Geomatics and Environmental Engineering
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ISSN 1898-1135
e-ISSN: 2300-7095
Issue Date
2021
Volume
Vol. 15
Number
No 4
Description
Journal Volume
Geomatics and Environmental Engineering
Vol. 15 (2021)
Projects
Pages
Articles
Accuracy assessment of a variety of GPS data processing, online services and software
(Wydawnictwa AGH, 2021) Mohammed, Israa H.; Ataiwe, Tariq N.; Al Sharaa, Hisham
The processing of GPS observations in precise positioning is complex and requires professional surveyors since it must be carried out after each static measurement. In GPS network adjustment, the obtaining of the correct coordinates of the determined point is possible after determining the components of GPS vectors and aligning the networks of these vectors, while PPP requires the availability of precise products for the reference satellites orbits and clock. For that reason, surveyors can take advantage of free online GPS data processing. In this paper, the authors compare the results obtained from different sources of free online GPS data processing (AUSPOS, OPUS, CenterPoint RTX, APPS, MagicGNSS, CSRS-PPP, GAPS, and SCOUT) in terms of their accuracy, availability, and operation. This is then compared with free GPS processing soft - ware (gLAB and RTKLIB), and finally with commercial software (TBC Trimble Business Center). The results show that online processing services are more accurate than offline processing software, which indicates the strength of their algorithms and processes. The CSRS-PPP online service had the best results. The difference between the relative solution of AUSPOS and OPUS, and CSRS-PPP is insignificant.
Green space assessment and management in Biscay Province, Spain using remote sensing technology
(Wydawnictwa AGH, 2021) Makinde, Esther O.; Andonegui, Cristina M.; Vicario, Ainhoa A.
Our ecosystem, particularly forest lands, contains huge amounts of carbon storage in the world today. This study estimated the above ground biomass and carbon stock in the green space of Bilbao Spain using remote sensing technology. Landsat ETM+ and OLI satellite images for year 1999, 2009 and 2019 were used to assess its land use land cover (LULC), change detection, spectral indices and model biomass based on linear regression. The result of the LULC showed that there was an increase in forest vegetation by 12.5% from 1999 to 2009 and a further increase by 2.3% in 2019. However, plantation cover had decreased by 3.5% from 1999-2009, while wetlands had also decreased by 9% within the same period. There was, however, an increase in plantation cover from 2009 to 2019 by 2.1% but a further decrease in wetlands of 4.3%. Further results revealed a positive correlation across the three decades between the widely used Normalized Differential Vegetation Index (NDVI) with other spectral indices such as Enhance Vegetation Index (EVI) and Normalized Differential Moisture Index (NDMI) for biomass were: for 1999 EVI (R 2 = 0.1826), NDMI (R2 = 0.0117), for 2009 EVI (R 2 = 0.2192), NDMI (R2 = 0.3322), for 2019 EVI (R2 = 0.1258), NDMI (R 2 = 0.8148). A reduction in the total carbon stock from 14,221.94 megatons in 1999 to 10,342.44 megatons 2019 was observed. This study concluded that there has beena reduction in the amount of carbon which the Biscay Forest can sequester.
Studying the sensitivity of satellite altimetry, tide gauge and GNSS observations to changes in vertical displacements
(Wydawnictwa AGH, 2021) Pająk, Katarzyna; Kowalczyk, Kamil; Kaminskis, Jānis; Idzikowska, Magdalena
Tide gauge observations provide sea level relative to the Earth's crust, while satellite altimetry measures sea level variations relative to the centre of the Earth's mass. Local vertical land motion can be a significant contribution to the measured sea level change. Satellite altimetry was traditionally used to study the open ocean, but this technology is now being used over inland seas too. The difference of both observations can be used to estimate vertical crustal movement velocities along the sea coast. In this paper, vertical crustal movement velocities were investigated at tide gauge sites along the Adriatic Sea coast by analyzing differences between Tide Gauge (TG) and Satellite Altimetry (SA) observations. Furthermore, the estimated vertical motion rates were compared with those from nearby GNSS measurements. The study determines the practical relationships between these vertical crustal movements and those determined from unrelated data acquired from the neighbouring GNSS stations. The results show general consistence with the present geodynamics in the Adriatic Sea coastal zone.
Housing price forecasting in selected Polish cities during the COVID-19 pandemic
(Wydawnictwa AGH, 2021) Bełej, Mirosław
The COVID-19 pandemic represents a combined supply and demand shock to the financial and housing market but also an unusual negative shock in terms of the health of society (households) and national economy. The fall in housing demand was initially assumed together with price decreases as a consequence of the uncertainty of the health of society, significant falls in stock markets and corporate solvency. However, the results of research in selected Polish cities do not indicate such a significant market recession. This article examines the housing price dynamics and forecasting in Polish cities during the COVID-19 pandemic. The TRAMO/SEATS and ARIMA models were used for the decomposition and forecasting of dwelling time series. The Polish housing market, represented by selected local housing markets, still shows a growing trend despite the COVID-19 pandemic throughout 2020. The housing market may slow down in 2021, but the strong forecasted growth trends in Warszawa and Poznań suggest that there will be no significant price decline in Poland in the near future.
Verification of the geometrical representation of buildings in cadastre using UAV photogrammetry
(Wydawnictwa AGH, 2021) Karabin, Marcin; Bakuła, Krzysztof; Łuczyński, Robert
The aim of this study was to determine the potential benefits of using UAV-based data to verify the accuracy of the geometry of the outlines of buildings registered in a cadastral database, and to investigate the potential use of data from UAV platforms in measuring the buildings. The authors examined whether the acquisition of data from UAVs can replace field measurements or only support them. The advantages and disadvantages of such data acquisition methods, compared with more well-established measurement methods, were identified.