By the early 1900s, concerns were expressed by ranchers, academicians, and federal scientists that widespread overgrazing and invasion of native grassland by woody shrubs were having severe negative impacts upon normal grazing practices in Western America. Ranchers wanted to reverse these trends and continue their way of life and were willing to work with scientists to achieve these goals. One response to this desire was establishment of the USDA Jornada Experimental Range (783 km²) in south central New Mexico by a Presidential Executive Order in 1912 for conducting rangeland investigations. This cooperative effort involved experiments to understand principles of proper management and the processes causing the woody shrub invasion as well as to identify treatments to eradicate shrubs. By the late 1940s, it was apparent that combining the historical ground-based data accumulated at Jornada Experimental Range with rapidly expanding post World War II technologies would yield a better understanding of the driving processes in these arid and semiarid ecosystems which could then lead to improved rangeland management practices. One specific technology was the use of aerial photography to interpret landscape resource conditions. The assembly and utilization of long-term historical aerial photography data sets has occurred over the last half century. More recently, Global Positioning System (GPS) techniques have been used in a myriad of scientific endeavors including efforts to accurately locate historical and contemporary treatment plots and to track research animals including livestock and wildlife. As an incredible amount of both spatial and temporal data became available, Geographic Information Systems have been exploited to display various layers of data over the same locations. Subsequent analyses of these data layers have begun to yield new insights. The most recent technological development has been the deployment of Unmanned Aerial Vehicles (UAVs) that afford the opportunity to obtain high (5 cm) resolution data now required for rangeland monitoring. The Jornada team is now a leader in civil UAV applications in the USA. The scientific advances at the Jornada in fields such as remote sensing can be traced to the original Western America ranching culture that established the Jornada in 1912 and which persists as an important influence in shaping research directions today. Full article

The importance of landscape and heritage recording and documentation with optical remote sensing sensors is well recognized at international level. The continuous development of new sensors, data capture methodologies and multi-resolution 3D representations, contributes significantly to the digital 3D documentation, mapping, conservation and representation of landscapes and heritages and to the growth of research in this field. This article reviews the actual optical 3D measurement sensors and 3D modeling techniques, with their limitations and potentialities, requirements and specifications. Examples of 3D surveying and modeling of heritage sites and objects are also shown throughout the paper. Full article

At present, most of the digital data acquisition methods generate Digital Surface Model (DSM) and not a Digital Elevation Model (DEM). Conversion from DSM to DEM still has some drawbacks, especially the removing of off terrain point clouds and subsequently the generation of DEM within these spaces even though the methods are automated. In this paper it was intended to overcome this issue by attempting to project off terrain point clouds to the terrain in forest areas using Artificial Neural Networks (ANN) instead of removing them and then filling gaps by interpolation. Five sites were tested and accuracies assessed. They all give almost the same results. In conclusion, the ANN has ability to obtain the DEM by projecting the DSM point clouds and greater accuracies of DEMs were obtained. If the size of the hollow areas resulting from the removal of DSM point clouds are larger the accuracies are reduced. Full article

With the appearance of low-cost and high-resolution consumer-grade digital cameras, a practical three-dimensional (3D) measurement system using a consumer-grade digital camera is greatly anticipated in various fields. In these circumstances, the authors have been concentrating on developing a practical 3D measurement system that includes photogrammetric software called the Image Based Integrated Measurement (IBIM) system. The IBIM system device consists of full/half-mirrors, a consumer-grade digital camera, and a laser distance meter. The most remarkable advantage of the system is its ability to calculate exterior orientation parameters, interior orientation parameters, and pseudo ground control points (GCPs) without using scale bars or the GCPs in the object field. The system has the ability to calibrate multiple cameras of different resolutions using a camera-variant parameter set. However, there remains one issue that needs to be resolved before this system can be effectively used, namely, improvement of the system which does not depend on the IBIM system device. With this motive, a practical photogrammetry method using a consumer-grade digital cameras and a hand-held laser distance meter is proposed. To test our proposed method, the bundle of distances from the center camera position to the feature points in the object field were measured individually at archaeological sites in Greece. In order to evaluate the possibility and practicability of the proposed photogrammetry method, this paper describes and evaluates the camera calibration techniques using images from multiple cameras of different resolutions and a bundle of distances. Full article

Remote sensing has become the most important data source for the digital elevation model (DEM) generation. DEM analyses can be applied in various fields and many of them require appropriate DEM visualization support. Analytical hill-shading is the most frequently used relief visualization technique. Although widely accepted, this method has two major drawbacks: identifying details in deep shades and inability to properly represent linear features lying parallel to the light beam. Several authors have tried to overcome these limitations by changing the position of the light source or by filtering. This paper proposes a new relief visualization technique based on diffuse, rather than direct, illumination. It utilizes the sky-view factor—a parameter corresponding to the portion of visible sky limited by relief. Sky-view factor can be used as a general relief visualization technique to show relief characteristics. In particular, we show that this visualization is a very useful tool in archaeology as it improves the recognition of small scale features from high resolution DEMs. Full article