No abstract

Recently, the interest of Unmanned Aerial Vehicle application in photogrammetric environment for roads observation and monitoring has increased in many countries, in Lithuania as well. The experimental object for demonstration of capability and efficiency of aerial vehicle-based remote sensing technology for road data collection was a western bypass of Vilnius. The platform of the model UX5 Trimble with mounted camera Sony NEX-5R was applied for gaining images. The implemented means are mobile and not expensive. Photogrammetric technique with software package Business Center Photogrammetry Module was applied for the modelling of images. The correctness of digital surface model generally depends on camera resolution, flight height and accuracy of ground control points. The coordinates of control points were determined using Global Positioning System Trimble R4. Paper demonstrates results of a new technology application possibilities for linear object (road) mapping and accuracy evaluation of spatial models. The road points positioning accuracy investigation was carried out in consideration with geodetic control measurements. The average root mean square error for the points coordinates is 2.94 cm, and standard deviations – 2.78 cm. Analyzing coincidence or mismatches of Vilnius western bypass project data with photogrammetric product, not significant discrepancies of road section features were determined. The cost consideration of Unmanned Aerial Vehicle in conjunction with photogrammetry employment at experimental object is presented.

Unmanned Aerial Vehicle (UAV) and Digital Photogrammetry is an up-to-date area mapping technology. Implemented features are low-cost, mobile and simple. UAV (fixed-wing EPP-FPV) with mounted digital camera (Canon S100) was used for imagery while digital photogrammetry processing (with lisa software application) was applied for cartographic data collection. High imagery quality is a significant factor for the efficiency and quality of standard mapping products, such as Digital Elevation Model and Ortho Images. DEM and Orthophoto quality mainly depends on camera resolution, flight height and accuracy of Ground Control Points (GCP). In experimental investigations, GCP coordinates were gained interactively from the Internet. Application of the appropriate DEM checking technique showed that DEM error was up to 0.5 m.

Santrauka. Skaitmeninės fotogrametrijos metodai taikomi ortofotografiniams žemėlapiams sudaryti. Šiam tikslui aerofotonuotraukos orientuojamos, ir formuojamas skaitmeninis Žemės paviršiaus reljefo modelis (DEM), skaitmeniniu ortofotografiniu transformavimo būdu atliekamas aerofotonuotraukų geometrinis apdorojimas -pašalinami geometriniai iškraipymai, atsiradę dėl fotokameros posvyrio, dėl centrinės projekcijos ir reljefo įtakos. Ypač svarbu skaitmeninį Žemės paviršiaus reljefo modelį sukurti tokio tikslumuo, kad būtų užtikrinta gera geometrinė skaitmeninių fotografinių vaizdų transformavimo kokybė. Skaitmeninės fotogrametrijos procesai eksperimentiškai analizuoti Aerogeodezijos institute (Kaunas) aerofotonuotraukas apdorojus skaitmenine fotogrametrine darbo stotimi PHOTOMOD. Šia programine sistema generuotas reljefo modelis (DEM) bei ortofotografinė nuotrauka, atlikus aerofotografinių vaizdų vidinį, reliatyvųjį bei absoliutųjį orientavimą. Skaitmeninis reljefo modeliavimas atliktas sukuriant netaisyklingų trikampių tinklinius modelius -TIN (Triangulated Irregular Network), sudarytus iš nesutampančių trikampių. Taikyti šie paviršiaus interpoliavimo metodai: adaptyvusis (adaptive), glodusis (Inverse Distance Weighted (IDW)) ir reguliarusis (Radial Basis Functions (RBF)). Atlikta palyginamoji skaitmeninių reljefo modelių, taikant skirtingus reljefo interpoliavimo metodus, analizė. Rekomenduojama taikyti adaptyvųjį reljefo interpoliavimo metodą. Skaitmeninė programinė įranga LISA (Berlynas, Vokietija) taikyta skaitmeninio vietovės reljefo modelio kokybei tirti ir tikslumui vertinti.