Tutorial - Lesson 1 - SPRING General View

The topics presented here are:

Lessons Summary


1. Systems Presentation

The SPRING (Georeferencing Information Processing System) product is a geographic database of 2º generation, for UNIX and Windows environments with the following features:

  • Works as a geographic database without boundaries, supporting a large data volume (without scale limitations, projections or time zone), keeping the geographic objects identity throughout the database;
  • Manages both, vector and raster data, and performs Remote Sensing data integration in a GIS;
  • Gives a friendly and powerful environment through a combination of menus and windows with a spatial programming language easy to learn (LEGAL - Space-Geographic Language based on Algebra).;
  • Gets complete scalability, that is, it is capable to work with full capabilities (Windows and Linux).

The SPRING is based on an object oriented data model. Its menus and spatial language LEGAL interface were designed based on the same objects. New algorithms, such as the one used for spatial indexing, image segmentation and triangular grid generation, give the required performance for a variety of applications. The SPRING was designed for the RISC architecture and the OSF Motif standard graphical interface. The SPRING presents a very friendly and interactive interface, besides, it has on-line documentation, both written in portuguese, facts that help the system usage and the user support.

Another feature, considered extremely important, is that the database is unique, that is, the data structure is the same, no matter if the user works in a micro computer (IBM-PC) or if the user works in a RISC workstation, without data conversion. The same happens with the interface, which is exactly the same, thus, there is no difference about the SPRING operation.

Based on these features the SPRING has been a very attractive package in the geoprocessing field as a shareware. It can be downloaded from the Internet ( "http://www.dpi.inpe.br/spring" ), just register in the SPRING home page.

The SPRING is a product developed with Brazilian technology, completely implemented in the Brazilian Institute for Space Research - INPE , in São José dos Campos, São Paulo, a city known by the companies and institutes working with technology, mainly in the airspace field.

Lessons Topics


2. SPRING Database

A SPRING database corresponds, physically, to a directory where the Classes and Categories definitions will be stored, as well as the database projects. The projects are stored in sub directories together with data files: points, lines, orbital and aerial images, thematic images, texts, grids and objects.

Only the current user (the one logged in) can activate a Database if he/she has read permission, and only one database can be active in a working section.

NOTE: A database is activated automatically every time that the SPRING system is loaded, always the last database used in the last section, or a different database defined in the Environment Setup window.

The next figure shows the Database structure in the SPRING. Notice that any geographic data is represented by a Geo-field or a Geo-Object:

hierarquia_db.gif - 4027 Bytes

    Geo-field : "A geo-field represents a spatial distribution of a variable that has values in all points representing a geographic region." The geo-fields can be specialized in:

    • THEMATIC: Given a geographic region R, a thematic geo-field associates to each point in space a theme in a map (e.g. a pedology map is characterized by the set {Dusky-Red latosoil, litosoil, cambisol, ...}).
    • NUMERIC: Given a geographic region, a numerical geo-field associates, to each point in space, a real value (e.g. a magnetic field map);
    • IMAGE: Given a geographic region, it is obtained by discretization of the answer received by a sensor (active or passive) for all the region points. See the figure below.
    imagem_tm_manaus.gif - 35467 Bytes

    Geo-Objects : "A geo-object is a unique element that has non-spatial attributes and is associated to multiple geographic localizations. The location intended to be exact and the goal is distinguishable of its contour." Each geo-object is associated to one or more regions (or locations) in space. For instance in a map of urban registers, lots in the same neighborhood are stored and presented in a set (see the next figure).

    esquema_geobjeto.gif - 9668 Bytes

Activating a database:

    - # Start - Programs - Spring - Spring( windows.gif - 1353 Bytes ) #spring ( unix.gif - 943 Bytes )
    - [File] [Database...] or button

      Database
      - (Database | Course)
      - (Load) - Answer Yes if there is other Database/Project active.
      * In the main window of the SPRING module all functions are reached by the menu bar, or the tools bar (for version windows.gif - 1353 Bytes ).

