Fig.15 Viewing the image resource
view as INI-file view as text copy copies resource to clipboard paste pastes resource from clipboard (for example to another project) rename renames resource delete deletes resource export exports resource to file import imports resource from file show hidden resources shows/hides hidden resources in PHOTOMOD Explorer window, for example files of PHOTOMOD resources backup and to restore them if needed show additional details turns on an additional columns with information, that also could be sorted by mouse click on the column header: ID resource identifier in PHOTOMOD system Host local computer, the host of the current resource Storage name of the storage where the resource located properties (duplicated by the icon ) opens a window with the resource properties (ID, type, subtype) for viewing and editing (such as the description), see Fig.13.

12. Geodetic calculator

An additional PHOTOMOD system utility, used for recalculating of ground control points coordinates from one coordinate system into another. Prior to work with GeoCalculator you should install coordinate systems database during PHOTOMOD system installation (see PHOTOMOD Montage Desktop User Manual). Geodetic Calculator is starting from OS Windows Start menu: Start | Programs | PHOTOMOD | Geodetic calculator. At first program launch you should specify the path to folder containing coordinate systems database in the window appeared.
Fig.16 Selection of folder with coordinate system database
Then the dialogue of the program settings is opened, (also could be opened using menu Options). Upper panel of the window command Tools | Options, or the icon Database directory shows the path to the database folder and allows to change it if needed. If coordinates calculations have poor result the field with invalid value is shown in red color (by default) or by color selected in drop-down list in Colors panel.
Fig.17 Program settings Interface mode panel allows to select one of two working modes: Standard and Advanced which have different set of menu commands (appeared after pushing Database menu option) for work with coordinate systems database. Standard set of Database menu contains the following items:
Advanced set of Database menu contains the following items:
After pushing the button OK in Options window the main PHOTOMOD GeoCalculator window is opened.
Fig.18 Program window (Fig.18) consists of two panels left and right. One of them is intended for initial GCP data input and the other for displaying of recalculating results. For example, you have initial GCP coordinates set in geodetic coordinate system (Lat, Long, H). In order to re-calculate them into Cartesian, which are acceptable in PHOTOMOD system you should do the following. Push the Select button in Reference system field of the left panel and select coordinate system of input GCPs. Then load ASCII file with points coordinates (the Load button in left Points field). In the right panel in Reference system field exactly in the same way select the output coordinate system (from Cartesian ones available, for example) and recalculate the coordinates (the Calculate button under left Points field or the icon Calculate from left to right). After that, new GCP coordinates appear in the right Points field. You can save them in txt file (the Save button under right Points field) and use then in further work with PHOTOMOD project.

The dialog allows setting the following parameters: Path to DGN files folder to be searched for the DGN files to process (including all subfolders). Text to find text string to be searched for and replaced. Replace with text string to replace the Text to find. Case sensitive option controlling whether Text to find is matched against in case sensitive or insensitive way. When OK button is clicked, the given path is searched for DGN files, which in turn are searched for the text to find, which is replaced with replacement string. Files having unsupported format are not modified. Note: no backup copies of the processed files are created.

15.1.2 Merge DGN files

This command is used to merge several DGN v7 files into single one. This may be necessary e.g. for creating summary files for several regions. When this button in the main window of the program is clicked, first an Open dialog is displayed for selecting input files to merge, then a Save as dialog is displayed to enter the name for the resulting merged file.
15.1.3 Fill sheets by polygons
Sometimes during orthophoto creation there arises a requirement for the raster to be exactly limited by a set of polygons (describing e.g. settlement borders), all the rest being filled by the background solid color. In order to achieve this, the Fill sheets by polygons command may be used. When the corresponding button in the main window of the program is clicked, it brings up the same-name dialog.
This dialog allows setting the following parameters: Images files image files to be processed. Acceptable formats include striped TIFF and BMP without compression, georeferenced. File with polygons vector files containing polygons to be used as borders. Acceptable are PHOTOMOD resources (.PHR), DXF, Shapefile (.SHP) formats. Color color to be used as the background fill. Create backup this option causes the program to create a backup copy (with.bak extension) before processing each raster file. Swap X, Y this option causes the X and Y coordinates of border polygons to be swapped before processing. Polygons must be specified in the same coordinate system as the raster georeference data.
15.1.4 Replace font size in MIF/MID files
This command allows to adjust font size (by changing one specified value to another one) in a set of MIF/MID files. When the corresponding button in the main window of the program is clicked, an Open dialog is brought up to select the list of files to be processed, followed by the parameters dialog.

