Spatial Data Geographic Information System (GIS) using ArcGIS

Most of the data to be handled in a GIS is a spatial data is a geographic data-oriented, have a particular coordinate system as the basic reference and has two essential parts that make it different from other data, the location information (spatial) and descriptive information (attributes) that described below:

• Location information (spatial), corresponds to a coordinate either geographic coordinates (latitude and longitude) and the XYZ coordinates, including the datum and projection information.
• Descriptive information (attributes) or non-spatial information, a location that has some information related thereto, for example: type of vegetation, population, area, zip code, and so forth.

Format and Spatial Data Sources

In a simple format in the form of computer language and code storage means different data between files with one another. In GIS, spatial data can be represented in two formats, namely:

• Vector Data

Data vector is represented in the form of the earth into a collection of lines, area (the area bounded by a line that begins and ends at the same point), and point nodes (the point of intersection between two lines).

• Raster data

Raster data is the data generated from the system of Remote Sensing. On raster data, geographic object is represented as a grid cell structure called a pixel (picture element).

On raster data, the resolution (visual definition) depends on its pixel size. In other words, describe the size of the actual pixel resolution in the earth's surface represented by each pixel in the image. The smaller the size of the Earth's surface is represented by a single cell, the higher the resolution. Raster data is very good to represent the limits of the change gradually, such as soil type, soil moisture, vegetation, soil temperature and so on. The main limitation of raster data is the large size of the file; the higher its resolution grid, the greater the file size and highly dependent on the hardware available Capacity.

SIG is one of the requirements of spatial data, which can be obtained from several sources, among others:

• Analog map

Analog maps (including topographic maps, soil maps, etc.) that maps in printed form. In general, analog maps made ​​with cartographic techniques, are likely to have such a reference spatial coordinates, scale, cardinal directions and so forth. In stages as the purposes of GIS data sources, map analog converted to digital maps in raster format to be converted into vector format via dijitasi process so as to show the actual coordinates on the surface of the earth.

• Remote Sensing Data Systems

Remote Sensing Data (such as satellite imagery, aerial photographs and so on), is the most important data sources for GIS because ketersediaanya periodically and cover a specific area. With a variety of satellites in space with their respective specifications, we can obtain various types of satellite imagery for various purposes of use. This data is usually represented in raster format.

• Field Measurement Results Data

Field measurement data generated by a separate calculation technique, in general, this data is a source of attribute data eg administrative boundaries, land ownership boundaries, parcel boundaries, limits of forest concessions and others.

• Data GPS (Global Positioning System)

GPS technology provides an important breakthrough in providing data for GIS. The higher the accuracy of GPS measurements to the development of technology. This data is usually represented in vector format. Discussion of the GPS will be explained hereinafter.

Data Acquisition Method / Geographic Information

1. Field survey: physical measurement (land marks), sampling (water pollution), non-physical data collection (data social, political, economic and cultural).
2. Census: the approach of questionnaires, interviews and observations; national data collection and periodic (census population, census of land holdings).
3. Statistics: the periodic method of data collection / per-interval-time at the station of observation and analysis of the geographic data, eg rainfall data.
4. Tracking: a way of collecting data in a particular period for purposes of monitoring or observation of the changes, eg, forest fires, volcanic eruptions, river water discharge.
5. Remote sensing (remote sensing): a science and art to obtain information of an object, area or phenomenon through the analysis of sensor data obtained from observers without direct contact with the object, area or phenomenon observed

More about → Spatial Data Geographic Information System (GIS) using ArcGIS

FEATURING GEO LINK TO IMAGE IN ER Mapper 7

In the ER Mapper application, the term means GeoLink make connections between two or more images in a different window. GeoLink mode should be in the same projection system. ER Mapper provides GeoLink modes include: Window mode is the relationship of two or more different image in the display window on the windows the same extent.

Screen Mode is the relationship between the image where the image as a master, while the other image relative to him.

a. GeoLink to Window

GeoLink to window provides an easy to observe some of the images that have the same coverage area, or nearly the same at the same time in separate windows, but with the same scale.

• To provide first started, two different image data in the same projection system (eg landsat_indonesia.ecw and pangrango_001_geo.ecw)
• Open a new window by clicking the open fi twice to display two windows
• Click to load the data (Landsat indonesia.ecw) the unity window, and click to load the data (pangrango_001_geo.ecw).

• For the window to one and the second window, right-click and then click Quick Zoom | Set GeoLink to Window to create a window mode.