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3. SPRING Data Model

Before the introduction of any data in the SPRING it is required to create/define the Data Model of the active database, because any information has to belong to a Category (a unique Model) that is: Thematic, Numeric, Image, Network, Cadastral or Object . The data graphical presentation characteristics (Visualization of areas, lines, points and texts) are also defined and stored together with the Database model.

The user does not need to define all the categories at once, because many times it is not known everything required to reach the goal. At any moment it is possible to add or define new categories. Only the categories for the Thematic model are divided into Thematic Classes, and each class can have a different visual features, for instance:different colors for each soil type .


Analyze the Data Model of the "Course" Database:
- [File] [Data Model...] or button

    Data Model
    - (Categories | TM_Image)
    - (Categories | Altimetry)
    - (Categories |Land_Use)
    * Notice that each category belongs to one of the models. Only the thematic category is divided into classes.
    - (Thematic Classes | Savannah)
    - (Visual...)

      Graphical Presentation - Visual Aspects
      - (Areas | SOLID, PATTERNS, etc..)
      - (Color...)

        Color Selection
        - Select one color
        - (OK)

      * See the visual aspects for Lines, Points and Texts.
      - (Close)

    Data Model
    - (Close)


NOTE : When changing the visual aspects of a class for any geographic entity, representing in one or more IL's in the same or in another Project, inside the same database, they will be changed accordingly.

Lesson Topics


4. Projects

A project really defines the physical working area. It has to give a name, projection and bounding box to create a project. A sub-directory, below the database corresponding directory, will be created, and all data related to a given region will be stored in this directory. It is possible to have as many projects as one wishes, but only one has to be active at once.

A Project can have a set of Information Layers (ILs), where these ILs have the same projection system . The original data from other projection systems, will be always remapped for the projection used in the project during the importing process or data input. That is why it is important to define a system adequate with data scale, anticipating also the cartographic products that will be generated.

NOTE: A project inside a database is automatically activated after it has been opened in another section. The Spring stores the last project opened before exiting the system, or a determined project defined by the Environment Configuration window.


Activating a Project:
- [File] [Project...] or button

    Projects
    - (Projects | Brasilia)
    - (Projection...)

      Projection
      - (Systems | UTM)
      * Notice that it is possible to select one among thirteen projections. Depending on the choice other parameters have to be defined as Hemisphere, Source Latitude and/or Longitude and Standard Parallels;
      - (Close)

    Projects
    - (Coordinates <=> Planes or Geographic)
    * Notice that a project can be defined in Plane coordinates (meters) or Geographic (degree, minute and second).
    - (Load)

NOTE : The "Control Panel" window is presented to the user together with the Spring main window when a project is activated, and it is in this window that the data selection and window visualization control happen.

Lesson Topics


5. IL's Visualization

It is the Control Panel that the Information Layers and its different representations are selected either for visualization or for the desired operation.

To select an IL over which any operation has to be performed, it is first required to activate it, or even, depending on the operation it is required to present it in the active window. Thus use both lists from the Control Panel: Categories and Information Layers .

  • Categories - the categories presented are the ones in the active Database, which has at least an Information Layer in the active project. According to the category, the IL's are presented and its available representations. The parentheses "( )" with the category will be filled with (V) when any information of that category is selected.
  • Information Layers - they are presented according to a Category selected above. Below the IL's list there are the representations available for the Information Layer selected.

When selecting an Information Layer (IL) the options to apply in the IL in the menu bar will be available in the main window. Depending on the operation it is not required a data visualization, only the selection is enough to perform over the active IL.


Visualizing a monochromatic image in the main window:
- [View] [Control Panel] or button

    Control Panel
    - (Categories | TM_Image)
    - (Information Layer | TM5)
    - (M) to visualize in gray levels. Observe if the IL is selected.
    SPRING
    - [Execute] [Draw] or button
    Control Panel
    - (Show<=> Display 2)
    - (Enable<=> Display 2)
    - (Categories | TM_Image)
    - (Information Layer | Highlight_TM5)
    - (M) to visualize in gray levels.
    SPRING- Window 2 - [Execute] [Draw] or button
    * Compare the two images. In display 1 the original image is presented and in Display 2 the highlighted image.

