevation weather stations to conduct these analyses. The correlation between climate and vegetation patterns revealed that species that prefer low thermal conditions move out of the plots, i.e., their frequency of occurrence is negatively correlated with the average number of degree-days over the last six decades. On the other hand, species with higher thermal demands are seen to be invading the plots, i.e., their frequency of occurrence is positively correlated to the average number of degree-days. Nutrient changes – though independent from climate – also play an important role in the observed shifts in species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00011535
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  • 2
    Electronic Resource
    Electronic Resource
    Bacillus sp. WW3-SN6, a novel facultatively alkaliphilic bacterium isolated from the washwaters of edible olives (2000)
    Springer
    Extremophiles 4 (2000), S. 201-208 
    Details
    ISSN: 1433-4909
    Keywords: Key words Olive wastes ; Bacillus ; Alkaliphile ; Growth characteristics ; Lipid composition ; Phylogeny ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A novel Gram-positive facultatively alkaliphilic, sporulating, rod-shaped bacterium, designated as WW3-SN6, has been isolated from the alkaline washwaters derived from the preparation of edible olives. The bacterium is nonmotile, and flagella are not observed. It is oxidase positive and catalase negative. The facultative alkaliphile grows from pH 7.0 to 10.5, with a broad optimum from pH 8.0 to 9.0. It could grow in up to 15% (w/v) NaCl, and over the temperature range from 4° to 37°C, with an optimum between 27° and 32°C: therefore, it is both halotolerant and psychrotolerant. The bacterium is sensitive to a range of β-lactam, sulfonamide, and aminoglycoside antibiotics, but resistant to trimethoprim. The range of amino acids, sugars, and polyols utilized as growth substrates indicates that this alkaliphile is a heterotrophic bacterium. d(+)-glucose, d(+)-glucose-6-phosphate, d(+)-cellobiose, starch, or sucrose are the substrates best utilized. The major membrane lipids are phosphatidylglycerol and diphosphatidylglycerol, with smaller amounts of phosphatidylethanolamine and an unknown phospholipid. During growth at high pH, the proportion of phosphatidylglycerol is increased relative to phosphatidylethanolamine. The fatty acyl components in the membrane phospholipids are mainly branched chain, with 13-methyl tetradecanoic and 12-methyl tetradecanoic acids as the predominant components. The G + C content of the genomic DNA is 41.1 ± 1.0 mol%. The results of 16S ribosomal RNA sequence analysis place this alkaliphilic bacterium in a cluster, together with an unnamed alkaliphilic Bacillus species (98.2% similarity).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010712
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  • 3
    Electronic Resource
    Electronic Resource
    An examination of the relationship between flowering times and temperature at the national scale using long-term phenological records from the UK (2000)
    Springer
    International journal of biometeorology 44 (2000), S. 82-87 
    Details
    ISSN: 1432-1254
    Keywords: Key words Flowering ; Phenology ; Climate change ; Temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract  This paper examines the mean flowering times of 11 plant species in the British Isles over a 58-year period, and the flowering times of a further 13 (and leafing time of an additional 1) for a reduced period of 20 years. Timings were compared to Central England temperatures and all 25 phenological events were significantly related (P〈0.001 in all but 1 case) to temperature. These findings are discussed in relation to other published work. The conclusions drawn from this work are that timings of spring and summer species will get progressively earlier as the climate warms, but that the lower limit for a flowering date is probably best determined by examining species phenology at the southern limit of their distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004840000049
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  • 4
    Electronic Resource
    Electronic Resource
    Phenology in central Europe – differences and trends of spring phenophases in urban and rural areas (2000)
    Springer
    International journal of biometeorology 44 (2000), S. 60-66 
    Details
    ISSN: 1432-1254
    Keywords: Key words Phenology ; Trends ; Climate change ; Central Europe ; Urban climate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract  In order to examine the impacts of both large-scale and small-scale climate changes (urban climate effect) on the development of plants, long-term observations of four spring phenophases from ten central European regions (Hamburg, Berlin, Cologne, Frankfurt, Munich, Prague, Vienna, Zurich, Basle and Chur) were analysed. The objective of this study was to identify and compare the differences in the starting dates of the pre-spring phenophases, the beginning of flowering of the snowdrop (Galanthus nivalis) and forsythia (Forsythia sp.), and of the full-spring phenophases, the beginning of flowering of the sweet cherry (Prunus avium) and apple (Malus domestica), in urban and rural areas. The results indicate that, despite regional differences, in nearly all cases the species studied flower earlier in urbanised areas than in the corresponding rural areas. The forcing in urban areas was about 4 