Metadata Browser Help

Purpose
The VIEWS Metadata browser provides geographical browsing capabilities for the monitoring programs in the VIEWS database.  The Metadata browser displays monitoring site locations using a fully functional Web based Geographical Information System (GIS).  The GIS capabilities allow simultaneous display of site locations and geographical information, such as county boundaries, cities, U.S. Parks, etc.  Most geographical layers can be used to select associated monitoring sites.

Use
When the Metadata browser is first loaded on your browser the default view is a map of the Continental U.S. showing locations of IMPROVE aerosol monitoring sites and states colored by their representative RPO.  Click on one or more monitoring programs in the 'Programs' list box to the right of the map to display site locations for the selected program(s).  Tabular metadata for the selected program(s) is shown below the map.  More advanced features, such as updating geographical layers, controlling the map view, and obtaining detailed monitoring site and layer metadata is provided below.

GIS Layers:

Selecting Layers
The GIS Layers pane has check boxes that allow the user to turn on and off geographical layers in the map view.  Check any of the layers then press the 'Update Map' button to update the current map view with the selected layers.  When the Metadata browser is first loaded by your browser the RPO layer is displayed by default.  The RPO layer shows states color coded by their representative RPO.  Note that un-checking any layer that displays a typical map view (such as RPO or Cont. U.S.) will render a map view without a base map. 

The layers are ordered from top to bottom in the GIS layers pane so that upper most layers are displayed on top of lower layers.  For example, if both RPO and Cont. U.S. layers are checked, only the RPO layer will be visible because it is on top of the Cont. U.S. layer.

Available Layers
Roads show major interstates in the Continental U.S.

Rivers show major rivers in the Continental U.S.

Cities show point locations of cities in the Continental U.S. with populations over 25,000.  The size of the city icon is related to the city population.

Urban Areas shows major U.S. urban areas.

US Parks show NPS park lands in the U.S. The parks are divided into Class I and Class II Areas.

Class I Areas shows all the 156 Class I Areas in the U.S.  Clicking on any of these area will provide metadata about the IMPROVE monitoring site that represents the selected Class I area.

Counties show U.S. county regions including counties in Alaska and Hawaii.  Clicking within the boundaries of any county will display metadata about monitoring sites in that county.

RPO shows states regions in the Continental U.S. The states are color coded by their representative RPO.  This is a low-resolution layer.

Cont. U.S. shows states in the Continental U.S.  This is a high-resolution layer.  Clicking within the boundaries of any state will display metadata about monitoring sites in that state.

Alaska, Hawaii, Caribbean layers are high-resolution layers of the respective states or regions.  Clicking within the boundaries of any of these regions will display metadata about monitoring sites in the selected region.

Canada, Mexico, and N. America layers are low-resolution layers of the respective states or regions.  Clicking within the boundaries of any of these regions will display metadata about monitoring sites in the selected region.

Note, some some layers are available as low-resolution layers and some as high-resolution layers.  Low-resolution layers have less geographical detail and are sufficient for large scale views.  If you want to zoom in and see more geographical detail, choose a high-resolution layer.  For example, the RPO layer has sufficient resolution to display a large scale view of the U.S., however if one zooms in on a specific area, such as the San Francisco Bay Area, the Cont. U.S. layer will provide more geographical detail.  The advantage of low-resolution layers is they will allow the Metadata browser application to run faster.  Also, keeping the selected layers to the minimum necessary to provide desired information will help the Metadata Browser run faster.

Map Controls:

General
At the top of the map is the map toolbar.  The map toolbar has various icons from which the user can control the map view, such as zooming in and out.  On the bottom of the map are three panes that describe the current map mode and view.  The bottom left pane shows the current map mode.  The bottom center pane shows the central latitude and longitude of the current map view.  The bottom right pane shows the current map scale in normalized units.  For example, when the page first loads with a view of the Continental U.S. the scale is 1:36 million, or one centimeter on the map equals 360 km in actual distance.

Toolbar
The map toolbar is on top of the map.  Mouse over the toolbar icons to see a 'tool-tip' describing the respective function.  The five right hand icons control the map mode.  If selected, the Mode icons are highlighted and the selected mode is shown at the lower left of the map.  The five left most icons zoom to a predefined map extent.

Map Mode Toolbar icons
Center will make the point on the map where the use clicks with the mouse the new center of the map.

Zoom In will zoom the map to 2X the previous scale with the new center of the map the  point of the mouse click.

Zoom Out will zoom the map to 1/2X the previous scale with the new center of the map the the point of the mouse click.

Zoom Box will draw a rectangle on the map if the user clicks and drags the mouse across a region of the map.  The map will zoom in on the region of the box.

Zoom In will zoom the map to 2X the previous scale on the point of the mouse click.

Info mode is activated by clicking the i  toolbar icon.  In 'Info' mode clicking on the map will select the closest available map feature.  If monitoring sites lie within a selected feature, such as a state or county boundary, metadata for the GIS layer and sites associated with the layer's selected region are displayed.  Clicking directly on a point, such as a city or monitoring site, will select that point.  Selected map features are highlighted in red.

Map Extent Toolbar icons
NA zooms to North America and selects the N. America GIS layer.

US zooms to the Continental U.S. and selects the Cont. U.S. GIS layer.

AK zooms to Alaska and selects the Alaska GIS layer.

HI zooms to the Hawaiian Islands and selects the Hawaii GIS layer.

CAR zooms to a region of the Caribbean centered on the Virgin Islands and selects the Caribbean GIS layer.

Map Labels:

Legend:

Expand the legend pane to view the map legend.  The legend applies only to specific GIS layers.

Tabular metadata:

Tables below the map show program information for selected program(s).  In 'info' mode layer information for the selected layer region is displayed.  If monitoring sites are associated with the layer region, site metadata is also displayed.  For example, to display metadata for all IMPROVE sites in Colorado, use a GIS layer that displays state areas and in 'info' mode mouse click anywhere within Colorado.  To view only the monitoring sites in Larimer County, Colorado, select the county layer then mouse click inside the county boundaries.

Planned Modifications:

Planned modifications to the metadata browser include:

• Make individual site metadata appear when the user's mouse is placed over the site.
• Adding the ability to select multiple sites using a radius tool.
• Adding new GIS layers and creating new site-layer relationships.
• Incorporating the GIS tool as a selection tool for charting applications.

Bugs:

The metadata browser incorporates advanced web-based features that may not be compatible with all browsers types, some older browser versions, and/or specific browser proxy settings.  We are currently aware of problems some users are experiencing and are working to resolve these issues.  If you experience problems with this application, we would appreciate your feedback.