GI1.1

Today, the automotive industry is a leading technology driver for lidar systems, because the largest challenge for achieving the next level of vehicle automation is to improve the reliability of the vehicles’ perception system. High costs of mechanically spinning lidars are still a limiting factor, but prices have already dropped significantly during the last decade and are expected to drop by another order of magnitude in the upcoming years thanks to new technologies like micro-electro-mechanical systems (MEMS) based mirrors, optical phased arrays, and vertical-cavity surface-emitting laser (VCSEL) sources. To exploit the potential of these newly emerging cost-effective technologies for geoscientific applications, we developed a novel stand-alone, modular Sensorbox that allows the use of automotive lidar sensors without the necessity of a complete vehicle setup. The novel Sensorbox includes a real-time kinematic differential global positioning system (RTK DGPS) and an inertial measurement unit (IMU) for georeferenced positioning and orientation. This setup enables measuring geoscientific processes and landforms reliably, at any remote location, with very high spatial and temporal resolution, and at relatively low costs. The current setup of the Sensorbox has a 360° field of view with 45° vertical angle, a range of 120m, a spatial resolution of a few cm and a temporal resolution of 20Hz. Compared to terrestrial laser scanners (TLS), such as the Riegl VZ-6000, automotive lidar sensors provide advantages in terms of size (40cm vs. 10cm), weight (20kg vs. 1kg), price (150k€ vs. 10k€), robustness (IP64 vs. IP68), acquisition time/frame rate (1h vs. 20Hz) and eye safety (class 3 vs. class 1). They can therefore provide a very useful complement to currently used TLS systems that have their strengths in range (6000m vs. 100m) and accuracy (1cm vs 5cm) performance. Automotive lidar sensors record high-resolution point clouds with very high acquisition frequencies, resulting in a data stream with order 10^6 points per second. To efficiently work with such large point cloud datasets, the open-source python package ‘pointcloudset’ was developed for handling, analysing, and visualizing large datasets that consists of multiple point clouds recorded over time.

How to cite: Muckenhuber, S., Schlager, B., Gölles, T., Hammer, T., Bauer, C., Exposito Jimenez, V., Schöner, W., Schratter, M., Schrei, B., and Senger, K.: A stand-alone, modular Sensorbox to exploit the potential of automotive lidar for geoscientific applications, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1625, https://doi.org/10.5194/egusphere-egu22-1625, 2022.

The recent development of optical spectroscopy enabled the development of the use of water isotopes in climate, environment and hydrological studies. An increasing number of studies also includes the most recent parameter ¹⁷O-excess as an indicator for kinetic fractionation effects in the water cycle. However, for some applications such as ice core science, the ¹⁷O-excess signal to be measured is very small, of the order of 10 – 20 ppm and it is a big analytical challenge to obtain the requested precision.

Here, we present results of performance of the new express mode and the standard mode developed for d¹⁸O, dD and now also ¹⁷O-excess for a Picarro analyzer. In the standard mode, there is a new injection of water vapor lasting 4.5 minutes every 10 minutes. To get rid of memory effect, the first injections are discarded or a correction is applied which depends on the difference in water isotopic composition between the measured sample and the previous one. For each new sample measured with the express mode, the sequence begins with 6 injections of water vapor in the cavity of 40 secondes each to get rid of the memory effect. It is followed by injections of water vapor lasting 2 minutes every 4 minutes. The advantage of the express mode is to avoid the memory correction and to decrease the measurement time. It thus permits to run more replicates which is important to improve the accuracy of the measurements, especially ¹⁷O-excess. We present here results of several series of samples and standards of different water isotopic composition (d¹⁸O ranging from -54 to 0 ‰) ran three times with both the standard and the express modes and compare the performances of the two modes.  

How to cite: Landais, A., Minster, B., Zuhr, A., Hoffmann, M., and Fourré, E.: Performances of express mode vs standard mode for d18O, dD and 17O-excess with a Picarro analyzer, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4278, https://doi.org/10.5194/egusphere-egu22-4278, 2022.

Seismic monitoring systems are continuously reducing in size and power consumption to facilitate larger scale and more remote experiments.

Güralp have been leading the way to develop a portable, user-friendly broadband seismometer that is robust, omnidirectional in its operation and maintains excellent low-noise performance. The Certimus, released in 2020, incorporates this omnidirectional sensor technology with the Minimus digitizer to provide a proven broadband station. Now, the analogue sensor component has been packaged into a robust and compact stainless-steel housing that is suitable for post-hole and surface deployments, known as the Certis.  