Fig.27 NuVision 60GX-NSR glasses kit Beside the shutter glasses you can use simple anaglyph glasses with red and blue filters. Anaglyph stereomode requires no special equipment but it is not completely good for working with color images. Another disadvantage is that the picture gets a bit darker when viewing with filters.

Fig.28 Anaglyph glasses

16.2 Video cards

For IBIK glasses work

Video cards Matrox G200, G400, G450, G550 ATI Radeon Mach64, Rage, RageII, Rage128 Intel i740, i810, i815 Nvidia GeForce 2,3,4 Nvidia Quadro Mode Interlace Pageflipping yes no Interlace mode configuration standard work using the IBIK driver
standard work using the IBIK driver

3D labs Wildcat

Interlace mode is turned On by using the video card driver. Using IBIK driver in Default stereo mode turns On the glasses.
For NuVision 60GX-NSR glasses work
Video cards Matrox G200, G400, G450, G550 ATI Radeon Mach64 Rage, RageII, Rage128 Intel i740, i810, i815 Nvidia GeForce 2,3,4 Nvidia Quadro 3D labs Wildcat Mode Interlace Pageflipping yes/no no Interlace mode configuration Interlace mode is turned On using video driver on those video cards where it is possible. The button on the synchronization box turns On the glasses.

no yes

yes yes
Interlace mode is turned On by the video card driver. The button on the synchronization box turns On the glasses.
For NuVision 60GX glasses work
Video cards Nvidia QuadroXGL QuadroXGL QuadroXGL QuadroXGL QuadroXGL QuadroXGL QuadroXGL Quadro FX 330 Quadro FX 500 Quadro FX 1000 Quadro FX 2000 3D labs Wildcat VP760 Wildcat VP870 Wildcat VP970 Wildcat 4105 Wildcat 4110 Wildcat 4210 Wildcat II 5000 Wildcat II 5110 Wildcat III 6110 Wildcat III 6210 Wildcat Wildcat Interlace no Mode Page-flipping yes Interlace mode configuration
Interlace mode is turned On by the video card driver. Glasses are On automatically
PHOTOMOD system also supports ATI video cards (fireGL series) for work in page-flipping. Note. For working in page-flipping mode you need a video card supporting quadbuffering mode and its driver must support Open GL 1.2 and higher standard. For working in interlace mode the video card just should support interlace mode
In case of using IBIK glasses you should install driver and set up the glasses in Default mode (see the chapter 15.1 Stereoglasses). If using NuVision 60GX glasses the IR-emitter is connected to the video card and the glasses are On automatically when switching to the stereomode. The NuVision 60GX-NSR glasses are turned On by pressing the button on the synchronization box. Note. When purchasing video card, make sure that its interface (AGP or PCI Express) is compatible with interface of the motherboard installed on your computer Below there is a list of some recommended video cards for work in page-flipping stereo mode. Nvidia Quadro2 Nvidia QuadroXGL Nvidia QuadroXGL Nvidia QuadroXGL Nvidia QuadroXGL Nvidia QuadroXGL Nvidia QuadroXGL Nvidia QuadroXGL Nvidia Quadro FX 330 (PCI Express interface) Nvidia Quadro FX 500 Nvidia Quadro FX 540 (PCI Express interface) Nvidia Quadro FX 1000 Nvidia Quadro FX 1300 (PCI Express interface) Nvidia Quadro FX 1500 (PCI Express interface) Nvidia Quadro FX 2000 3D labs Wildcat VP760 3D labs Wildcat VP870 3D labs Wildcat VP970 3D labs Wildcat 4105 3D labs Wildcat 4110 3D labs Wildcat 4210 3D labs Wildcat II 5000 3D labs Wildcat II 5110 3D labs Wildcat III 6110 3D labs Wildcat III 6210 3D labs Wildcat 3D labs Wildcat Note. Graphic cards Nvidia of GeForce series do not support page-flipping stereo mode Actually the list of video cards in the table is not complete. However the out-of-list video card may need some adjustment and testing.

