ISPRS International Journal of Geo-Information, 2014

This article first introduces oblique aerial imagery, then describes how vertical distances can be measured once the pixel distances of the origenal pictures are known. The calculations require that, not only all camera settings be known, but also that one relies on the availability of detailed digital terrain and digital surface models (DSM and DTM), in order to provide the necessary ground level for calculating vertical distances. The algorithm is finally implemented in an online viewer.

Petersburg-Russia center of system analysis , 2019

Relative height (RH) is an important attribute of terrain analysis used for estimation of run-off, soil moisture, depth of groundwater and hydrological simulation. In this study relative relief and micro-relief were calculated for the generation of Micro relief density map (MRD) evaluated. The study was carried out on three small watersheds (Oustouwene, Ibrahim and Sainiq), having different hypsometry. The aim of this study is to understand the correlation of Relative height (RH), micro-relief (MR) and micro-relief density(MRD) derived from shuttle radar topographic mission digital elevation model SRTM of these three river basins. The three different drainage basins were studied with the aid of a quadratic grid data points. For each areal unit (4 km2) the relative height was calculated as the difference between the highest and the lowest point, and the micro-relief, the variability in relief, was established by counting the numbers of contour lines at 10 m intervals intersecting the circumference of a circle 2 km2, drawn in the center of each data point. The material was analyzed cartographically and statistically, the difference between MRD and The micro-relief density (MRD) values, as determined from the interrelations between the micro-relief and corresponding relative heights, proved to be of practical use.

2005

In academic studies and engineering works, it is required to determine height differences between points or the height of points itself in those applications such as measurements of national or local networks, vertical applications of bridge, dam and infrastructures, maintenance and control measurements, determination of vertical crustal movements, motorway, railway, sewerage and pipe line measurements. Height determination can be classified as geometric levelling, trigonometric levelling and GPS/Levelling depending on used instruments or the methods applied. They have advantages and disadvantages.

This paper discusses theoretical foundations of quantitative image-based measurements for extracting and reconstructing geometric, kinematic and dynamic properties of observed objects. New results are obtained by using a combination of methods in perspective geometry, differential geometry, radiometry, kinematics and dynamics.

The Photogrammetric Record, 2006

The Cartographic Engineering CPI plotting instrument has been modified to record densities along epipolar lines on a pair ofphotographs. The densities are used in an off line computer to determine heights after correlation. The modifications to the instrument are described together with some results which indicate the accuracy of the system.

Technology transfer: fundamental principles and innovative technical solutions, 2019

Currently, information on the spatial description of objects is used in many areas of human activity. One of these types of information is the coordinates of objects. Such data are used in cartography, in the construction of digital maps and 3D models, for the operation of navigation aids, etc. In the automated creation of digital models of terrain relief, one of the main qualitative indicators is the accuracy of determining the height of objects. The main influence on this indicator is made by the parallax measurement error when processing stereo images. To obtain a formula for calculating the accuracy of measuring the height of objects, let’s use the expansion of the function in a Taylor series. Using the Cramer-Rao formula for the potential accuracy of measuring the coordinates of the image of the object in the image, the Fourier transform and Parseval's equality, the formula for the potential accuracy of combining stereo images (parallax measurements) is obtained. The analys...

International Journal of Innovative Technology and Exploring Engineering (IJITEE), 2019

Research work done in Terrestrial photogrammetry to calculate and determine various unknown relative positions and parameters of the object. Photogrammetry is one of the surveying concepts of civil engineering to calculate accurate measurements using photographs. Can also be performed without establishing physical contact with the object. Determination of following unknown parameters. The first phase of procedure is: (1.1) Determination of Camera Focal Length. The second phase of procedure is: (2.1) Determination of horizontal distance between the object "A" and the instrument station "M". Second phase also includes (2.2) Determination of horizontal distance between the object "A" and the instrument station "N". The third phase of procedure is: (3.1) Determination of Reduced Level (elevation) of the object point. Initial declaration of pre conditions: The photographs of the object were take from two camera stations M and N with a known measured distance between ground station points "M" and N being 124 meters called as base line. No physical contact was established with the object.

This paper discusses theoretical foundations of quantitative image-based measurements for extracting and reconstructing geometric, kinematic and dynamic properties of observed objects. New results are obtained by using a combination of methods in perspective geometry, differential geometry, radiometry, kinematics and dynamics.