Certis enables users to deploy in dynamic environments, without the need for cement bases or precise levelling, as the sensor will automatically adjust to tilt up to +/- 90 degrees. Due to its small size, low weight and low power consumption, Certis significantly reduces the logistical requirements for broadband posthole deployments. In addition, the lack of levelling required allows for Certis to be easily deployed down hole without the need to manually adjust the sensor’s orientation.

Certis has a wide frequency range of 120s to 100Hz with a remote, user-selectable long period corner. The Certis design is compatible with any commercially available broadband digitizer, however increased functionality is available with the Minimus digitizer, including access to advanced state-of-health parameters.

Güralp has developed a range of accompanying accessories that expand on the functionality of Certis and Certimus. The Portable Power Module offers a compact power solution that can power offline stations for up to 6 weeks. Due to portability of both Certis and Certimus, custom-designed backpacks and smart cases allow for users to easily transport multiple systems into the field. After installation of a buried Certimus, users can easily access data from the microSD card without disturbing the sensor using a Surface Storage Module in line with the GNSS receiver.

How to cite: Mohr, S., Reis, W., Barbara, R., Cilia, M., Watkiss, N., and Hill, P.: The low-power, user-configurable, digital broadband seismometer, analogue iteration: Güralp Certis, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7588, https://doi.org/10.5194/egusphere-egu22-7588, 2022.

Carbon dioxide (CO₂) and methane (CH₄) are the most important greenhouse gases, and there is an increasing need to measure these greenhouse gases with mobile measurement devices. Picarro’s G4301 Cavity Ring-Down Spectroscopy (CRDS) analyzer is a high-performance, light-weight, portable, battery-powered gas concentration analyzer that has enabled real-time measurements of CO₂ and CH₄ in challenging environments in the field of ecosystem [1]–[3], soil science [4] , glaciology [5], limnology [6] and indoor air quality [7]. Here we evaluate the performance of this portable greenhouse gas analyzer for atmospheric measurements, and discuss data obtained with this analyzer during balloon flights.  

The performance of the G4301 analyzer was assessed at the Metrology Laboratory (MLab) that is part of the Atmospheric Thematic Center of ICOS. The MLab regularly tests greenhouse gas analyzers that are used within the European monitoring network ICOS (Integrated Carbon Observation System). We will present CO₂ and CH₄ performance data on the continuous measurement repeatability (CMR), the short-term repeatability (STR), the long-term repeatability (LTR), the ambient temperature sensitivity, the inlet pressure sensitivity, and the built-in water vapor correction. We will discuss these findings in light of measurement requirements for different atmospheric applications.

To assess the performance of the analyzer in mobile field measurements, the G4301 was deployed at several balloon flights over Paris.

References

[1]         J. H. Matthes, A. K. Lang, F. V. Jevon, and S. J. Russell, “Tree stress and mortality from emerald ash borer does not systematically alter short-term soil carbon flux in a mixed northeastern U.S. forest,” Forests, vol. 9, no. 1, pp. 1–16, 2018.

[2]         L. Kohl et al., “Technical note: Interferences of volatile organic compounds (VOCs) on methane concentration measurements,” Biogeosciences, vol. 16, no. 17, pp. 3319–3332, 2019.

[3]         L. Jeffrey et al., “Are methane emissions from mangrove stems a cryptic carbon loss pathway? Insights from a catastrophic forest mortality,” no. June, 2019.

[4]         L. L. Chai et al., “A methane sink in the Central American high elevation páramo: Topographic, soil moisture and vegetation effects,” Geoderma, vol. 362, no. April 2019, p. 114092, 2020.

[5]         J. R. Christiansen and C. J. Jørgensen, “First observation of direct methane emission to the atmosphere from the subglacial domain of the Greenland Ice Sheet,” Sci. Rep., vol. 8, no. 1, p. 16623, Dec. 2018.

[6]         J. A. Villa et al., “Methane and nitrous oxide porewater concentrations and surface fluxes of a regulated river,” Sci. Total Environ., vol. 715, p. 136920, 2020.

[7]         Z. Merrin and P. W. Francisco, “Unburned Methane Emissions from Residential Natural Gas Appliances,” Environ. Sci. Technol., vol. 53, no. 9, pp. 5473–5482, May 2019.

How to cite: Lienhardt, L., Laurent, O., and E. G. Hofmann, M.: Performance assessment of the mobile G4301 Cavity Ring-Down Spectroscopy analyzer for atmospheric CO2, CH4 and H2O measurements, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9283, https://doi.org/10.5194/egusphere-egu22-9283, 2022.