Visualizing an aerial picture in the main window

    Control Panel
    - (Enable <=> Display 1)
    - (Categories | photo_Image)
    - (Information Layer | Photo 1)
    - (M) to visualize in gray levels. Observe if the IL is selected.
    SPRING - [Execute] [Draw] or button atalho_desenhar.gif - 941 Bytes
    * Note that the image covers an area (evolving rectangle) smaller than the previous image, but with a higher resolution.


Visualizing a synthetic image in the main window

    Control Panel
    - (Categories | TM_Image)
    - (Information Layer | Comp_3B_4R_5G)
    - (Synthetic Image) to visualize a color image. Observe if the IL is selected.
    SPRING
    - [Execute] [Draw] or button
    * In this image the pixels are associated to a color table.


Visualizing a Colored Composite (RGB) in the main window

    Control Panel
    - (Categories | TM_Image)
    - (Information Layer | Highlight_TM3)
    - (R) to visualize an IL in the red LUT.
    - (Information Layer | Highlight_TM4)
    - (G) to visualize an IL in the green LUT.
    - (Information Layer | Highlight_TM5)
    - (B) to visualize an IL in the blue LUT.
    SPRING
    - [Execute] [Draw] or button
    * In this image the pixels of each monochromatic band is associated to a LUT (RGB primary colors cannon).
    * Try to make another composition, for instance: Highlight_TM3 in B, Highlight_TM4 in R and Highlight_TM5 in G.


NOTE: Besides Display 1 represented by the main window in the "Spring" module, there are other 4 Displays available for visualization, number 2, 3, 4 and 5. The Display 5 is specially reserved for registration of images which have to be fixed. This control of display is done at the "Display Control" inside the "Control Panel" .

Zooming the Drawing Area

    Once there is one or more ILs drawn in any of the five windows, it is possible to amplify through another window, whatever is seen in a window. In the "Control Panel" use the buttons Zoom to amplify 2, 4 or 8 times the data in the drawing area. Move the cursor over one of the windows and the cursor position will be amplified, according to the selected option.

    NOTE : This zoom resource is really useful when one wants to localize control points with higher precision in the registration process in an image.

    tela-zoom.gif - 112991 Bytes

    Zoom Cursor

    The Zoom Cursor (zoom) is used to define regions to be amplified in the drawing areas. The zoom is enabled when this button is active or the mouse has a small square shape ( in ) or an arrow pointing to a lower right corner ( in ) inside the drawing area. Two points are required to establish the zoom area, the upper left corner and the lower right corner.

    The procedure to make a zoom requires 4 main steps:

    Þ Making a zoom in the drawing area:

    1. activate the Zoom Cursor in [View] [Zoom Cursor] or . Notice that the cursor changes from the normal mode (upward arrow) to the zoom mode ( in or in );
    2. click using the cursor in the drawing area to define the first point (upper left). Notice that the cursor changes to an arrow pointing down (only in the UNIX version), indicating that the movement has to be from left to right and from top to bottom. Drag the cursor up to the desired point;
    3. click again to define the second point (lower right corner) in the zoom area;
    4. click on - [Execute] [Draw] or button .

    NOTE: To disable the zoom cursor and return to the normal mode, just click on the Point Cursor in the tools bar or [View][Zoom Cursor], or the middle right button (RB) inside the drawing area.

    Once a zoom area is defined (dashed rectangle) this can be adjusted, before the [Execute] [Draw]. Clicking on any of the rectangle side lines or external diagonals, allow to redefine the rectangle's size (see the eight possible positions in the figure below). A second click is required to anchor a new position.

    cantos_do_zoom.gif - 2583 Bytes

    The marked zoom area can be totally moved to another position, just click on the internal part of the defined rectangle, drag the rectangle to a new position and click again to anchor the new position.