16.4.5.2 Hand wheels and foot pedals Vector-A
Hand wheels and foot pedals Vector-A (produced by EOMZ, Moscow) are used for 3D photogrammetric images processing in PHOTOMOD system. Equipment delivery set includes right and left hand wheels (to perform marker move in plane), foot wheel (to move marker in height) and three pedals (which are assigned to mouse
buttons actions, selected by user). These devices are connected to the PC via special card inserted into COM-port (see hardware installation details in equipment User Manual). After devices installation to your PC, turn PC on and run PHOTOMOD System Monitor module. Then open the window with mouse settings (menu command Service | Mouse setup in PHOTOMOD Montage Desktop module), push the Device setup button and select Hand wheels/foot pedals Vector-A in Used mice field, see the chapter 15.4 Mice and hand wheels adjustment for stereo processing. Then in Device parameters panel select COM-port used for this equipment. You can adjust hand wheels sensitivity in XY axes using XY plane sensitivity slider, and also foot wheel movement sensitivity, which operates marker in Z axis (using Z sensitivity slider). If you need to re-assign X and Y axes to left and right hand wheels, check the option Swap X and Y. And if you need to invert movement of marker by right, left or foot wheels, check an appropriate option Invert X, Y or Z motion.
Fig.50 Vector-A devices adjustment in Mouse configuration window After that push Apply and OK buttons and the following picture appears in Mouse setup window.
Fig.51 Setup of foot pedals Vector-A This window contains list of macros existing in default driver or created/edited by the user in Macro editor, see the chapter 15.4.6 Macro editor. The rightmost window contains of two tabs, one of which allows to setup standard mouse buttons (see the chapter 15.4.1 Three and five button mice), and on the second one (Hand wheels/foot pedals Vector-A) markers actions after pressing each of three pedals. To assign new macro or existing to chosen pedal, select the action in Macros list, then select pedal in the Available buttons list, and assign the action to the pedal by pushing the icon Add binding (or by double mouse click). If you need to cancel the assignment, Delete binding.

16.4.6 Macro editor

PHOTOMOD system includes the set of macro commands for mouse, which could be edited up to user needs and then assign the commands for chosen mouse buttons or foot pedals, if such special photogrammetric equipment is used for images stereo processing. To open the window with macro list, push the button in the Mouse setup window (see the chapter 15.4 Mice and hand wheels adjustment for stereo processing, Fig.3), after that Macro editor window appears. In the left part of the window there is a list of macro commands that are included into mouse driver by default.

button, input new macro name, then select this macro in To create new macro push the the left list of Macro editor window. To the right of the list there are two windows used for assigning chosen actions to buttons. Upper window (Actions on button down) includes operations list, executed when button is pushed down.
To select an action and save it into macro push the button window to open the following panel:

