Skaitmenines fotogrametrijos metodai taikomi ortofotografniams žemelapiams sudaryti. Šiam tikslui aerofotonuotraukos orientuojamos, ir formuojamas skaitmeninis Žemes paviršiaus reljefo modelis (DEM), ...skaitmeniniu ortofotografniu transformavimo būdu atliekamas aerofotonuotrauku geometrinis apdorojimas - pašalinami geometriniai iškraipymai, atsirade del fotokameros posvyrio, del centrines projekcijos ir reljefo itakos. Ypač svarbu skaitmenini Žemes paviršiaus reljefo modeli sukurti tokio tikslumuo, kad būtu užtikrinta gera geometrine skaitmeniniu fotografniu vaizdu transformavimo kokybe. Skaitmenines fotogrametrijos procesai eksperimentiškai analizuoti Aerogeodezijos institute (Kaunas) aerofotonuotraukas apdorojus skaitmenine fotogrametrine darbo stotimi PHOTOMOD. Šia programine sistema generuotas reljefo modelis (DEM) bei ortofotografne nuotrauka, atlikus aerofotografniu vaizdu vidini, reliatyvuji bei absoliutuji orientavima. Skaitmeninis reljefo modeliavimas atliktas sukuriant netaisyklingu trikampiu tinklinius modelius - TIN (Triangulated Irregular Network), sudarytus iš nesutampančiu trikampiu. Taikyti šie paviršiaus interpoliavimo metodai: adaptyvusis (adaptive), glodusis (Inverse Distance Weighted (IDW)) ir reguliarusis (Radial Basis Functions (RBF)). Atlikta palyginamoji skaitmeniniu reljefo modeliu, taikant skirtingus reljefo interpoliavimo metodus, analize. Rekomenduojama taikyti adaptyvuji reljefo interpoliavimo metoda. Skaitmenine programine iranga LISA (Berlynas, Vokietija) taikyta skaitmeninio vietoves reljefo modelio kokybei tirti ir tikslumui vertinti.
The rectification of high resolution digital aerial images or satellite imagery employed for large scale city mapping is modern technology that needs well distributed and accurately defined control ...points. Digital satellite imagery, obtained using widely known software Google Earth, can be applied for accurate city map construction. The method of five control points is suggested for imagery rectification introducing the algorithm offered by Prof. Ruan Wei (tong ji University, Shanghai). Image rectification software created on the basis of the above suggested algorithm can correct image deformation with required accuracy, is reliable and keeps advantages in flexibility. Experimental research on testing the applied technology has been executed using GeoEye imagery with Google Earth builder over the city of Vilnius. Orthophoto maps at the scales of 1:1000 and 1:500 are generated referring to the methodology of five control points. Reference data and rectification results are checked comparing with those received from processing digital aerial images using a digital photogrammetry approach. The image rectification process applying the investigated method takes a short period of time (about 4-5 minutes) and uses only five control points. The accuracy of the created models satisfies requirements for large scale mapping.
Digitalno modeliranje Zemljine površine metodama satelitske stereofotogrametrije i daljinskih istraživanja provodi se u svrhu izrade matematički aproksimirane površine koja joj najbolje priliježe. ...Pri izradi modela određuju se položaj i visina pojedine točke detalja na površini u odnosu na neku referentnu točku i interpolacijom između tih točaka vizualizira se neprekidna aproksimirana površina terena. Takvi modeli u današnje vrijeme imaju vrlo široku primjenu u različitim znanstvenim disciplinama i neusklađenu terminologiju. U članku je prikazan pregled inozemne i hrvatske terminologije u kojoj je primjetan nedostatak preciznije definiranih pojmova kojima bi se jasnije raščlanila semantička podjela rezultata u procesu digitalnog modeliranja površine Zemlje. S tim u vezi, u članku su predstavljena dva nova termina: digitalni model tla i digitalni model scene u svrhu preciznije definicije pojmova digitalnih modela Zemljine površine. Prikazan je i kratak osvrt na današnje mogućnosti izrade digitalnih modela Zemljine površine u satelitskoj stereofotogrametriji i daljinskim istraživanjima u odnosu na prostornu rezoluciju stereostelitskih snimaka i metode osiguravanja stereopreklopa između njih.
Hiperspektralna blizupredmetna snimanja objekata obuhvaćaju prikupljanje i obradu spektralnih karakteristika reflektiranog elektromagnetskog zračenja (EM) objekata koji se nalaze na takvim ...udaljenostima od senzora da se ne može smatrati da se nalaze u optičkoj beskonačnosti. Hiperspektralni skeneri koji se koriste u blizupredmetnim snimanjima prvenstveno su dobro kalibrirani u spektralnoj domeni dok je njihova prostorna kalibracija upitna ili uopće nije provedena. Točkasti skeneri su najčešće korišteni hiperspektralni skeneri sa vrlo širokom upotrebom. Za razliku od točkastih skenera, kalibrirani linijski skener osim kvalitetne spektralne daje i točnu prostornu informaciju. Za geokodiranje spektralnih podataka prikupljenih senzorom potrebno je izraditi i implementirati matematički model preslikavanja scene na ravninu snimke, uzimajući u obzir očekivane sistematske pogreške koje utječu na rezultate mjerenja. Stoga je u ovom radu izveden i prezentiran novi algoritam za kalibraciju linijskih skenera. Testiranje je obavljeno pomoću hiperspektralnog linijskog skenera ImSpector V9 + PixelFly.