days for the pre-spring phenophases and about 2 days for the full-spring phenophases. The analysis of trends for the period from 1951 to 1995 showed tendencies towards an earlier flowering in all regions, but only 22% were significant at the 5% level. The trends for the period from 1980 to 1995 were much stronger for all regions and phases: the pre-spring phenophases on average became earlier by 13.9 days/decade in the urban areas and 15.3 days/decade in the rural areas, while the full-spring phenophases were 6.7 days earlier/decade in the urban areas and 9.1 days/decade earlier in the rural areas. Thus rural areas showed a higher trend towards an earlier flowering than did urban areas for the period from 1980 to 1995. However, these trends, especially for the pre-spring phenophases, turned out to be extremely variable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004840000062
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  • 5
    Electronic Resource
    Electronic Resource
    Geographic pattern of genetic variation in photosynthetic capacity and growth in two hardwood species from British Columbia (2000)
    Springer
    Oecologia 123 (2000), S. 168-174 
    Details
    ISSN: 1432-1939
    Keywords: Key words Intraspecific genetic variation ; Photosynthesis ; Frost hardiness ; Climate change ; Growing season
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Geographic patterns of intraspecific variations in traits related to photosynthesis and biomass were examined in two separate common garden experiments using seed collected from 26 Sitka alder (Alnus sinuata Rydb.) and 18 paper birch (Betula papyrifera Marsh.) populations from climatically diverse locations in British Columbia, Canada. Exchange rates of carbon dioxide and water vapour were measured on 2-year-old seedlings to determine the maximum net instantaneous photosynthetic rate, mesophyll conductance, stomatal conductance, and photosynthetic water use efficiency. Height, stem diameter, root and shoot dry mass and fall frost hardiness data were also obtained. Mean population maximum photosynthetic rate ranged from 10.35 to 14.57 µmol CO2 m–2 s–1 in Sitka alder and from 14.76 to 17.55 µmol CO2 m–2 s–1 in paper birch. Based on canonical correlation analyses, populations from locations with colder winters and shorter (but not necessarily cooler) summers had higher maximum photosynthetic rates implying the existence of an inverse relationship between leaf longevity and photosynthetic capacity. Significant canonical variates based on climatic variables derived for the seed collection sites explained 58% and 41% of variation in the rate of photosynthesis in Sitka alder and paper birch, respectively. Since growing season length is reflected in date of frost hardiness development, an intrinsic relationship was found between photosynthetic capacity and the level of fall frost hardiness. The correlation was particularly strong for paper birch (r=–0.77) and less strong for Sitka alder (r=–0.60). Mean population biomass accumulation decreased with increased climate coldness. These patterns may be consequential for evaluation of the impact of climate change and extension of the growing season on plant communities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004420051002
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  • 6
    Electronic Resource
    Electronic Resource
    Photosynthetic responses to CO2 enrichment of four hardwood species in a forest understory (2000)
    Springer
    Oecologia 122 (2000), S. 11-19 
    Details
    ISSN: 1432-1939
    Keywords: Key words Acclimation ; Atmospheric carbon dioxide ; Climate change ; Photosynthesis ; Shade tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We compared the CO2- and light-dependence of photosynthesis of four tree species (Acer rubrum, Carya glabra, Cercis canadensis, Liquidambar styraciflua) growing in the understory of a loblolly pine plantation under ambient or ambient plus 200 µl l–1 CO2. Naturally-established saplings were fumigated with a free-air CO2 enrichment system. Light-saturated photosynthetic rates were 159–190% greater for Ce. canadensis saplings grown and measured under elevated CO2. This species had the greatest CO2 stimulation of photosynthesis. Photosynthetic rates were only 59% greater for A. rubrum saplings under CO2 enrichment and Ca. glabra and L. styraciflua had intermediate responses. Elevated CO2 stimulated light-saturated photosynthesis more than the apparent quantum yield. The maximum rate of carboxylation of ribulose-1,5-bisphosphate carboxylase, estimated from gas-exchange measurements, was not consistently affected by growth in elevated CO2. However, the maximum electron transport rate estimated from gas- exchange measurements and from chlorophyll fluorescence, when averaged across species and dates, was approximately 10% higher for saplings in elevated CO2. The proportionately greater stimulation of light-saturated photosynthesis than the apparent quantum yield and elevated rates of maximum electron transport suggests that saplings growing under elevated CO2 make more efficient use of sunflecks. The stimulation of light-saturated photosynthesis by CO2 did not appear to correlate with shade-tolerance ranking of the individual species. However, the species with the greatest enhancement of photosynthesis, Ce. canadensis and L. styraciflua, also invested the greatest proportion of soluble protein in Rubisco. Environmental and endogenous factors affecting N partitioning may partially explain interspecific variation in the photosynthetic response to elevated CO2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008827