Among new technologies that enable representation of the submarine cultural landscapes, marine geophysical surveys provide fast and cost-effective tools now widely applied to the reconnaissance and management of underwater cultural and natural resources. In addition, passive and active sensors such as LiDAR and optical one mounted on Unmanned Aircraft Systems (UAS)  represent very effective tools for coastal remote sensing applications that require high spatial resolutions. In this work we use ultra-high resolution acoustic and LiDAR-derived data to characterize and map the marine and coastal area in the Baia archeological site (Naples, Italy). This area belongs to the Campi Flegrei volcanic field, which is affected by vertical ground movement called “Bradyseism” that strongly influenced the morphology of the coast over the last 2 Ka. As a consequence, Roman artifacts and structures dating from 1^st Century BC to 4^st Century AC, including Villas, luxury buildings and landing ports are now below the sea water surface, and partly buried within the marine sediments. Marine geophysical investigations included ultra-high resolution swath-bathymetry and parametric sub-bottom profiler surveys that allowed to characterize and map cultural and natural resources at seabed and in the shallow subseafloor. At same time optical (both visible and multispectral) images and LiDAR-derived elevation provided detailed information of the archaeological features and their natural setting along the adjacent coast. The main aim of this approach was to implement non-destructive geophysical methods for investigating and reconstruct the interrelationships between cultural and natural heritage at sea-land interface in the Baia archeological site. Such approach is now crucial for the evaluation of future trends induced by climate change and for a number of policy and management issues.

References

Masini N., Soldovieri F. (Eds) (2017). Sensing the Past. From artifact to historical site. Series: Geotechnologies and the Environment, Vol. 16. Springer International Publishing, ISBN: 978-3-319-50516-9, doi: 10.1007/978-3-319-50518-3, pp. 575

Violante C., Gallocchio E., Pagano F. (2022) Marine archaeological investigation in the submerged Roman site of Baiae using parametric sub-bottom profiler system. Phlegrean Fields Archaeological Park (Naples, Italy). Proceedings of the 2021 IEEE International Conference on Metrology for Archaeology and Cultural Heritage. Journal of Physics Conference Series, in press.

Violante C. (2020) Acoustic remote sensing for seabed archaeology. Proceedings of the International Conference on Metrology for Archaeology and Cultural Heritage. Trento, Italy, October 22-24, 2020, 21-26. ISBN: 978-92-990084-9-2.

Violante C., (2018) A geophysical approach to the fruition and protection of underwater cultural landscapes. Examples from the Bay of Napoli, southern Italy. In: Aveta, A., Marino, B.G., Amore R. (eds.), La Baia di Napoli. Strategie per la conservazione e la fruizione del paesaggio culturale. V. 1, 66-70. Artstudiopaparo, ISBN: 978-88-99130.

How to cite: Violante, C., Masini, N., and Abate, N.: Integrated remote sensing technologies for multi-depth seabed and coastal cultural resources: the case of the submerged Roman site of Baia (Naples, Italy)., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9939, https://doi.org/10.5194/egusphere-egu22-9939, 2022.

Remote sensing technology based on laser scanning (LiDAR) has found a wide range of applications in cave mapping for a high degree of accuracy, level of detail, and time efficiency of this method. Besides the multidisciplinary research, the acquired data representing the cave morphology in a form of a dense point cloud became an essential part of the exploration for understanding the cave speleogenesis alongside capturing the current state that is of great importance in natural and cultural heritage documentation. Traditional cave cartography can benefit from using the LiDAR point clouds by a highly detailed 3D cave model enabling the creation of contours, shaded relief, or geomorphometric parameters, and a practically unlimited number of cross-sections. Compared to the passive remote sensing methods, such as photogrammetry, limited by the light conditions and cave dimensions, laser scanning is an active light-independent method that records additional attributes for each captured point in addition to its 3D coordinates. The recorded intensity of the backscattered laser pulse is very applicable for mapping purposes as it reveals spectral properties of the surface material bringing new aspects not only for the point cloud visualization but also for material differentiation, identification, and spatial localization of the cave paintings. The presented study introduces innovation in the methodology of creating a high-detail cave map from the acquired LiDAR data by combining derived cave floor model and semi-automatic procedure for identification of surface type based on the geomorphometric analysis and recorded intensity. The main benefit of the proposed approach is in the reduction of the author´s subjectivity and cave geometry generalization. By further automatization of this process, maps for large cave systems can be produced in a high level of detail.

How to cite: Nováková, M., Šupinský, J., Kaňuk, J., and Gallay, M.: Semi-automatic production of highly detailed cave maps from LiDAR point clouds, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12392, https://doi.org/10.5194/egusphere-egu22-12392, 2022.