(add action) under this

Fig.53 Creating new action for macro Here you can select one of two ways: Press selected mouse button after that you should indicate the exact mouse button (left, right or middle) in pop-down list to be pressed Press selected key press chosen key on the shown keyboard (it will be highlighted in green) After selecting the set of actions you can save the set (Cancel button) or save it (OK button), then this action appears in Actions on button down window. The rest buttons under actions list are used for the following: - delete action - move down - move up - autocreate sequence for button up automatically adds and completes the action which was started by mouse pushing. For example, if you need to assign Ctrl-Z keys pressing to mouse button click, you can assign pushing Ctrl and Z keys, and then push icon to add releasing of Ctrl and Z keys and automatically complete the macro, that will be visualized in this window. In the same way you can include to macro command in Actions on button up window the actions which are executed after releasing of chosen mouse button. When all necessary actions are included into selected macro, save them by pushing OK.
16.5 Hardware settings for working in stereomode
For convenient working in page-flipping and interlace stereomodes you should setup your video card properly. Main condition for page-flipping mode correct work is video card with quad buffering support and card driver set for Open GL (version 1.2 and higher) support as mentioned in the chapter 15.2 Video cards. Lets illustrate such settings by the example of
Nvidia QuadroXGL card. For that you should open QuadroXGL tab by the command Start | Settings | Control Panel | Display | Settings | Advanced and make the following:

Fig.54 Nvidia QuadroXGL video card settings for page-flipping stereo If you are working in interlace stereo with video card of Nvidia type you should pay attention to hardware acceleration settings of your monitor (Fig.55). Note. Nvidia video cards are working in interlace stereo mode only with IBIK stereo glasses and their driver installed (see the chapter 15.1 Stereoglasses) Open settings panel using the command Start | Settings | Control panel | Display | Settings | Advanced, Troubleshooting tab, and place Hardware acceleration slider on the next to last point for best stereo working:
Fig.55 Interlace settings
17. Distributed processing

17.1 General information

PHOTOMOD system includes the function of distributed creation of orthomosaic with parallel processing of one project in several threads on a single computer as well as on several computers in the LAN. Distributed creation is supported only for mosaic split into sheets; a unit of the distributed processing (a task) is creation of one or more sheets of the output orthomosaic. Thus the capabilities of the modern multi-core CPUs are fully utilized, as well as the computational resources of the local network. The processing may be controlled from any of the workstations involved in the process, i.e. one operator can control the processing no matter how many workstations are involved. There may be several groups of computers formed in one LAN processing the projects independently. Every group is synchronized using the control folder a dedicated shared folder on one of the computers, which must be accessible to all group members all the time the data is being processed (other computers may be turned on and off as desired). All the computers in the group must be granted read/write access to the share. Tasks for the processing are created using PHOTOMOD Mosaic (see the corresponding Manual). After the tasks have been created, they are automatically distributed between the computers involved. PHOTOMOD System Monitor is used to monitor the processing, change settings and manipulate tasks if necessary. Every task is executed by a separate instance of the PHOTOMOD Mosaic module, so it must be verified that there are enough of licenses for all the tasks running in parallel over the network. Also the essential condition for the processing is that all the computers in the group working with the same control folder use the same configuration of resource storages (see 7.2 Resources storage in PHOTOMOD system).

17.3.1 Tasks in queue

The Tasks in queue groupbox contains the toolbar and the summary table of the tasks. Each tasks has the following properties: ID a unique identifier of a task (is preserved when the task is completed and moved to the finished tasks list, see 16.3.3 Finished tasks). State task state: waiting to be executed, suspended, running (in this case the progress is shown). Pripority task priority (an integer number; the higher the number, the higher the priority; tasks with the highest priority are executed first). Name text string describing the task. For orthomosaic creation tasks PHOTOMOD Mosaic project name with the ordinal number of the task in the project. Type currently only one task type is available - mosaic
Created date and time of the task creation. Started for the running task date and time of the start. Executed by for the running task the name of the computer running it.
If a tasks fails execution on any of the computers in the network, it is highlighted in yellow. In this case, it will be attempted to execute by other computers. If no computer in the network is able to finish the task, it stays in the queue with Waiting state until it is deleted manually. To perform actions on a group of tasks, select it using clicking and dragging the mouse in the table. The following actions are available corresponding to the toolbar buttons: Button Action Refresh task list (when Auto refresh is off) Suspended selected tasks Activate selected tasks Increase priority of selected tasks Decrease priority of selected tasks Reset priority of selected tasks Reset error state of selected tasks and retry execution of the failed tasks Delete selected tasks Open the Finished tasks window (see 16.3.3 Finished tasks) Note. A running task cannot be suspended.

