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The country of Libya, situated on the Mediterranean fault zone, has a distinctive geodynamic regime due to the interplay between the Eurasian and African plates, which governs its tectonic evolution. In addition to its seismological significance, Libya is characterized by numerous subsidence and slope instabilities in regions with steep terrain. These geological phenomena have significant consequences for the built environment, as they pose an immediate danger to entire towns and essential infrastructure. Furthermore, infrequent weather phenomena, such as intense precipitation and thunderstorms, when coupled with the geological characteristics of some regions and the presence of seismically active terrain, have the potential to trigger landslide and land subsidence, resulting in significant harm to vital infrastructure. The current study utilizes the DInSAR technology to identify distinct subsidence occurrences that were induced by intense precipitation in coastal regions of Libya, specifically in Derna. These areas experienced significant flooding resulting in collapses during September 2023. A total of six pairs of co-event Interferometric Synthetic Aperture Radar (SAR) were utilized to generate displacement maps in the vertical, north-east, and north-west directions for the purpose of analysing the deformations. The aforementioned activities are conducted via Sentinel-1A images, which is freely accessible through the Copernicus program. Additionally, flood-prone zones were defined using Sentinel-1 GRD imagery. The Interferometric processing revealed multiple areas of subsidence. Subsidence rates of up to −14 cm were found in Derna city's urban cores after flood. The findings suggest that subsidence may have an effect on the flood-proneness of the region of Derna City as Ground subsidence also occurred in the period immediately before the earthquake, at a rate of −14 cm. [ABSTRACT FROM AUTHOR]

This study explores the relationship between Land Use Land Cover (LULC), Land Surface Temperature (LST), and Urban Heat Island (UHI) in Dakahlia Government using Landsat 8 images from 2014 to 2020. Support Vector Machine (SVM) and Mono-Window Algorithm were used to generate LULC and estimate LST. Results reveal an increase in built-up areas, rising LST, and variable UHI thresholds. The study highlights the impact of COVID-19 on LST in 2020. Positive correlations between LST and Normalized difference build-up index (NDBI) and negative correlations with Normalized difference vegetation index (NDVI) were observed. Projections for 2030 suggest an increase in high-temperature areas. [ABSTRACT FROM AUTHOR]

PPP_Mansoura is a new software that can process multi-GNSS data work on MATLAB environment and linked with C# in the preprocessing stage. It gives highly accurate results and provides a results file for each epoch, and the users can choose the GNSS system they want to run with the primary systems (GPS or GLONASS) and all this with simple MATLAB Code. For testing the software, we processed the raw data (RINEX 3) from 17 MGEX stations for 24 h data during 1-week with a 30-s interval time and submitted it to the new software and PPPH software. The averaged positioning errors obtained from PPP_Mansoura and PPPH were 5.14 mm and 6.9 mm respectively, for the East direction, 11.6 mm and 14 mm for the North direction, and 14.56 mm and 20.4 mm respectively for the Up direction, the averaged convergence time obtained from PPP_Mansoura and PPPH were 35.3 min and 54.47 min, so the results show that PPP_Mansoura give results with high accuracy can be comparable with PPP standards results and PPP software results. [ABSTRACT FROM AUTHOR]

Ambiguity resolution (AR) is essential for quick and accurate Global Navigation Satellite System GNSS location and navigation. In addition to location parameters, there are various additional GNSS characteristics that are relevant for a wide range of applications such as instrumental calibrations, atmospheric sounding, and time transfer. We offer differential code bias and satellite geometry for the GNSS estimable parameters using MANS-PPP software backage. In this research, we used the MANS-PPP software package to execute the processing method and generate the PPP GNSS solution. We demonstrated how differential code bias and satellite geometry can effectively enhance initial time and positioning error for multi-GNSS satellites. PPP Processing observation data in static mode was used by the different DCB files the Chinese Academy of Sciences (CAS), the German Aerospace Centre (DLR), and the Centre for Orbit Determination in Europe (CODE), for the 12 stations from IGS, and we analyzed the impact of errors from the satellite geometry. The results illustration that the correction of DCB significantly improves the PPP ambiguity resolution success rate and quality, which have higher DCB values. The satellite geometry also has a substantial influence on the PPP ambiguity resolution, with a better geometry leading to a higher success rate and quality. Furthermore, the use of multiple GNSS constellations and the optimization of the satellite selection and weighting algorithms can further improve the PPP ambiguity resolution and the resulting positioning accuracy. [ABSTRACT FROM AUTHOR]

One of the primary geodetic mapping tasks in the post-processing of GNSS data is precise point positioning (PPP). Research institutions and universities have established software packages and online PPP services in prior years. Still, it is problematic to satisfy the high-rate update criterion of PPP due to the quick growth of GNSS constellations. In PPP GNSS data processing, Square Root Information Filter SRIF is not frequently handled. In this research, we used the MANS-PPP software package to execute the processing method and generate the PPP GNSS solution. The new program has been demonstrated how can effectively enhance initial time and positioning error for multi-GNSS satellites. Processing observation data with the Kalman filter and SRIF was performed using PPP in static mode for the 16 stations, and the influence of errors has been analyzed from the filtering method. The Kalman filter was unable to maintain a stable convergence curve during the PPP filtering procedure, but SRIF was successful in doing so. Based on these findings, SRIF had better numerical stability and was well-suited for settings with PPP demanding precision computing environments. [ABSTRACT FROM AUTHOR]

It is critical to evaluate the reliability of using free online processing software for Global Navigation Satellite System post-processing since the advancement of GNSS gives satellite navigation customers all over the world great benefits. AUSPOS, IBGE, Magic GNSS, CSRS-PPP, and open-source software are some of the online processing solutions being evaluated for accuracy in this study. GNSS observations from IGS were used to conduct field observations using RINEX 3 data from three stations, with an observation duration of 30 seconds. After data acquisition, it was processed with online and free software that made use of GPS, GPS, and GLONASS. When compared to coordinates obtained from reference stations, the relative differences and correctness of the coordinates generated by each piece of software were then evaluated. coordinates in the ITRF14 reference for the X, Y, and Z directions. Online GNSS processing services may be used with greater accuracy for engineering and geodetic applications and are simple to use without the need for GNSS data processing expertise. [ABSTRACT FROM AUTHOR]

The modernization of GNSS provides promising improvements to satellite navigation users across the world, it is important to determine the reliability of using free online processing software for the Global Navigation Satellite System post-processing. The study aims at assessing the accuracy of two free online processing software, GAPS, and CSRS-PPP and Open-source software, PPPH MATLAB based software, and GNSS solutions. Field observations were carried out on data from three stations using GNSS observation from IGS with an observation period of 30 seconds the acquired data were post-processed using both online and opensource software. The coordinates generated from each software were then compared with the ones obtained from station to determine their relative discrepancies and accuracies. for GAPS and CSRS-PPP both in X, Y, and Z direction in ITRF14 reference. Online GNSS processing services are easy to use, do not require the knowledge of GNSS data processing and can be adopted for engineering and geodetic applications. Initial time must be checked for better resolution. [ABSTRACT FROM AUTHOR]