The article concerns the issue of using imagery reconnaissance sensors for the identification of geological-engineering conditions in river channels, in the aspect of evaluating the forcing of a water obstacle. It discusses the issues associated with using air platforms (manned and unmanned) in remote sensing surveying of selected fragments of the Vistula and Bug river channels and the correct interpretation of the obtained results, through their verification using bathymetric tests conducted directly in the river channels.

Abstract:The usefulness of low-altitude aerial photography for the assessment of channel morphodynamics of a lowland river. The paper presents examples of using low-altitude aerial images of a modern river channel, acquired from an ultralight aircraft. The images have been taken for two sections of the Vistula river: in the Małopolska Gorge and near Dęblin and Gołąb. Alongside with research fl ights, there were also terrestrial investigations, such as echo sounding of the riverbed and geological mapping, carried out in the river channel zone. A comparison of the results of aerial and terrestrial research revealed high clarity of the images, allowing for precise identifi cation of the evidence that indicates the specifi c course of river channel processes. Aerial images taken from ultralight aircrafts can signifi cantly increase the accuracy of geological surveys of river channel zones in the Polish Lowlands due to low logistic requirements.

This article presents the preparation and performance of tests of a GPS receiver in terms of confirming the selected technical parameters. Due to impossibility to carry out the tests with the use of classic ground methods, an unconventional method that uses a Sonex LL air platform was developed.