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3.0   MyEarth Search and Retrieval Tool

Close up views of the MyEarth v1.0 interface are shown in Figures 2 thru 12. Figure 2 shows the Search box on the Google Earth main window. MyEarth can be launched for operations at the same time as Google Earth by double clicking on the MyEarth icon, either from the Applications folder, or from the Dock. When MyEarth is launched, the browser is simultaneously launched with the Google Earth interface, and the initial Search form is viewable in the browser. From the browser window, simply select the Search menu item to begin using MyEarth. When the required search criteria have been entered via the Search form, the Save button may be pressed, to save out the Region-of-Interest (ROI). Alternatively, use the Search box directly in Google Earth to locate and launch the Search form. If the Search box itself is not visible on the Google Earth main interface, move the cursor to the Places pane to the left, and double click the Search link. My Earth interprets all these actions as being equivalent, with the result being a Search browser window, to enable search criteria to be entered, and saved.

Figure 2 – The MyEarth v1.0 Interface on Google Earth in the Mac OS X environment. With the white MyEarth form selected, double click the blue link marked “Minimum Bounding Rectangle” and manipulate the ROI directly in the Google Earth VG environment.

For a more direct method of manipulating the ROI, click on the blue link, marked Minimum Bounding Rectangle in the white search box, and choose Edit, and Get Info from the Google Earth main menu. Move the cursor over the red corner points, which mark out the yellow area, representing the ROI. These will become green handles, and may be modified. When done, save out the resultant ROI from the Save As menu item.

3.1   Region of Interest (ROI)

The Region of Interest marks out the overall area within which the data sets are to be found. The ROI may be specified via direct manipulation of the default minimum bounding rectangle, via the Google Earth main window, or by means of the MyEarth Search, or Advanced Search menus, which allow textual information to be entered via a browser form. The following information provides a definition of the ROI:

Northern Latitude

Northern most Latitude of ROI on VG Surface {maxLat};

Decimal degrees

Western Longitude

Western most Longitude of ROI on VG Surface {minLon};

Decimal degrees

Southern Latitude

Southern most Latitude of ROI on VG Surface when {minLat};

Decimal degrees

Eastern Longitude

Eastern most Longitude of ROI on VG Surface {maxLon};

Decimal degrees

Z

Elevation of ROI on VG Surface (only adjustable via the direct manipulation method)

meters mls

3.2   Temporal Range

The temporal range further refines the search criteria to reduce the results sets to those which are tagged with times/dates within a specified time range. This may be defined by means of the MyEarth Advanced Search menu only, which allow textual information to be entered via a browser form. The following information provides a definition of the Temporal Range:

Range Beginning Date

Start Date of the Temporal Range

Date

Range Beginning Time

Start Time of the Temporal Range

Time

Range Ending Date

Ending Date of the Temporal Range

Date

Range Ending Time

Ending Time of the Temporal Range

Time

3.3   Additional Attributes

The additional attributes are data or information which is tagged to the granule, which is specific to that data set. Day/Night Flag may be defined by means of the MyEarth Advanced Search menu only. Short Name may also be defined by means of the MyEarth Advanced Search menu only. The following information provides a definition of the Additional Attributes:

Day/Night Flag

Attribute set at the time the data set was captured. May be set to Day, Night or Both; users can opt not to select this attribute.

Selection Box

Short Name

Attribute used to describe the data set; Short Name given by the data provider.

Text field

3.4   Region of Interest (ROI) Option

The Region of Interest Option defines what the shape of the ROI will be. The ROI may be specified as the default minimum bounding rectangle (MBR), as a polygon, or as a point or a linestring by means of the MyEarth Preferences menu, which allow user selection to be made via a browser form. The following information provides a definition of the ROI Option:

Minimum Bounding Rectangle

A bounding box defining the ROI;

Selection Box

Polygon

A polygon defining the ROI;

Selection Box

Point

A point defining the ROI;

Selection Box

Linestring

A linestring defining the ROI;

Selection Box

3.5   VG Functions and Menus

Functions and Menus on the MyEarth Search and Retrieval Tool behave as follows:

Select

Welcome Screen following launch; not available once search has been selected.

Menu

Search

The basic MyEarth Interface to define and save the ROI, in terms of it minimum bounding rectangle (MBR).

Menu

Advanced Search

The advanced MyEarth Interface to define and save the ROI, both in terms of its MBR, temporal range and additional attributes.

Menu

Preferences

The MyEarth Interface to define ROI preferences, a single choice of either {MBR, Polygon, LineString, Point};

Menu

User Manual

A simple on-line user manual, whicih explains the main functions and menus of the MyEarth Search and Retrieval Tool;

Menu

Help

A self explanatory help file, which explains what the MyEarth Interface can do, and what it can be made to do;

Menu

Open Search

This works just like opening a form in a browser, only you are opening a search form to go searching data sets around the world instead! Fun! Just select your region, provided it is on the Earth, and go search it! The choice for entering search parameters are described in the Search Menu section! A snapshot of this menu is shown in Figure 3.