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  • 7
    Electronic Resource
    Electronic Resource
    Natural selection causing microsatellite divergence in wild emmer wheat at the ecologically variable microsite at Ammiad, Israel (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 985-999 
    Details
    ISSN: 1432-2242
    Keywords: Key words Natural selection ; Microecological diversity ; Microsatellites ; Adaptation ; T. dicoccoides ; Wild emmer wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Genetic diversity at 28 microsatellite loci was studied in a natural population of Triticum dicoccoides at the Ammiad microsite, north of the Sea of Galilee, Israel. This microsite was subdivided into four major habitats, North, Valley, Ridge and Karst, and further subdivided into nine subhabitats. The units thus defined showed strong and highly significant differentiation in ecological factors; in particular with respect to cover, proximity and height of rocks, and surface soil moisture after early rains. The results showed that allele distributions at microsatellite loci were nonrandom and associated with habitats. Significant genetic differentiation and variation in repeat number were found among subpopulations in the four major habitats and nine subhabitats. Habitat-specific and -unique alleles and linkage disequilibria were observed in the Karst subpopulation. The subpopulations dwelling in drier habitats and subhabitats showed higher genetic diversities at microsatellite loci. These results suggest that natural selection, presumably through aridity stress, acts upon microsatellite divergence predominantly on noncoding sequences, thereby contributing to differences in fitness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051380
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  • 8
    Electronic Resource
    Electronic Resource
    Application of microsatellites in wheat (Triticum aestivum L.) for studying genetic differentiation caused by selection for adaptation and use (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 242-248 
    Details
    ISSN: 1432-2242
    Keywords: Key words DNA markers ; Genetic diversity ; Agroecological area ; Quality ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  For studying genetic differentiation caused by selection for adaptation and end-use, the allele frequencies of 42 microsatellites (MS), representative of the three wheat genomes, were analysed in a total of 60 wheat cultivars. The cultivars originate from three agroecological areas (AEAs) – Germany, Austria and Hungary – and represent equal numbers of ’quality wheats’ and ’feed wheats’ for each country. For the 42 loci, 202 alleles were detected using PAGE and silver staining. The average number of alleles per locus was 4.8, including four monomorphic loci. For 16 loci, null alleles were detected. Cluster analysis clearly differentiated the varieties according to the three AEAs and, within each AEA, into quality wheats from feed wheats. Analysis of variance revealed highly significant differences of distance data between AEAs as well as between quality groups. The correlation between genetic distance (GD) and pedigree data (coefficient of diversity, COD) was r s=0.45. The results have proven the excellent resolving power of MS in varietal differentiation, which arises through breeding under specific environmental conditions, and for different end-use.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050032
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  • 9
    Electronic Resource
    Electronic Resource
    An approach to GLONASS ambiguity resolution (2000)
    Springer
    Journal of geodesy 74 (2000), S. 421-430 
    Details
    ISSN: 1432-1394
    Keywords: Key words: GLONASS ; GPS ; Ambiguity resolution ; Satellite geodesy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract.  When processing global navigation satellite system (GLONASS) carrier phases, the standard double-differencing (DD) procedure cannot cancel receiver clock terms in the DD phase measurement equations due to the multiple frequencies of the carrier phases. Consequently, a receiver clock parameter has to be set up in the measurement equations in addition to baseline components and DD ambiguities. The resulting normal matrix unfortunately becomes singular. Methods to deal with this problem have been proposed in the literature. However, these methods rely on the use of pseudo-ranges. As pseudo-ranges are contaminated by multi-path and hardware delays, biases in these pseudo-ranges are significant, which may result in unreliable ambiguity resolution. A new approach is addressed that is not sensitive to the biases in the pseudo-ranges. The proposed approach includes such steps as converting the carrier phases to their distances to cancel the receiver clock errors, and searching for the most likely single-differenced (SD) ambiguity. Based on the results from the theoretical investigation, a practical procedure for GLONASS ambiguity resolution is presented. The initial experimental results demonstrate that the proposed approach is useable in cases of GLONASS and combined global positioning system (GPS) and GLONASS positioning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001900000096
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  • 10
    Electronic Resource