• Two windows are connected to each other, and the addition can be done to make GeoLink window window as much as possible.

b. GeoLink to Screen

GeoLink GeoLink to Screen is a system in which one image is displayed with a particular viewing position, while the other images will have the same position and tied with the first image window. So GeoLink to screen this will have a display as an overlay, but with separate layers for different window for each image.

• To provide first started, two different image data in the same projection system (eg landsat_indonesia.ecw and pangrango_001_geo.ecw)
• Open a new window by clicking the open fi twice to display two windows
• Click to load the data (Landsat indonesia.ecw) the unity window, and click to load the data (pangrango_001_geo.ecw).

• For the window to one and the second window, right-click and then click Quick Zoom | Set GeoLink to Screen for making screen mode.

• Two windows are connected to each other, and can be done to make GeoLink addition of window screen as much as possible.

Overlay and Algorithms

Algorithm is the basic building within ER Mapper algorithm stores all the information necessary to display the data as an image. The information stored in an algorithm includes a data source, the colors used for display, data processing steps in detail. An algorithm is a revolutionary concept that separates the data from data processing. All data integration, data processing options other files contained in the algorithm. All this is created and edited by ER Mapper, ER Mapper which contain different types of data processing algorithms.

• Please open the file that has been available (eg Landsat indonesia.ecw)
• Open the window by clicking the algorithm (RGB): RGB, so the image appears like this

• Click the button text [RGB] RGB to activate the layer file
• Click the paste to duplicate the layer so that the display becomes as shown below

• Click on the topmost layer (as shown in the figure above) then click the blue layer to loading new data, and select the file you want the dioverlay (eg pangrango_001_geo.ecw).
• Storing files in the. Alx, for example, is stored with the name citra1.alg.
• To open the algorithm, from the menu bar select File, then select Open, select the name of the algorithm are shown.

TWO IMAGE mosaic

• Open the two images in a different window so as to produce images like this

• On one of the select window, window display lights up blue. Then click the [RGB] RGB to open the display algorithm.
• Activate the text [RGB] RGB and the new window click to copy the file layer.
• Then turn on the only window, and click the [RGB] RGB to display algorithm.
• Click the paste icon to paste the previous file layer, and zoom all datasets
• Will appear as below

• Do file storage, can be in the form. ALG, res, tiff, or ECw.

Or can also use the following steps:

• Make sure the file you want to dimosaik be in one folder and have the same projection system.
• Click blur (image display and mosaic wizard) on the ER Mapper window.
• Enter any of the files that will dimosaik by clicking open the file and activate the Mosaic all files of this type and Manually set mosaic method.


 
• Click Next to move on.
• - Enable Cell sizes, Types of data, Number of bands, and Coordinate Systems. Then click Next to start the process.





Mosaic results will appear after it is complete.

• If you want to vary the file to be in the mosaic, mosaic type, or otherwise, click on the option that appears to repeat the process.
 
• Click Finish to close the dialog box.

View Map / image in the mosaic and map / image of the mosaic

More about → FEATURING GEO LINK TO IMAGE IN ER Mapper 7

FEATURING ON IMAGE TO MONITOR

• From the menu bar select File / New to create a blank display or click New
• From the menu bar select View / Algorithm, to display the contents of the algorithms of the Window, or view previously created.
• Algorithm box will appear and a new Window boxes as follows:

• In the image window box there is written Algorithm Not Yet Saved ***

In the box there is no image because there is no image file is entered *** Signs show window / box is currently active or being elected, the number 3 indicates that the window box is first opened the box, this figure will increase by the amount of window boxes opened so that when we opened the box to the 15 it will display the number 15 on the display. Algorithm Not Yet Saved writing means that we open the display window is not already stored in the algorithm file (. ALG).

• From the menu click on the image above algorithm under No word dataset to load the data to be displayed.
• Will come out a new look, a box Raster Dataset

• Then select Data are shown mean we select the highlighted file and the box will close the Raster Dataset. . means we choose the file that the higlight and the box will not close the raster dataset. This Layer Only the phrase that follows the word OK and Apply tersebuut indicates that the command affects only the selected layer only but not for all the layers. is the command to show information from the dataset file which we will choose.

