High-precision topographical methodology for determining height differences when crossing impassable areas

Bitelli, Gabriele; Roncari, G.; Tini, Maria Alessandra; Vittuari, Luca

doi:10.1016/j.measurement.2018.01.013

Cited by 6 publications

(5 citation statements)

References 12 publications

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“…The initial water level measurement and calculation methods for rockfill dams and arch dams are the same as those for gravity dams. According to the known station elevation and trigonometric levelling principle [34], the current reservoir water level elevation can be calculated:…”

Section: Initial Water Level Measurementmentioning

confidence: 99%

Water level measurement for reservoir dams with robotic total station during displacements monitoring

Zhou,

Gao,

Xiao

et al. 2024

Eng. Res. Express

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This study proposes a novel method for water level measurement of reservoir dams by utilizing the image sensor of robotic total station rather than requiring a staff gauge during displacements monitoring. The robotic total station is first aimed at the waterline manually and an image is captured by the telescope coaxial camera to obtain the initial elevation and waterline equation. In the periodic measurement stage, the zenith angle of the telescope is adjusted according to the predicted result to take pictures, and the waterline is extracted based on the parameters of the initial waterline equation through image processing technologies. The waterline is verified, and the water level elevation is estimated then. Simulation and field test results show that waterline extraction error affects the accuracy of the proposed method most, and an accuracy of around 2 pixels can be achieved for the waterline extraction method. And a water level measurement result with centimeter-level accuracy at a distance of about 350m can be expected, which has engineering application prospect.

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Section: Initial Water Level Measurementmentioning

confidence: 99%

Water level measurement for reservoir dams with robotic total station during displacements monitoring

Zhou,

Gao,

Xiao

et al. 2024

Eng. Res. Express

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show abstract

“…It is difficult to determine the accuracy of high-precision surveying, because this must be compared to a more accurate benchmark method. The measurement error for state-of-the-art survey devices depends on many factors, including instrument setup, calibration, sun position, temperature elevation gradient, battery level, and most importantly, operator's expertise (Beshr and Abo Elnaga, 2011;Bitelli et al, 2018). The literature contains very few peer-reviewed investigations that test manufacturers' specifications.…”

Section: Relative Positioning Using Traditional Surveyingmentioning

confidence: 99%

“…The literature contains very few peer-reviewed investigations that test manufacturers' specifications. However, one assessment has illustrated that digital levelling can reach an accuracy of 2 mm/km with precision of 1 mm + 1 mm/km, respectively (Bitelli et al, 2018). Leap-frogging using 150 m distance steps found an elevation precision of 1.9 mm / √ km (Ceylan and Baykal, 2006).…”

Section: Relative Positioning Using Traditional Surveyingmentioning

confidence: 99%

Error in hydraulic head and gradient time-series measurements: a quantitative appraisal

Rau¹,

Post²,

Shanafield³

et al. 2019

Preprint

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Abstract. Hydraulic head and gradient measurements underpin practically all investigations in hydro(geo)logy. There is sufficient information in the literature to suggest that head measurement errors may be so large that flow directions can not be inferred reliably, and that their magnitude can have as great an effect on the uncertainty of flow rates as the hydraulic conductivity. Yet, educational text books contain limited content regarding measurement techniques and studies rarely report on measurement errors. The objective of our study is to review currently-accepted standard operating procedures in hydrological research and to determine the smallest head gradients that can be resolved. To this aim, we first systematically investigate the systematic and random measurements errors involved in collecting time series information on hydraulic head at a given location: (1) geospatial position, (2) point of head, (3) depth to water, and (4) water level time series. Then, by propagating the random errors, we find that with current standard practice, horizontal head gradients

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“…This section briefly summarises both. More details on surveying can be found in Brinker (1995) and on satellite system technology and applications in Hegarty (2017), Bock and Melgar (2016), and Misra and Enge (2010).…”

Section: Clarification Of Error Terminologymentioning

confidence: 99%

“…A catalogue of 3-D positions is given by the International Terrestrial Reference Frame (ITRF). This falls to within ±1 m of the 1984 (WGS84) and is therefore used as the common reference frame for geo-positioning (Bock and Melgar, 2016). The International Hydrographic Organization mandates the use of WGS84 as the horizontal reference for hydrographic mapping (Rizos, 2017).…”

Section: Navigation Satellite Positioningmentioning

confidence: 99%

Error in hydraulic head and gradient time-series measurements: a quantitative appraisal

Rau

Post

Shanafield

et al. 2019

Hydrol. Earth Syst. Sci.

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Abstract. Hydraulic head and gradient measurements underpin practically all investigations in hydrogeology. There is sufficient information in the literature to suggest that head measurement errors can impede the reliable detection of flow directions and significantly increase the uncertainty of groundwater flow rate calculations. Yet educational textbooks contain limited content regarding measurement techniques, and studies rarely report on measurement errors. The objective of our study is to review currently accepted standard operating procedures in hydrological research and to determine the smallest head gradients that can be resolved. To this aim, we first systematically investigate the systematic and random measurement errors involved in collecting time-series information on hydraulic head at a given location: (1) geospatial position, (2) point of head, (3) depth to water, and (4) water level time series. Then, by propagating the random errors, we find that with current standard practice, horizontal head gradients <10-4 are resolvable at distances ⪆170 m. Further, it takes extraordinary effort to measure hydraulic head gradients <10-3 over distances <10 m. In reality, accuracy will be worse than our theoretical estimates because of the many possible systematic errors. Regional flow on a scale of kilometres or more can be inferred with current best-practice methods, but processes such as vertical flow within an aquifer cannot be determined until more accurate and precise measurement methods are developed. Finally, we offer a concise set of recommendations for water level, hydraulic head and gradient time-series measurements. We anticipate that our work contributes to progressing the quality of head time-series data in the hydrogeological sciences and provides a starting point for the development of universal measurement protocols for water level data collection.

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High-precision topographical methodology for determining height differences when crossing impassable areas

Cited by 6 publications

References 12 publications

Water level measurement for reservoir dams with robotic total station during displacements monitoring

Water level measurement for reservoir dams with robotic total station during displacements monitoring

Error in hydraulic head and gradient time-series measurements: a quantitative appraisal

Error in hydraulic head and gradient time-series measurements: a quantitative appraisal

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