Visualization Window

    The visualization windows or drawing areas are controlled in the "Control Panel ", the window position in the screen and the data being presented. Next the windows facilities will be presented.

    In the windows footnote area, just below the drawing area, presents a message to the right, indicating which is the active information layer, that is, the IL over which the operation will be performed even if the IL is not visualized in the window, and to the left, it shows the planes or geographic coordinates of the cursor position, in case it is enabled.

    To know what IL's are selected for visualization in that window just activate the corresponding window in the "Control Panel " and the (V) marks between parentheses in the Categories and IL's indicating which IL's and representations are selected.


Auto/Plain/Scale Mode

    The ILs presentation in the drawing area can be controlled by other parameters that are defined for each window. In the footnote of each window (version unix.gif - 943 Bytes ) or in the tools bar (version windows.gif - 1353 Bytes ) there is an options button that allows to select among: Auto, Full and Scale . See the effects of each of these options:

    • Auto Mode: the SPRING resample the image such that it is presented all inside the windows pattern dimensions, of the active project or like a rectangle defined for a zoom.
    • Full Mode: there is no resampling, all pixels are presented and if the image does not fit inside the window, the side bars can be used to visualize the whole image.
    • Scale Mode: the data will be presented in the window using the scale defined in the corresponding field, it requires only that the scale value is typed. A message will make an alert if there is not enough memory to zoom the image to the desired scale. In this case the scale factor should be reduced. The text box presenting the scale for each visualization can not be changed unless the Scale option is selected.

    NOTE: When clicking on [Execute] [Reset] or button in the active window, the presentation mode returns to the Auto mode.

Coordinates presentation

    Once the project is cartographically defined, it is possible to see in real time the cursor position, in planar or geographic coordinates, while it is moved over a drawing area.

    Use the options button Inactive/Plane/Geographic that is also in the footnote of each drawing area. (version unix.gif - 943 Bytes ) or in the tools bar (version windows.
gif - 1353 Bytes ). The coordinates are presented in the windows footnote, in meters for the Plane coordinates and in degrees, minutes and seconds for the Geographic coordinates. The Inactive option disables the coordinates display in the footnotes.

Draw, Reset and Previous

    The Drawing button or [Execute] [Draw] in the main menu updates the data in the window according to the selection done in the "Control Panel" and the presentation features, like scale, defined in the window. The button has to be activated at each new selection, after changing the visualization parameters, data editing and after defining the zoom area with the cursor.

    The Reset button or [Execute] [Reset] in the main menu resizes the data presentation as a function of the window size and the bounding box in the active project. It undoes a zoom performed by the Zoom Cursor and restores the presentation mode for Auto, in case it was set to Plain or Scale.

    The Previous button or [Execute] [Previous] in the main menu restores the last presentation action in a data in the current window. It undoes the last zoom performed by the Zoom Cursor or Roaming Cursor.

Flying over the drawing area

    The flying feature through the button or [View][Roaming Cursor] in the main menu, allows to move the data in the window keeping the visualization scale, and only has effect when a zoom is applied over the data in the active window. The cursor turns into a cross (+) when the flying resource is active. Click on a point in the window and drag the cursor up to the desired position, release the button next so the image will be presented in a new position. To restore the cursor as an arrow, click on the mouse right button inside a drawing area or in the flying button.

Lesson Topics


6. Exiting the SPRING

To exit the SPRING (specifically the "Spring" module) the user does not need to be concerned about saving the data, that is, the information layers that were edited, are automatically saved. Only auxiliary files such as: context files for a classification and control points for a register, requires a saving operation.

Exiting the SPRING:

    SPRING
    - [File] [Exit]
    * Select YES when asked if you really want to close the SPRING.

    * In the Windows version, the environmental variables SPRINGPROJ and SPRINGDB are updated when the system shuts down, making the last database and project active when the "Spring" is started again.

Lesson Topics

Lesson 1 - Summary

See also:
The SPRING Data Model
About the SPRING