• When the data is original data, then the cell size x and y will be worth 1 meters. This value should we change the subject to Landsat-TM spatial resolution of 30 meters, ie by clicking Then it will appear :

• Then click on the new box will appear

• Then click on the new box will appear

• Fill in the option value of 30 X Dimension and Y dimension as the example above, then click OK.
• Click Yes if there is a statement Save changes before closing the editor?
• The values ​​of x and y cell size will change to 30 meters, and then click Cancel
• After you select a data file, and then we determine what the layer will display the data. When you have selected, then the file name will appear on the city's algorithm.
shows the active layer and the selected file will be displayed on the proficiency level layer (the example above shows one band as the selected layer). By clicking the down arrow beside the text B1: Band 1 then it will appear around the layer that is on file (in this case is 7 iini band of Landsat-TM) as the example above.



• Set the type layer to be used to display data that has been loaded, multiple layer options provided are Pseudo, Red, Green, Blue, Intensity, Height, and others. To find out the type of layer can by right-clicking on the sentence Pseudo Layer.
• Signs • indicate the type layer selected.
• To display a combination of channel 542 for example, then make three layers, namely Red, Green, and Blue.
• To show the classification results, it is made Class Display layer.
• To display the Color Pseudo, Pseudo layer is made


Note:
• To change the type layer right click on the layer to be replaced.
• To mengduplikasi click Duplicate layer or layer copy then paste layer
• To remove the layer click the layer cut
• To turn off the layer, right click and then select Turn Off or click
• Image and to raise and lower level layer.

More about → FEATURING ON IMAGE TO MONITOR

TUTORIAL SOFTWARE ER Mapper 7.x

Activate ER Mapper Software Ver. 7.x

• From the Windows XP or Windows 98/NT/2000 disable / close all other programs that are performing well and disable the screen saver program so as not to interrupt the work process to be performed.
• From the Start menu select Programs and then select ER Mapper 7.x, then the image will appear as follows:

• Select Run ER Mapper in Evaluation Mode when we do not have a Permanent License on the Software. Wizard will not appear when the permanent License Mapper ER has been held on a computer is concerned.

• Or from a desktop computer can be searched shortcut icon as shown below, then click two times, so also will display a menu like the one above.

Figure: Schematic satellite image processing tool using ER Mapper software

ERMAPPER application has 3 (three) windows / main window which is used to perform image processing in digital, that is the main window (Ermapper window), window image (image window) and window algorithm (algorithm window).

Er Mapper 7.0 Main Window

Display window Er Mapper 7.0

Window algorithm Er Mapper 7.0

Through the main window we can do and bring a variety of modules which are provided for image processing. All the image manipulation process, both formulas, filtering, preparation of composite and the other is displayed in the window algorithm. So we can say that this store window algorithm formulas that we do image processing. We can also do the editing of the image manipulation process through the window of this algorithm. The results of image manipulation will be displayed in the image window.

In the image window, there are several menus that can be run by right-clicking the mouse on the image window.

There are 5 groups of the menu that appears, namely:

Processing menu:

•       Stop Processing (ESC), is used to interrupt the ongoing image.

•       Image Refresh (F5), used to repeat the process of re-appearance of the image.

•       Clip, a sharpening of the display image based on pixel values ​​that appear in the coverage area of ​​the image window. Sharpening is done by stretching the contrast based on the minimum and maximum pixel values ​​of coverage are shown.

Zoom menu:

•       Previous Zoom, used to display images with the look as before.

•       Zoom In, rear view

•       Zoom Out, shrink the display

•       Zoom to All Datasets, to zoom to the entire dataset area / surface are shown.

•       Zoom to Current Dataset, zoom on area of ​​coverage of the dataset (layer / surface) were selected.

•       Zoom to All Raster (Vector) Datasets, to zoom to the entire raster data (vector) are shown.

•       Extent Zoom to Page, zoom into an area the size of paper used (depending on its setup page).

•       Zoom to Page Content, zooming in on the contents of the map layout.

•       Set GeoLink to None, remove GeoLink image window.

•       Set GeoLink to Window (Screen / Overview Zoom / Overview Roam), set the image window to window geoling another image.

File menu:

Group menu contains standard menus are also available on the main window Ermapper.

Pointer menu:

These menus are used to change the mouse cursor functions:

•       Hand, used for shifting the display image.

•       Zoom, used to enlarge or shrink the image display by clicking the left mouse  drag down to raise or up to down.

•       Zoom Box tool, used to zoom on a particular area in accordance with the desire to give depth to an area of ​​the box area in the area to be enlarged.

•       Pointer

Ø  Information menu:

•       Algorithm, is used to display the window algorithm.