17.3.2 Computers

The Computers groupbox contains the list of computers which are currently online and configured for the same control folder (see 16.2 Initial setup). For every computer, it displays: Name the name of the computer in the network Tasks number of distributed processing tasks running on that computer CPU cores number the quantity of CPU cores for the computer Max tasks maximum number of simultaneous running tasks configured for the computer (see 16.2 Initial setup) PHOTOMOD build PHOTOMOD version build number for compatibility check. It is recommended to use the same PHOTOMOD build on all the computers in the group, though it is not a critical requirement. Computer name is highlighted in yellow if the computer is configured not to participate in the processing. The local computer name is displayed in green font. The following actions are available corresponding to the toolbar buttons: Button Action Refresh computers list (when Auto refresh is off) Setup the selected computer (see below) Do not use selected computers for distributed processing Use selected computers for distributed processing

To perform actions on a group of computers, select it using clicking and dragging the mouse in the table. When the row corresponding to the local computer is selected in the list, clicking the button brings up the dialog Distributed processing setup, see 16.2 Initial setup. When a row corresponding to a remote computer is selected in the list, clicking the button brings up the dialog Distributed processing setup for the remote computer:
This dialog allows modifying the parameters Maximum number of simultaneous processes and Use this computer for distributed processing (see 16.2 Initial setup) for the remote computer, name of which is displayed in the field Manage settings for computer with the remote remark. Note. All actions on the computers performed as described in this chapter, take effect with delay of up to 30 seconds.

17.3.3 Finished tasks

The Finished tasks window is brought up by clicking the button on the toolbar of the State monitoring window. It contains the list of successfully finished tasks. The tasks stay listed in this window until deleted manually (see below the description of the toolbar).
The tasks in the list have the same properties as the tasks in queue (see 16.3.1 Tasks in queue), and the following additional properties: Finished - date and time when the task was finished
Execution time - running time of the task
The following actions are available corresponding to the toolbar buttons: Button Action Refresh the list (there is no auto-refresh of this list) Delete selected tasks from the list Clear the list (delete all tasks) To perform actions on a group of tasks, select it using clicking and dragging the mouse in the table.

18. Acknowledgments

The routines for handling JPEG images use the source code from release VI of the Independent JPEG Group's software. The routines for handling TIFF use LibTIFF v. 3.8.2: Copyright (c) 1988-1996 Sam Leffler, Copyright (c) 1991-1996 Silicon Graphics, Inc. General purpose RX library was also used in the program development.

19. Glossary

A absolute orientation: see exterior orientation adaptive TIN: TIN created in a following way: in some neighboring area around the user defined rectangular grid node (with radius about 1/4 of grid cell size) the algorithm searches for the point with maximal contrast. Then correlation algorithm is applying to this point to calculate Z value and assign this value to the node. If the correlator fails in this point obtained (the correlation coefficient is less than the selected threshold value) the point is just ignored. The nodes calculated by adaptive model algorithm are triangulated considering the Delaunay criterion at further TIN creation and become its vertices. See also regular TIN, smooth TIN, TIN from vectors. aerial triangulation: the process of determining (x, y, z) ground coordinates of individual points, based on measurements taken from aerial photographs. Also known as triangulation or phototriangulation. See also block adjustment anaglyph glasses: special glasses with red and blue filters used to see the anaglyph stereo picture on the monitor anaglyph stereomode: anaglyph stereo picture is formed by visualization of the left and right images of the stereopair beyond red and blue filters on the screen. attribute: the tabular information associated with vector objects of selected code in the code table. The attribute fields are included to the code table associated with a file of vector objects. additional attributes: the tabular information associated with an instance of vector object. The additional attribute table is created for each vector object and is not linked to the code table. B Bezier: a smooth curve calculated based on four points of the source polyline using cubic equation. bilinear interpolation: a resampling method that uses the data file values of four pixels in a 2 by 2 window to calculate an output data file value by computing a weighted average of the input data file values with a bilinear function. PHOTOMOD uses the bilinear interpolation while transforming to epipolar images and orthorectification block: a group of images arranged in a more-or-less rectangular pattern collected from several parallel flight runs. The aerial block consists of several strips with a 20-30 percent overlap