    Electronic Resource
    The Shopping Jacket: Wearable computing for the consumer (2000)
    Springer
    Personal and ubiquitous computing 4 (2000), S. 241-244 
    Details
    ISSN: 1617-4917
    Keywords: GPS ; Location sensing ; Pinger ; Shopping jacket ; Wearable computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract As part of the Bristol Wearable Computing Initiative, we are exploring location-sensing systems suitable for use with wearable computing. In this paper we present our findings, and in particular a wearable application — the ‘Shopping Jacket’ — which relies on a minimal infrastructure to be effective. We use two positioning devices, ‘pingers’ and GPS. The pinger is used to signal the presence of a shop, and to indicate the type of shop and its website. The GPS is used to disambiguate which branch of a high street chain is being passed. The wearable uses this information to determine whether the wearer needs to be alerted that they are passing an interesting shop, or to direct the wearer around a shopping mall. The Shopping Jacket integrates a wearable CardPC, GPS and pinger receivers, a near-field radio link, hand-held display, GSM data telephone and a speech interface into a conventional sports blazer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02391567
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  • 11
    Electronic Resource
    Electronic Resource
    Generation of jumping motion pattern for a hopping robot using genetic algorithm (2000)
    Springer
    Artificial life and robotics 4 (2000), S. 31-36 
    Details
    ISSN: 1614-7456
    Keywords: Genetic algorithm ; Hopping robot ; Adaptation ; Pattern generator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper describes an application of genetic algorithm to generate a jumping motion pattern for a hopping robot. A central pattern generator is used to generate the motion pattern. The tuning parameters of the central pattern generator are regarded as genes and adjusted by the genetic algorithm, so that the hopping robot can jump continuously to the reference height with the minimum force. To realize online tuning of the parameters, new genetic operations such as few individuals, quick estimation, instant selection, and intentional mutation are introduced. The experimental results demonstrate the effectiveness of the proposed scheme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02481474
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  • 12
    Electronic Resource
    Electronic Resource
    Gas exchange and water relations of two Rocky Mountain shrub species exposed to a climate change manipulation (2000)
    Springer
    Plant ecology 146 (2000), S. 195-204 
    Details
    ISSN: 1573-5052
    Keywords: Artemisia ; Climate change ; Pentaphylloides ; Photosynthesis ; Rocky Mountains ; Subalpine ; Transpiration ; Water potential ; Water use efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gas exchange and water relations responses to warming were compared for two shrub species, Artemisia tridentata spp. vaseyana (Asteraceae), a widely distributed evergreen species of the Great Basin and the western slope of the Rocky Mountains, and Pentaphylloides floribunda (Rosaceae), a deciduous shrub limited in distribution to moist, high-elevation meadows. Plants were exposed to an in situ infrared (IR) climate change manipulation at the Rocky Mountain Biological Laboratory, near Crested Butte, CO. Measurements of gas exchange and water relations were made on the two species in July and August, 1993 from plants growing in situ in infrared-heated and control plots. Carbon dioxide uptake, water loss, leaf temperature, water use efficiency, and water potential were compared to test the hypothesis that leaf and soil responses to IR will cause leaf level changes in photosynthesis. Photosynthetic CO2 uptake and water use efficiency increased for A. tridentata (2.9 vs. 1.9 μmol m−2 s−1 and 1.2 vs. 0.7 mmol C/mol H2O) in the heated plots compared to the controls, while water potential was significantly lower in the heated plots (−1.1 vs. −0.5 MPa). The heating treatment decreased rates of photosynthesis for P. floribunda, but not significantly so. For A. tridentata, the results are consistent with the community-level changes observed with heating. Taken together, the evidence suggests that global warming is likely to result in increasing dominance of A. tridentata in subalpine meadow habitat now dominated by forbs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009863201751
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  • 13
    Electronic Resource
    Electronic Resource
    Finite Element Simulation of Location- and Time-Dependent Mechanical Behavior of Chondrocytes in Unconfined Compression Tests (2000)
    Springer
    Annals of biomedical engineering 28 (2000), S. 318-330 
    Details
    ISSN: 1573-9686