•       Cell Value Profile, to display the pixel value information window.

•       Cell Coordinate, to display the information window coordinates.

Ermapper can display multiple image windows at once, but it only shows one window algorithm. The algorithms presented is an algorithm of the currently active window image or active the last time.

Surface    : can be said as a dataset, in which a single surface can consist of one or more                   layers. There are several types to choose from a surface, namely Pseudocolor, Red 

Green Blue or Hue Saturation Intensity. 

Layer : can only be on the surface, and can only display one channel only. 

Current surface / layer: a layer / surface is highlighted (highlight), the layer is currently active / 

selected for further processing if we do a copy, duplicate, move up / down or turn off / on. 

Invalid layer : the layer that does not correspond to the selected type of surface 

(pseudocolor, RGB or HSI). This layer will be displayed with a red cross and will not appear in the image window. 

Off layer : the layer is not active, so it does not appear in the image window. 

Surface : can be said as a dataset, in which a single surface can consist of one or more layers. 

There are several types to choose from a surface, namely Pseudocolor, Red Green Blue 

or Hue Saturation Intensity. 

Layer : can only be on the surface, and can only display one channel only. 

Current surface / layer : a layer / surface is highlighted (highlight), the layer is currently active / selected for further processing if we do a copy, duplicate, move up / down or turn off / on. 

Invalid layer : the layer that does not correspond to the selected type of surface 

(pseudocolor, RGB or HSI). This layer will be displayed with a red cross and will not appear in the image window. 

Off layer : the layer is not active, so it does not appear in the image window.

More about → TUTORIAL SOFTWARE ER Mapper 7.x

Satellite Remote Sensing Image

Satellite remote sensing imagery is a 2-dimensional (2D) describing an object from view. Satellite remote sensing imagery depicts part of the Earth's surface that look of a room.

1 Digital and Analog image

The image can take the form of analog or digital. For example, aerial image of analog in the form of a film with a chemical process to get imagery, satellite imagery was obtained from sensors and electronic diporses digitally.  Satellite imagery is printed or hardcopy form may also be referred to as image/analog data.

Remote Sensing Data are not merely as an image, but the image data is stored in a regular grid format commonly referred to as raster data that consists of a line (row) and column (column). One of the smallest element (Figure 7) is named as a pixel (picture element). For each pixel has information coordinates (row and column) and spectral values are converted in the form of numbers, commonly referred to as DN (Digital Number).

1 Pixel

Each pixel represents the area of the surface of the Earth with the intensity and location of addresses in the form of 2-dimensional. Intensity values describing the size of the physical quantity which is the reflection of solar radiation emission or from an object with a specific wavelength that is received by the sensor. As mentioned earlier, the intensity of the pixel values are stored as digital (DN (Digital Number)). DN is stored in bits by a specified amount.

Figure 7.   Satellite imagery Data with spectral value assets

Remote sensing data quality on the main system characteristics are determined by the sensor platform.

Image: Landsat satellite image Data with spectral TM5 owns.

Characteristics of the system are usually indicated on sensor platforms:

1. Spectral radiometric resolution or

This resolution is based on each part of the electromagnetic spectrum that is measured and the difference in energy is observed. As an example: Landsat 7 ETM + has 9 channels/band, band 5 and SPOT5 using IKONOS II using 5 band.

2. Spatial Resolution

Spatial resolution is based on the smallest unit a measured object, indicating a minimum size of objects. For example the size of the per pixel to 5 m x 5 m Panchromatic SPOT5 and 2.5 m x 2.5; Multispektral 10 m x 10 m and Landsat 7 ETM Panchromatic + 15 m x 15 m; 30 m x 30 m Multispektral Thermal A and B 60 m x60m; as well as Panchromatic IKONOS II 1 m x 1 m, 4 m x 4 m Multispektral.

Image: comparison of spatial resolution satellite images Landsat MSS, Landsat 5 m 30 m 20 m TM5, SPOT4 and SPOT4 Pan 10 m. Landsat satellite image Data with spectral TM5 owns.

  3. Temporal Resolution (Repetition Of The Recording)

Temporal resolution (Revisit time) is the time loop recording data retrieval or on positions of the same object. Landsat 7 ETM + data retrieval or recording done in the position of an object on the same day, IKONOS setiap16 II for 4 days to an upright position and each day can do the recording for its ability to perekeman in obliq position (sideways).

More about → Satellite Remote Sensing Image