different countries. All geolocations (i.e., the lat/long/elevation of a ground control points) make sense only when related to a datum. Sometimes it is useful to utilize two separate datum: a horizontal datum for the XY measurements, and a vertical datum for the Z measurements. Delaunay criterion: the technique used to generate the TIN, known as Delaunay triangulation, produces a set of triangles that are as equi-angular as possible. All circumcircles of Delaunay triangles contain no points other than the three that define the triangle and its circumference. Digital Elevation Model (DEM): digital cartographic representation of terrain elevations for ground positions at regularly spaced intervals. See also DTM, TIN. Digital Terrain Model (DTM): digital cartographic representation of terrain surface whether as a regular grid of elevation values (DEM) or an irregular network of triangles (TIN). E edge: an edge of a triangle included to the TIN ellipsoid: a figure created by an ellipse rotated about its shorter axis. In the context of map projections, an Earth ellipsoid has defined size and location in the Earth body and is considered as an auxiliary mathematical surface, to which all geodetic measurements are referred and on which stations of geodetic network are thus projected. Topographic survey and derived maps are also referred to ellipsoid surface. See also Datum. epipolar images: images of the stereopair resampled in such a way that they have only X parallax and the Y parallax is 0. Epipolar images are used for stereo viewing and measuring. epipolar transformation: resampling source images of the stereopair to epipolar images export: an operation of converting raster, vector and DTM data from PHOTOMOD to popular raster and vector formats. exterior orientation: a process of calculating exterior orientation parameters for each image of the block exterior orientation parameters: a set of values that describes the cameras position in space (x, y, z), and its orientation (, , ). Omega () describes the degree of rotation around the x-axis, phi () around the y-axis, and kappa () around the z-axis. The exterior orientation parameters are computed for every block image while the block adjustment process.
F fixed marker, moving image mode: in case of fixed marker it is located in the middle of screen all the time and its X parallax is equal to 0. While the vectorization you move the images of stereopair fixed image, moving marker mode: in case of moving marker you move it along XYZ axes while the vectorization and the underlying image is fixed on the screen (unless it is scrolled) focal length: the orthogonal distance from the projection center to the image plane of the camera. The focal length is computed while the camera calibration process and used in the interior orientation G gamma-correction: a method of the radiometric enhancement of dark or bleached out images geodetic coordinates: system of geographic coordinates where latitude and longitude are defined using results of geodetic measurements of angles and distances on the Earth surface, referred to some reference-ellipsoid. Geodetic coordinates (B, L, H) include not only latitude and longitude of the Earth surface point but also its height. See also pixel coordinates. geoid: the Earth figure bordered by the surface of gravitation potential, which coincides in oceans with average ocean level and continues under continents and islands so that it is perpendicular everywhere to earths gravity direction. Geoids surface is more smoothed than the Earths surface. Geoids shape has not accurate mathematical expression, and for map projections creating it is necessary to fit regular geometric figure which is close to geoid. The best geoids approximation is figure received at rotation of ellipse around its short axis (see ellipsoid). grid: regular grid with user-defined number of rows and columns and/or cell size used to build an adaptive or regular TIN ground control point (GCP): a point with known coordinates in the ground coordinate system. The error on GCPs is a main criterion of the block adjustment accuracy. See also check points, tie points. ground coordinates: see geodetic coordinates H I image: an aerial or satellite image (analogue, digital or digitized) used in photogrammetric processing. See also raster.