    Keywords: Biphasic ; Poroelastic ; Cartilage ; Finite element analysis ; Cell mechanics ; Tissue growth ; Adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Experimental evidence suggests that cells are extremely sensitive to their mechanical environment and react directly to mechanical stimuli. At present, it is technically difficult to measure fluid pressure, stress, and strain in cells, and to determine the time-dependent deformation of chondrocytes. For this reason, there are no data in the published literature that show the dynamic behavior of chondrocytes in articular cartilage. Similarly, the dynamic chondrocyte mechanics have not been calculated using theoretical models that account for the influence of cell volumetric fraction on cartilage mechanical properties. In the present investigation, the location- and time-dependent stress-strain state and fluid pressure distribution in chondrocytes in unconfined compression tests were simulated numerically using a finite element method. The technique involved two basic steps: first, cartilage was approximated as a macroscopically homogenized material and the mechanical behavior of cartilage was obtained using the homogenized model; second, the solution of the time-dependent displacements and fluid pressure fields of the homogenized model was used as the time-dependent boundary conditions for a microscopic submodel to obtain average location- and time-dependent mechanical behavior of cells. Cells and extracellular matrix were assumed to be biphasic materials composed of a fluid phase and a hyperelastic solid phase. The hydraulic permeability was assumed to be deformation dependent and the analysis was performed using a finite deformation approach. Numerical tests were made using configurations similar to those of experiments described in the literature. Our simulations show that the mechanical response of chondrocytes to cartilage loading depends on time, fluid boundary conditions, and the locations of the cells within the specimen. The present results are the first to suggest that chondrocyte deformation in a stress-relaxation type test may exceed the imposed system deformation by a factor of 3–4, that chondrocyte deformations are highly dynamic and do not reach a steady state within about 20 min of steady compression (in an unconfined test), and that cell deformations are very much location dependent. © 2000 Biomedical Engineering Society. PAC00: 8719Rr, 8717Aa, 0270Dh
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1114/1.271
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  • 14
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    Combine Harvester Control Using Real Time Kinematic GPS (2000)
    Springer
    Precision agriculture 2 (2000), S. 147-161 
    Details
    ISSN: 1573-1618
    Keywords: GPS ; mobile robot ; robot control ; chained systems ; guidance system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An accurate vehicle guidance system is required for some precision agriculture operations. It can be used for high speed direct seeding on a farm tractor. Such a system also ensures neither overlapping nor missing areas during the harvest, even when visibility is poor. But, automatic path following in the field is a difficult problem. Many vehicle guidance systems have been studied. Some use two dimensional (2D) information, while others are based upon 3D information. Most of the sensors use output information relative to their environment without absolute reference of the path. As the new reference is based on the previous pass, one of the main problems encountered with the edge following systems is an increase in the amplitude of oscillations due to guidance errors in successive passes. Thus, human operators frequently and periodically sacrifice efficiency in one pass to “straighten out” the edge of the worked area. Another kind of sensor, centimeter accuracy Real-Time Kinematic based Global Positioning System (GPS) receivers, can be used. The advent of accurate systems, with a standard deviation from the mean of about 10 mm, allows the design and implementation of absolute vehicle guidance systems. A few approaches to GPS-based control systems also include attitude measurement sensors such as fiber optic gyroscope. The preliminary work presented in this paper was aimed at validating the use of a GPS receiver in a vehicle guidance system, without any orientation sensor. We have designed a controller to perform a line-following task. Real-time experiments have been carried out on a combine harvester.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011473630247
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  • 15
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    Automation and Standardisation of Site Specific Soil Sampling (2000)
    Springer
    Precision agriculture 2 (2000), S. 179-188 
    Details
    ISSN: 1573-1618
    Keywords: soil sampling ; sampler design ; quality control ; standardisation ; GPS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The quality of soil sampling has a significant effect on the accuracy of site specific fertiliser application. Soil sampling depth, number of cores and their distribution within a field or field section are important criteria for achieving a high quality sample. Considering the increased number of soil samples required for site specific fertiliser application, the chosen method of sampling needs to be fast, cost effective and accurate to provide reliable information. Soil sampling systems currently in use do not allow an automatic control of the precise soil sampling depth and the number of cores taken. The system described here uses a newly designed hydraulic auger, that samples the soil at a constant depth under varying field and soil conditions. This has been achieved by a specific shape and angle of the auger turns. The number of cores taken and their depth are controlled automatically by a sensor linked to an on-board computer. Furthermore, diagnostic tools identify errors and prevent any malfunction. The soil sampling system allows a fully automated and standardised sampling procedure, providing the required reliability for site specific fertiliser application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011477731156