Save Search Criteria

Just set up the north, east, south and west ordinates of your bounding box, any way you want and save the search. That search will remain as the defined search criteria unless you save out the parameters again. Search regions of interest are saved in the "kml" folder as the file: MinimumBoundingRectangle.kml.

Figure 3 – The MyEarth v1.0 Search Menu on Google Earth™ in the Mac OS X environment. With the four text fields, the user identifies the spatial extent {maxLat, minLon, minLat, maxLon} of the ROI on the Earth’s surface. The ROI is saved to the file: MinimumBoundingRectangle.kml.

Open Advanced Search

This works in a similar way to when you are opening a search form but provides several additional search features, such as a time range, and selection of attributes pertinent to your data granules. Just select your region, as before, and this time, enter the range beginning date, range beginning time, and the range ending date and range ending time, then go search it! A snapshot of this menu is shown in Figure 4.

Save Advanced Search Criteria

Just with the Search menu, the search regions of interest are saved in the "kml" folder as the file: MinimumBoundingRectangle.kml. In addition, the time range is saved, and the additional attributes are saved as the file Attributes.kml.

Figure 4 – The MyEarth v1.0 Advanced Search Menu on Google Earth™ in the Mac OS X environment. With the four text fields, the user’s identifies the spatial extent {maxLat, minLon, minLat, maxLon} of the ROI on the Earth’s surface. The ROI is saved to the file: MinimumBoundingRectangle.kml. The selected additional attributes are saved to the file: Attributes.kml.

Enter Preferences

This option allows you to select the method of specifying the region-of-interest (ROI). You need to choose what shape is the most suitable comparison to go searching data sets against! This is where it gets interesting! You are then ready to venture out on to the Earth, via the Google Earth main window, and select which one of the predefined searches is closest to the search you would like to perform.

Save Preferences

Saving your preferences is an essential part of defining the type of search you require. These preferences are referenced each time a search is executed. Preferences are saved in the "kml" folder as the file: Preferences.kml.

Figure 5 – The MyEarth v1.0 Preferences Menu on Google Earth™ in the Mac OS X environment. User selects an ROI Option, a Query Type and a Search Type from the pull-down selection lists. The selected options are saved to the file: Preferences.kml.

Minimum Bounding Rectangle and the 3-D Map

Defining your Minimum Bounding Rectangle (MBR) is an essential part of defining the search criteria you require. The ROI provides the spatial search engine (SSE) with a reference shape, which is compared to the spatial information stored in the database for each data set in turn, each time a search is executed. If the search quest is MBRContains, then the SSE determines whether the spatial extent of the data set is contained within the MBR defined as the ROI. If returns TRUE if the data set located within the ROI and it appears in the results set, under the places pane, visible from the Google Earth main window.

Figure 6 – The MyEarth Interface which allows users to define the Region-of-Interest (ROI) is launched from the Places Pane, to the left of the Google Earth main windows, as shown in this figure.

Handle Controls

Handle Controls are hidden to begin with. If the ROI is shown in the Google Earth main window, and it selected in the Places pane, then select “Edit” from the main menu, the “Get Info”, and hover the cursor over the red corner points. As the cursor encounters a corner point, it changes to a “handle” symbol and the points change to green. They may be moved relative to the Earth, and the resultant ROI may be saved using the “Save As” menu option. It is important to replace the existing ROI, by choosing the same filename and directory as used by the previous ROI, e.g for the Minimum Bounding Rectangle, choose filename: MinimumBoundingRectangle.kml, which is saved to the directory /usr/local/apache2/htdocs/kml, as type: {kml}. Use Command-Shift-G to gain access to this directory, which is not normally accessible to users. When prompted, enter “/usr/local/apache2/htdocs/kml” and click the “GoTo” button. Select type: {kml}, and then “Save”.

Figure 7 – MyEarth Search and Retrieval Tool with Query Results visible. My Places pane shows a new link under Temporary Places (middle left) and when selected and opened, MBRContains Query Results reveals new item ground overlay image of the MODIS data set browse image that is located within the ROI. Image details are returned for this browse image in the form of a ShortName and the filename, where the browse image stored in the Archive.

