Kriging: a method of interpolation for geographical information systems.
ABSTRACT Geographical information systems could be improved by adding procedures for geostatistical spatial analysis to existing facilities. Most traditional methods of interpolation are based on mathematical as distinct from stochastic models of spatial variation. Spatially distributed data behave more like random variables, however, and regionalized variable theory provides a set of stochastic methods for analysing them. Kriging is the method of interpolation deriving from regionalized variable theory. It depends on expressing spatial variation of the property in terms of the variogram, and it minimizes the prediction errors which are themselves estimated. We describe the procedures and the way we link them using standard operating systems. We illustrate them using examples from case studies, one involving the mapping and control of soil salinity in the Jordan Valley of Israel, the other in semi-arid Botswana where the herbaceous cover was estimated and mapped from aerial photographic survey.
- SourceAvailable from: Juan-Pablo Ramirez-Paredes[Show abstract] [Hide abstract]
ABSTRACT: Hyperspectral imagery contains many different frequency bands for each pixel, enabling advanced detection algorithms. The so called pushbroom sensor technology is the most widespread realization of hyperspectral camera. Such cameras capture a single row of pixels, but each pixel can have hundreds of associated frequency bands . Assembling a full image from these pixel rows typically requires having a precise knowledge of the movement of the camera in space while it scans the desired area. In this research we present a procedure to build hyperspectral images from line sensor data without camera position information. The approach relies on an accompanying conventional camera and exploits the homographies between images of planar scenes for image mosaic construction. The hyperspectral camera is geometrically calibrated by using a special target and a variation of the Direct Linear Transform algorithm. This enables mapping the hyperspectral lines to each of the images in the mosaic, and a hyperspectral image can be built using the same homographies computed for the mosaic. Ideally, this research can enable small UAVs to perform enhanced detection and navigation previously reserved for high altitude aircraft.AIAA Infotech@Aerospace (I@A) Conference, Boston, MA; 08/2013
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ABSTRACT: In order to coordinate emergency operations and evacuations, it is vital to accurately assess damage to people, property, and the environment. For decades remote sensing has been used to observe the Earth from air, space and ground based sensors. These sensors collect massive amounts of dynamic and geographically distributed spatiotemporal data every day. However, despite the immense quantity of data available, gaps are often present due to the specific limitations of the sensors or their carrier platforms. This article illustrates how non-authoritative data such as social media, news, tweets, and mobile phone data can be used to fill in these gaps. Two case studies are presented which employ non-authoritative data to fill in the gaps for improved situational awareness during damage assessments and emergency evacuations.11th International Conference ISCRAM Conference; 05/2014
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ABSTRACT: Volume estimation packages often lack tools for measuring and an-alyzing the effect of input data uncertainty and possible error propagation in the volume estimation process. This paper proposes and develops an empirical proce-dure for error modeling in volume estimation using spatial simulation techniques. The procedure can be used to study the stability of interpolation methods in the presence of error, in other words finding a method that predicts best surface fit and volume estimates from imperfect data. The Monte Carlo simulation technique is used to construct an effective algorithm to study the effect of input data uncertainty on volumes estimated with perturbed Kriged surfaces and triangulated surfaces. The results are compared for consistency with a volume generated from a trian-gulated surface that holds the location points fixed.Journal of Surveying Engineering 05/2001; 127(2). · 0.91 Impact Factor