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  • 16
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    Evaluation of Sub-Meter and 2 to 5 Meter Accuracy GPS Receivers to Develop Digital Elevation Models (2000)
    Springer
    Precision agriculture 2 (2000), S. 189-200 
    Details
    ISSN: 1573-1618
    Keywords: digital elevation model ; GPS ; topographic maps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The digital elevation model (DEM) is considered by many to be an important base map for a precision farming GIS (Geographic Information System). Previous work has shown that dual-frequency survey grade GPS (Global Positioning System) receivers are capable of rapidly producing accurate positional data from a moving vehicle from which DEM's can be developed. However, this type of GPS receiver is expensive and somewhat difficult to use properly. This paper presents the results of a study to evaluate the potential of using single frequency sub-meter and 2–5 meter horizontal accuracy GPS receivers to enable the farmer to collect multiple passes of GPS data during normal field operations from which DEM's can be developed. The results show that when using a single frequency sub-meter GPS receiver: (1) it is possible to develop a DEM with standard deviation of the elevation accuracy on the order of 0.12–0.14 m, (2) in order to collect data with this level of elevation accuracy, data should only be collected when the GDOP (Geometric Dilution Of Precision) is less than 5.0, (3) at least 10 passes of data with appropriate data averaging is required to produce this level of elevation accuracy. The results also indicate that the vertical error associated with a 2–5 meter horizontal accuracy GPS receiver is such that it is not recommended for use in collecting data to develop DEM's in this application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011429815226
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  • 17
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    Crustal deformation state shown by fault measurement and GPS (2000)
    Springer
    Journal of seismology 4 (2000), S. 259-266 
    Details
    ISSN: 1573-157X
    Keywords: base line ; earthquake risk area ; leveling ; fault deformation ; GPS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In Capital area of China, many faultdeformational surveying sites were set up sequentiallyfrom 1967. With short leveling, short base line andshort ranging net across fault, a lot of data havebeen accumulated. In 1992, GPS (Global PositioningSystem) measurements were started in China. Two timesof GPS measurements have been made in 1992 and 1995respectively. The International Terrestrial ReferenceFrame 93 and the Precision Ephemeris provided byInternational GPS Geodynamics Service (IGS) fromGlobal GPS tracing network solution are used. In GPSanalysis and data processing, GAMIT software and GLOBKsoftware are used. The results from these two kinds ofdata are discussed. For earthquake risk area judgment,it is of interest to know where is compressional areaand where is tensional area, and generally thecompressional areas are considered as risk area andcalled abnormal area. All the data from shortleveling, short ranging (measured bylaser-range-finder), short base line (measured by baseline tape) and GPS methods can give us the descriptionabout the deformational state of the crust –compressional state or tensional state. The comparisonshows that, some of the two kinds of data areconsistent, a few of them are contradictory, and thenthe results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009811317929
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  • 18
    Electronic Resource
    Electronic Resource
    Guidance of a Forage Harvester with GPS (2000)
    Springer
    Precision agriculture 2 (2000), S. 281-291 
    Details
    ISSN: 1573-1618
    Keywords: automatic steering ; GPS ; swath guidance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Precision agriculture requires automatic control of agricultural machinery in order to cope with the large amount of information which has to be applied during site specific field work. The driver is occupied with operating and supervising the controlled and non-controlled implements as well as with vehicle guidance. Steering, in particular, is monotonous and tiring. This can result in reduced operation quality. This was the motivation to develop a concept of a guidance system for agricultural vehicles. A self-propelled forage harvester was the test vehicle for this research. The harvester was equipped with an automatic steering system. Real Time Kinematic Global Positioning System (RTK-GPS) was used as the only positioning sensor due to high absolute accuracy within the field and its high reliability. The system performance was investigated under various test conditions. Additionally a guidance-path-planning for swath harvesting operations was developed. Both the automatically steered forage harvester and the path planner could be examined under real field conditions. The standard deviation of the driving performance was better than 100 mm under all conditions. The swaths could be collected reliably with the automatically steered forage harvester.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011842907397
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