PERSPECTIVE VIEWS AND PANORAMAS IN PRESENTATION OF RELIEF FORMS IN POLAND

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1 PERSPECTIVE VIEWS AND PANORAMAS IN PRESENTATION OF RELIEF FORMS IN POLAND Waldemar Rudnicki Institute of Geodesy and Cartography, ul. Modzelewskiego 27, Warsaw, Poland Tel: , Fax: Presentation of relief forms in a visual way implies application of other kinds of presentations than conventional contour map. It was proposed to apply in the electronic atlas, which is prepared at the Institute of Geodesy and Cartography, perspective views and panoramas, as well as shading of relief forms, in order to supplement basic map material with additional information. Preparation of DEM and orthophotomap with the use of digital photogrammetry is planned within the project. For larger terrain forms satellite images will be used, while for smaller forms aerial and ground photographs will be applied. Perspective views will be created on the basis of DEM and aerial or satellite orthophotomaps, using Intergraph and Alias software. It is also planned to prepared panoramas in the field with the use of panoramic heads. The selected relief forms are: eskers, drumlins, kames, dunes, terminal moraines, river valleys with terraces and examples of Karst relief. Presentations of these forms will be done within Director and Flash (Macromedia) environment. The relief forms presented on topographic contours maps are difficult to detect and imagine. Therefore, the project of preparing digital atlas of relief forms was started at the end of last year. The work concentrates on process of perception and detection geomorphological form of terrain on territory of Poland. The relief form should be shown in proper way without misunderstanding by using several methods of cartographic visualization. Shading processes, block diagrams and panoramic view are in the common use to achieve good results on form presentations [4] in contrary to contours maps which give us instead a lot of information about terrain. In the project of atlas we plan to create panoramas on a basis of photographs acquired with use of panoramic head and virtual panoramic views with the use of aerial photographs, satellite imagery and DEM. Eight different kinds of form were chosen at the first stage of the project and their approximate locations were shown on fig. 1. Figure 1. Sketch of location of the examined terrain forms

2 Name of form and location on topographic map in 1942 coordinate system: 1). Dunes N-33-47D; 2). River valleys with terraces N A, N C; 3). Kames N B, N D, N A, N C; 4). Tunnel-valley lakes N D; 5). Karst island mountains M A; 6). Drumlins N-34-74; 7). Terminal moraine N C; 8). Karst relief M D, M C. Terrain forms with small range and denivelation can be shown by panorama or series of photos taken in object mode. For panorama preparation we use panoramic head. The shown one is a Manfrotto 302 Plus. Panoramic head has changing angle of rotation:10, 15, 18,20, 24, 30, 36,45, 60, 90 degrees, level adjustment with precision degrees and two sliding plates for precise positioning optical center of lens on the panoramic axis of rotation in order to avoid parallax errors. Figure 2 A) B) Figure 3 A) B) Location of line, which forms symetrical distribution of distortions in case of vertical photo acquistion, is defined by horizontal plane intersecting optical centre of the lens. In non-typical applications, e.g. when vertical photo acquisition cannot be done, tilted photographs are taken (fig. 3A). However, it must be mentioned, that these photographs do not keep appropriate proportions of the presented object. Character of distortions was shown in fig. 3B, in case, when lens was tilted up, red line in then determined by horizontal plane intersecting optical centre of the lens. Software for panorama stiching solve both cases shown above, by changing lens parameters and view angle above and below horizontal plane. Photographs were corrected geometrically and merged in an automatic way. Sometimes the automatic stiching mode does not work properly: then we had to mosaic photo manually. Example of settings in Quick Time VR Authoring Studio software [1]- panoramic view from 100 meters above terrain level, tilted camera, view angle 10 degrees above and 60 degrees below line of horizont is presented in fig. 4.

3 Fig. 4 Example of QTVR Autoring Studio playback settings. While making panoramas with the use of computer programs, rules of creating DTM and virtual cameras must be known. For large terrain forms this method in the only solution, because it does not have limitations, which exist while creating terrain panoramas. Selection of suitable parameters of the lens, according to needs, does not involve in this case purchase of modern, expensive photographic equipment. Observation angle of camera is selected depending on size of terrain form and its extent. For small, isolated forms we can use view, in which we locate object just in the centre. For project purposes various terrain forms, from several to tens of meters in size, were chosen. Figure 5 A) B) Figure 6 A) B) For creating DTM and restitution of correct shape of terrain forms Intergraph system of digital photogrammetry was applied, using autocorrelation method, with defining its parametres for particular terrain forms. Programs for modelling illumination and texture were: Terrain Analyst (Intergraph) and Maya (Alias). Similarly to panoramas created in conventional way we reconstructed conditions of photographing with tilting camera axis and without it (fig. 5A, fig. 6A). As it can be seen, lines of distortion are not affected with lens distortion (fig. 5B, fig. 6B). This feature helps in more efficient work on visualisation of relief forms.

4 Figure 7 Process chain from a photo to a multimedia file Digital representation of these forms as DTM must be transferred from photogrammetric programs to Maya (Alias). In this program proper illumination of scene is assigned, in order to cause appropriate spatila effect. In case of aerial and satellite photographs acquired on northern hemisphere procedure of shadow reconstruction and their removal will be applied [3], and next shading procedure, which gives positive spatial effect, will be used. Photographs prepared in such a way will be entered into panorama procedure (fig. 7), with selection of full, partial or object option. In case, when, panorama will not be able to be created, perspective views are planned to be done. Data prepared in this way must be transformed to polygons [2], and after process of shading and texturizing exported to Shockwave files and finally placed in Director file (Macromedia). The project was started at the end of 2004; it is now in the phase of field works aimed at selection of representative relief forms. REFERENCES [1] Apple Computer, Inc. 1997, QTVR Authoring Studio User s Manual; [2] Alias, 2000, Using Maya polygonal modeling.; [3] Rudnicki W, The new approach to the relief shading applied in satellite image maps High Mountain Cartography 2000Dresden University of Technology, p [4] Zarzad Topograficzny Sztabu Generalnego, 1960, Atlas form i typow rzezby terenu Polski, WZKart.

5 PERSPECTIVE VIEWS AND PANORAMAS IN PRESENTATION OF RELIEF FORMS IN POLAND Biography Waldemar Rudnicki Institute of Geodesy and Cartography, ul. Modzelewskiego 27, Warsaw, Poland Tel: , Fax: Present position: Ph. D. Waldemar Rudnicki - Assistant Professor at Cartography Department of the Institute of Geodesy and Cartography. Date of birth: 26 March, 1969 Nationality: Polish Civil status: Married, 2 sons Education: Institution University of Technology Warsaw, Dates: 1997 Degree(s) or Diploma(s) obtained M.Sc. diploma in Photogrammetry and Cartography Institution Institute of Geodesy and Cartography, Warsaw Dates: 2002 Degree(s) or Diploma(s) obtained Ph.D. Professional experience: Since till now specialist, lecturer, senior lecturer, tutor at Institute of Geodesy and Cartography. Activities: His major activities concentrate on research concerning: visualization, multimedia creation, VR, panorama. Publications, mainly in Polish scientific journals. Author and co-author of several satellite image maps: three of them were awarded for innovative technology and design and one for excellence in cartography by ICA (2001) in satellite image map category. Member commission on Mountain Cartography of ICA. Hobby: Since 1985 photography.