Polygon and the 3-D Map

Editing the Polygon ROI on the 3-D Map is done in a similar way to the editing of the Minimum Bounding Rectangle. From the main menu, choose Edit, then Get Info, with the Polygon link selected. Handle Controls are will appear in the main Google Earth window. Hover the cursor over the red corner points, which become green, marking their availability for editing. The main difference between Polygons and Minimum Bounding Rectangles is they possess 4 or more points to define the ROI. Minimum Bounding Rectangles may only contain 4 points, and they are defined by the northern, western, eastern and southern-most extent. Polygons, however, are defined by exact {lat, lon} coordinates, and additional points may be added during editing on the 3-D Map. No additional points may be added during the editing of Minimum Bounding Rectangles.

Figure 8 – MyEarth Search and Retrieval Tool with Polygon editing on the 3-D map in progress. Note the lower link of the Polygon is selected in the Places pane. The editing of the Polygon ROI directly within the Virtual Globe (VG) Visualization Environment, provides an efficient means to define the ROI, and also provides a reference on the 3-D map, in preparation for executing the spatial query.

Saving the Polygon ROI on the 3-D Map, once the editing is done, is similar to the method used for the Minimum Bounding Rectangle. The resultant ROI may be saved using the “Save As” menu option, from Google Earth. Take care to retain the kml file type and replace the existing Polygon.kml file.

Figure 9 – MyEarth Search and Retrieval Tool showing the method of Saving the Polygon on the 3-D map. Choose Edit, then Save As. The resultant Polygon ROI is saved to the file: Polygon.kml

Prior to performing a Polygon search, navigate to the Preferences menu, by clicking the Enter Search Preferences link on the white MyEarth form. Select “Polygon” from the ROI Type pull-down menu, then select “Contains” form the Query Type pull-down menu, then “Search” from the Search Type pull-down menu. Now MyEarth is ready for spatial query execution. This preferences combination will launch a PolygonContains query. Note this feature is new in MyEarth v1.0, and searches ESRI Shapefiles only. To execute the spatial query click the “Execute Spatial Query” link from the white MyEarth form.

Query results are returned to directly into the Virtual Globe (VG) visualization environment, and the data sets are listed within network links within the Places Pane, and displayed on the Google Earth main window. Figure 10 shows the query results from the PolygonContains query, for the spatial region of interest defined earlier.

Figure 10 – MyEarth Search and Retrieval Tool showing the spatial query results and the Polygon ROI which represents the spatial search region. ESRI shapefiles are shown as shp files within Network Links, and their features are selectable by expanding the link. Note the Info Placemark, marking the center points of these shp files.

With ESRI Shapefiles, the browse image is preferably saved to a Keyhole Markup Language (KML) file for direct display within the Google Earth visualization environment. The feature details are all available for selection, and in the example shown in Figure 11, a single schools district, representing one county can be selected and the features highlighted

Figure 11 – MyEarth Search and Retrieval Tool showing the feature details of an ESRI shapefile, returned in the spatial query results set, from a Polygon Contains query. IN this case the Scott County Public Schools region is selected from the Virginia Schools District. These are available as part of the U.S. Census 2000 data sets.

Often it is desirable to superimpose many shapefile features in one view. This is possible in Google Earth, using the MyEarth Search and Retrieval Tool to selectively search and display query results directly in the Virtual Globe (VG) Visualization Environment. In the example shown in Figure 12, a set of ESRI shapefiles is displayed following a spatial search encompassing the Mexico region. The data sets are indicated to be of data type: shp, and the detailed features available include: roads, routes, lakes, rivers, cities and states, and all are individually selectable.

Figure 12 – MyEarth Search and Retrieval Tool showing the feature details of an ESRI shapefile for the Mexico region, returned in the spatial query results set. The Polygon ROI is defined for the entire region, whereby a PolygonContains query returns a number of shp files. Each file contains separately selectable features: cities, roads, rivers, lakes, routes, and states.

LineStrings and Points on the 3-D Map

LineString and Points are available to define the ROI in MyEarth v1.0. Editing the LineString or Points as ROI on the 3-D Map is done in a similar way to the editing of the Minimum Bounding Rectangle. From the main menu, choose Edit, then Get Info, with the LineString or Point link selected. Handle Controls are will appear in the main Google Earth window. There will be two points only for a LineString, and the Point will appear as an editable Placemark on the 3D Map. The resultant ROI may be saved using the “Save As” menu option, from Google Earth. Take care to retain the kml file type and replace the existing LineString.kml or Point.kml file, depending on the ROI type you are editing. To select the ROI type for spatial search, go to Enter Preferences form, and select either LineString or Point from the pull-down menu, and Save the preferences in the file: Preferences.kml, in the same way as for the MBR or Polygon ROI type.
MyEarth Logo Section 1
Introduction		   Section 2
Getting Started		   Section 3
MyEarth Search and Retrieval Tool		   Section 4
Ingesting Data Sets		   Section 5
Using MyEarthAdmin