The Stična monastery is a monument of national importance. The monastery cloister needed some restoration work. Projects were prepared and restoration works were carried out between 1996 and 2004. ...The inappropriate and non-original plaster of the inner and outer walls of the cloister was removed in 2003. At that moment it was possible to make a photogrammetric survey and a protective recording of the stripped walls. The goal was to preserve all possible data about the walls before the new lime plaster was made. An unprofessional camera was used for the task. Each wall of the cloister was covered by forty-two shots (the cloister has eight walls, four inner and four outer walls surrounding the garden). The data have been preserved on film and transformed into digital form. Both forms are available for study, analysis and further processing. The acquired data represent a valuable contribution to the existing documentation and knowledge about this monument. The photographs were taken according to the recommendations for simple photogrammetric architectural survey denominated as 3 x 3 rules for architectural photogrammetry. In 1988, Martin Brunner defined in his diploma thesis the 3 x 3 Minimum Rules for Photogrammetry (secondary source: Herbig, Waldhäusl, 1997). They were updated and developed into the present form by Peter Waldhäusl, Cliff Ogleby and Ulrike Herbig. The use of these rules is recommended and supported by the International Committee for Architectural Photogrammetry (CIPA) (http://cipa.icomos.org), which is one of the international committees of ICOMOS (International Council on Monuments and Sites) and it was established in collaboration with ISPRS (International Society of Photogrammetry and Remote Sensing). Its main purpose is the improvement of all methods for surveying of cultural monuments and sites under special consideration of pphotogrammetry. These so-called ˝3 x 3 rules˝ are structured into three geometrical rules, three photographic rules and three organizational rules. The aim of implementing the rules is to create a possibility for anyone to use their own camera for amateur photogrammetric stereo block documentation, which can even be used for restitution if needed later on. In this way there is a possibility to create or supplement documentation material on cultural heritage and in a way to preserve it for the future.
Determination of the geometry of aircraft surfaces has always been an extremely complicated task, though it is very important for the aerodynamic properties of the entire aircraft or its parts (like ...wings, body, rudders, etc.). Measurement of the geometrical properties of aircraft parts is especially difficult due to the smoothness of their surfaces. Here in this paper a short review of two methods of determining the shape of aircraft parts are given: one relies on determining point position by means of laser-based scanning and another relies on photogrammetry. A comparison of the results of both methods applied to the same aircraft element is also presented.
In the article, the application of stereopairs of panchromatic and multispectral SPOT satellite imagery in photogrammetric applications is presented. Theoretical basis of the generation of digital ...elevation models and orthoimages and a description of the practical processing of orthoimages are given. Examined are the possibilities of the application of the middle-resolution images from mountainousregions. The accuracy of the orthoimages has been determined by comparing with orthophotos DOF 5. The results are unexpectedly good and show the potential of SPOT imagery. The accuracy of the resultshas been, in addition to the input data, affected by the restrictions of the digital, automatic processing techniques in the software applied.
The paper describes the procedure of generating a 3D metric building model using a low-cost program package that operates on principles of multiple-image ray intersection. The advantage of the method ...is that stereoview is not required and we do not need a photogrammetric instrument or workstation for 3D data acquisition. The method was tested on two buildings. The program package Photomodeler version 5 was used, enabling the complete project accomplishment that includes camera calibration, image measurements, adjustments of object coordinates, generation of surface 3D models and photorendering. The phases of the project are described as well as limitations and problems encountered in practice. The results show good potentials for broad use in different applications.
Potrajno gospodarenje šumama zahtijeva prostorno i vremenski određene informacije o stanju šume koje se još uvijek u mnogim zemljama svijeta, uključujući i Hrvatsku, prikupljaju na tradicionalan ...način, terenskom izmjerom. Iako terenska izmjera pruža informacije zadovoljavajuće točnosti, ona zahtijeva dugotrajan i intenzivan rad. Stoga se u novije vrijeme intenzivno istražuju mogućnosti upotrebe laserskih skenera i fotogrametrijskih metoda kao brza i efektivna alternativa klasičnom pristupu izmjere šuma. U ovom je radu prikazan algoritam za ekstrakciju opsega i modeliranje debla iz fotogrametrijskog oblaka točaka baziran na RANSAC (engl. Random Sample Consensus) algoritmu i metodi rastavljanja na glavne komponente (engl. PCA – Principal Component Analysis). Analizirana je točnost ekstrakcije opsegā na jednom deblu u ovisnosti o tipu kalibracije kamere (predkalibrirana, samokalibracija s inicijalnim parametrima, samokalibracija). Najmanja pogreška dobivena je predkalibriranom kamerom (RMSE=1,23 cm), slijede samokalibracija s inicijalnim parametrima (RMSE=1,35 cm) i samokalibracija (RMSE=1,63 cm). Predstavljeni algoritam pokazuje veliki potencijal primjene fotogrametrijskih mjerenja pri određivanju opsega debla, uz određene preinake u pristupu.
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