image resolution: an image cell size after scanning usually expressed in micrometers. Also known as scanning resolution. image ground resolution: an image cell size on the ground usually expressed in meters. images overlapping: an overlapping between adjacent images along the strip, usually should be about 60% for stereoprocessing import: an operation of converting raster, vector and DTM data from popular raster and vector formats to PHOTOMOD format interior orientation: the process of computing a transformation from film coordinate system to image coordinate system that accounts for the position and orientation of the photo when it is digitized. interior orientation parameters: a set of camera parameters including principal point coordinates, focal length and distortion coefficients calculated while the camera calibration process and used for the interior orientation interlace stereo mode: viewing a stereopair in such a way that the left image and the right image are displayed in the odd and even screen lines, or vice versa by using the special LCD shutter glasses. See also anaglyph stereo and page flipping stereo. inversion: a conversion of grayscale image from black-white to white-black J K L layer: a display entity comprised of one or more components that can be manipulated separately from other layers. Dividing 3D vector objects into layers are useful in order to separate different types of objects. Thus hydrology objects may be put into one layer and roads into another one. Besides vector objects all other kinds of objects such as DEM, TIN or raster image are also layers. left-handed coordinate system: a coordinate system that has an X axis directed to the north and Y axis directed to the east. Left-handed coordinate systems are widely used in Russia and many former socialist countries. See also right-handed coordinate system lens distortion: set of values or coefficients that describe image distortions caused by the camera lens. Distortion coefficients are computed while the camera calibration process and used in the interior orientation.
local coordinate system: a rectangular coordinate system that considers the Earth surface as a sphere of fixed radius. See also Cartesian coordinate system, coordinate system local region: 3D vector polygons dividing the TIN creating area into regions in order to use different TIN creation algorithms for each of them. Thus you can bound an area of the village by local region and create TIN by vectors in it and build adaptive TIN for the rest of the stereopair. M map: a cartographic representation of spatial relationships on the earth, other planets, or the geographic milieu (both theoretical and technological). map projection: mathematic method of representing the three-dimensional spherical surface of a planet on a two-dimensional map surface. Map projection sets analytical dependence between geographic coordinates of points on the Earth ellipsoid and rectangular coordinates of the same points on the flattened surface. See also ellipsoid, geoid. map symbol library: a set of symbols and patterns used to display point, line and polygon vector objects on the map. There are several map symbol libraries available in PHOTOMOD system corresponding to the maps of different scales and included to classifiers. marker: a special screen cursor used for stereo viewing, measuring and digitizing. Marker is displayed on both left and right images of the stereopair. Also mentioned as a stereomarker. marker = mouse: a mode when the mouse cursor disappears from the screen and all mouse related actions affect the corresponding behavior of the stereomarker. The mode is useful for 3D vectorization since you have only a stereomarker on the screen. mono mode: a mode of mono image viewing. In this case you should use the snap-to-ground mode to calculate Z coordinate of objects automatically. N node: 1. a TIN node (an element of the TIN along with the edge and the triangle) 2. start and end point of each 3D vector line (polygon) 3. common point for several vector lines (polygons). See also vertex. O object: see vector object. orthoimage: an aerial photo or satellite image that has been processed to remove perspective distortions and so to have the properties of an orthographic projection. Distortions of

