STABILITY TESTS FOR THE NETWORK OF PERMANENT GNSS STATIONS OF THE REPUBLIC OF SRPSKA

The network of permanent GNSS stations of the Republic of Srpska is located in a fairly seismic area and belongs to different sides of regional faults. This paper provides an overview of the stability tests for fifteen permanent stations of the SRPOS network using the published precise ephemeris of the International GNSS Service (IGS) and the downloaded RINEX data from the permanent GNSS stations of the SRPOS network. The research was conducted for the data taken during the period from April 2015 to March 2016. The paper presents position vectors for permanent stations ranging from 0.71 mm (permanent station Srbac) to 22 mm (permanent station Nevesinje).

5 anni di monitoraggio, controllo e prevenzione della pesca illegale nel Parco Sommerso di Gaiola (Golfo di Napoli)

The Gaiola Underwater Park is a small Marine Protected Area located in Naples (Italy), funded in 2002 to preserve the biological and archaeological heritage. In fact, because of the metropolitan context in which it is integrated, the area is subject to constant anthropic pressure, which often results in illegal activities, especially in the fishing sector. In this work, the results of 5 years of monitoring and control of illegal fishing inside the MPA are presented. This research had an important impulse in 2015, thanks to the collected data and to the methodology developed within the Gaiola MedPAN Project. The experience acquired in these years resulted in the funding of the StAMM Project, a permanent station for the monitoring, control and prevention of environmental offences in the MPA.

PERMANENT STATION OF SPACE GEODESY NVSK AND ISKITIM EARTHQUAKES

We discuss technical-ecological problems. Displacement and tilt results, received at permanent station Klyuchi (11 km from Novosibirsk) during Iskitim earthquakes period, were presented for 2017-2019 yy. These earthquakes happened at Iskitim coal-mines territory, 50 km from Novosibirsk and 20 km from Berdsk. We review effects connected with building of water-reservoirs and with exploitation of deposits. Space geodesy receivers GLONASS-GPS type, tilt-meters and gravimeters were used at NVSK (Klyuchi) station. This complex was used for network measurement. We discuss the results of displacement-strain observation at Ust-Balyk gas-oil deposit, Zapolyarnii gas deposit and for water-reservoir of Sayan-Shushenskoe Electric Power Station (SSEPS).

GLOBAL GEOID ADJUSTMENT ON LOCAL AREA FOR GIS APPLICATIONS USING GNSS PERMANENT STATION COORDINATES

Orthometric heights, useful for many engineering and geoscience applications, can be obtained by GPS (Global Positioning System) surveys only when an accurate geoid undulation model (that supplies the vertical separation between the geoid and WGS84 ellipsoid) is available for the considered topic area. Global geoid height models (i.e., EGM2008), deriving from satellite gravity measurements suitably integrated with other data are free available on web, but their accuracy is often not sufficient for the user’s purposes. More accurate local models can nevertheless be acquired, but often only for a fee. GPS/levelling surveys are suitable for determining a local, accurate geoid model, but may be too expensive. This paper aims to demonstrate that GNSS (Global Navigation Satellite System) Permanent Station documents (monographs), freely available on the web and supplying orthometric and ellipsoidal heights, permit to calculate precise geoidal undulations useful to perform global geoid modelling on a local area. In fact, in this study 25 GNSS Permanent Stations (GNSS PS), located in North-Western Italy are considered: the differences between GNSS PS geoidal heights and the corresponding EGM2008 1′ × 1′ ones are used as a starting dataset for Ordinary Kriging applications. The resulting model is summed to the EGM2008 1′ × 1′, obtaining a better-performed model of the interest area. The accuracy tests demonstrate that the resulting model is better than EGM2008 grids to produce contours from a GPS dataset for large-scale mapping.

Intercomparison and Validation of GNSS-IWV Derived with G-Nut and Bernese Software

GNSS is an important source of meteorological data. GNSS measurements can provide tropospheric Zenith Wet Delays (ZWD) over wide area covered with permanent stations. In addition, when using surface synoptical data, GNSS can provide Integrated Water Vapor (IWV) which is very valuable information utilized in weather forecasts and severe weather monitoring. Hence, there is a need to test and validate various algorithms and software used for ZWD estimation. In this research, the accuracy of the ZWD estimates was tested using two different software packages: Bernese GNSS Software v.5.2 and G-Nut/Tefnut. In addition, their computational load was evaluated. The GNSS data were obtained from POTS permanent station, which is located in Potsdam, Germany. To validate the estimation results, the derived ZWD was transformed into the IWV, and afterwards compared to the reference IWV measured by the collocated Microwave Radiometer. In addition, the ZWD estimates were also compared to the EUREF final solution.

Towards Reliable Velocities of Permanent GNSS Stations

In the modern geodesy the role of the permanent station is growing constantly. The proper treatment of the time series from such station lead to the determination of the reliable velocities. In this paper we focused on some pre-analysis as well as analysis issues, which have to be performed upon the time series of the North, East and Up components and showed the best, in our opinion, methods of determination of periodicities (by means of Singular Spectrum Analysis) and spatio-temporal correlations (Principal Component Analysis), that still exist in the time series despite modelling. Finally, the velocities of the selected European permanent stations with the associated errors determined following power-law assumption in the stochastic part is presented.

Analysis of GNSS Data Using Precise Point Positioning Technique for the Determination of Permanent Station in Romania

To obtain the coordinates by means of precise point positioning (PPP) technique we need to use the undifferenced GPS pseudocode and carrier phase observations but to obtain the “precise” positioning we need precise orbit and clock data too. This products and other information for obtaining the results by using PPP technique on a centimeter level accuracy can be downloaded from different locations, but the most reliable satellite ephemerides and clock correction are available from International GNSS Service (IGS). In the PPP analysis we determined the parameters such as the receiver clock error, ionospheric delays code biases, code multipath and the total neutral atmosphere delay of the observations. For the determination of the permanent station coordinates, using the PPP technique, we used precise orbit and clock solutions to enable absolute positioning of a single receiver. In this article we present the results obtained by using the PPP technique on the permanent station Oradea, from which we can conclude that the PPP technique can be used for different GNSS application.