S scanner image: a satellite image acquired by a pushbroom scanner (SPOT, IKONOS, IRS, etc) or whiskbroom scanner (Landsat) scanning: digitizing source photo materials (films, prints etc) in order to create a digital image raster scanning resolution: a resolution of raster image defined when scanning expressed in micrometers or dpi (dots per inch) segment: a straight fragment of a polyline between its two vertices sensor independent mode: general mode of scanner images processing. Using this mode you can work with any pushbroom scanner images without taking into account specific properties of each sensor and orbital parameters. There are also several special modes of working with specified sensors in PHOTOMOD (SPOT). These specific modes need less ground control points and produce higher accuracy. shutter glasses: LCD glasses attached to the video card and synchronized with a monitor vertical frequency. Shutter glasses are used in PHOTOMOD for stereo-measurements in interlace and page-flipping modes. smooth TIN: a TIN creation algorithm using a set of 3D points to create a polynomial surface. The regular grid of pre-defined resolution is projected on this surface in order to calculate Z values in each node. The smooth TIN is built99 by triangulating the grid nodes. See also adaptive TIN, regular TIN, TIN by vectors. smoothing: an operation of smoothing vector lines consisting of straight segments by using Bezier curves. Smoothing operation is basically used for contour lines. snapping: an automatic spatial attaching of the marker to vector objects on the screen. Snap mode is useful when you need spatial coincidence of creating object elements with the existing ones (for example when digitizing a power line through its previously digitized piers) snap to ground: a tool of automatic projection of the marker on the ground (the stereo model surface). Snap to ground mode uses the correlator for marker positioning by Z axis along with manual marker moving in XY plane. stereomarker: see marker
stereopair: a pair of images with an overlapping area (for airborne survey is usually about 60 percent), obtained from different points. strip: a set of images captured along a flight-line, normally with an overlap of 60% for stereo coverage. All photos in the strip are assumed to be taken at approximately the same flying height and with a constant distance between exposure stations. strips overlapping: overlapping between adjacent strips of images, for airborne survey is usually 20-30%. T targeted point: a tie point located on the well recognized ground feature. The targeted point coordinates are calculated by the block adjustment procedure so it can be used as a ground control point in further photogrammetric processing. tie point: an image point located on a common feature, such as a road intersection in two or more overlapping images and used in the block adjustment process for tying images. See also check point and ground control point. triangulation points: all points (ground control, check and tie) that are involved in aerial triangulation process. TIN (Triangulated irregular network): a surface representation derived from irregularly spaced points and breakline features. The TIN data set includes topological relationships between points and their neighboring triangles. Each sample point has an x, y coordinate and a surface, or zvalue. These points are connected by edges to form a set of non-overlapping triangles used to represent the surface. TINs are also called irregular triangular mesh or irregular triangular surface model. TIN by vectors: a TIN created by direct triangulation of 3D vector objects: vertices and points becomes TIN nodes and segments becomes TIN edges. See also adaptive TIN, regular TIN, smooth TIN. TIN optimization: an operation of TIN restructuring in order to satisfy Delaunay criterion. TIN by local regions: a TIN created as a mosaic of TINs built in each local region using different strategies. topology: a description of spatial relationships of 3D vector objects triangle: a TIN triangle (an element of the TIN along with the edge and the node) triangulation: see aerial triangulation

U uncertain nodes: TIN filtering operation is looking for potentially erroneous TIN nodes (some peaks on TIN surface). Such nodes are marked and called uncertain nodes. V vectorization: a process of manual or semi-automatic ground feature extraction from stereo raster image in vector format vector map: a digital map consisting of vector objects vector object: 2D or 3D vector point, polyline or polygon etc vertex: the point at which a polyline or polygon changes direction or terminates W whiskbroom scanner: also referred to as across-track scanner. It uses rotating mirrors to scan the landscape below from side to side perpendicular to the direction of the sensor platform, like a whiskbroom. The width of the sweep is referred to as the sensor swath. The rotating mirrors redirect the reflected light to a point where a single or just a few sensor detectors are grouped together. Whiskbroom scanners with their moving mirrors tend to be large and complex to build. The moving mirrors create spatial distortions that must be corrected with preprocessing by the data provider before image data are delivered to the user. An advantage of whiskbroom scanners is that they have fewer sensor detectors to keep calibrated as compared to other types of sensors. Installed for example on Landsat 7 satellite. PHOTOMOD system contains special sensor independent mode to process whiskbroom scanner images. See also pushbroom scanner. X X - parallax: the difference between the image coordinates of a point in each image of a stereo pair along X dimension Y Y - parallax: the difference between the image coordinates of a point in each image of a stereo pair along Y dimension Y - parallax error (residual vertical parallax): the quality of measured points is checked using the residual vertical parallaxes and the discrepancies in tie points coordinates calculated in the procedure of tying of two adjacent models. Z
1, 2, 3 3D vector object: see vector object