Coordinate
Acquisition Tool (CAT)
Integrated into SeismiQuery
The Institute for the Application of Geospatial Technology at Cayuga
Community College (IAGT – www.iagt.org)
is pleased to announce the release of its Coordinate Acquisition Tool
(CAT) for Google Maps. CAT has been integrated into
the DMC SeismiQuery software application (http://www.iris.edu/SeismiQuery/events.htm)
that provides access to all IRIS seismic data. CAT provides
an easy way to fetch geographic coordinates from a simple map interface.
The tool is launched in a popup window from a parent html application,
in this case by clicking on the globe image in the ‘latitude and
longitude’ section of SeismiQuery (Fig. 1). The
coordinates are obtained by either getting the current map extent, or
by dragging a rectangle within the extent. They are then returned
to the parent page, in this case to populate text boxes corresponding
to the respective bounding geographic extents to be used as a filter
for further SeismiQuery interaction.
Figure 1: Shows rectangle-drag for extent coordinates
Some technical aspects of the CAT :
- Written in HTML/JavaScript, and designed to be launched in a popup
window.
- Uses the drag_zoom.js JavaScript library, which has been adopted
by Google from the original “GZoom” library. Also uses
Walter Zorn’s vector JavaScript library. These libraries are
responsible for the rectangle effects.
- Uses a freely available WMS JavaScript library, created primarily
for use with Google Maps. This library allows one to overlay your own
WMS data over Google Maps data (Fig. 2), or to simply create your own
WMS map (combining map layers from multiple servers).
- A CustomButtonControl class has been included which is used for the
Map Extent button, and which could be leveraged to make other tool
buttons (with on/off states).
Figure 2: Custom WMS layer of IRIS Stations overlaid on
Google Satellite Imagery
For more information regarding the CAT, contact Dan Deneau
at IAGT (ddeneau@iagt.org).
IAGT has been providing geospatial tools and technical support to IRIS
through funding from NASA under the EarthScope program, and has been
a partner since the very beginning of the NSF funded program. For
instance, IAGT has been providing routine updates of Google Earth kmz
files that show the current state of the Transportable Array and provide
links to station information (http://arcserver1.iagt.org/TacoKMZ/TacoKMZ.aspx linked
from http://www.iris.edu/USArray/researchers/ta.html). Another
example is the ‘Suggest a Site’ application (http://www.iris.edu/USArray/landowners/suggest_a_site.html)
that IRIS is using to engage the public in the Transportable Array siting
process.
IAGT also provides geospatial support to UNAVCO under the Plate Boundary
Observatory (PBO) component of EarthScope, and has developed extensive
geospatial analysis and visualization tools under that component for
instrument site selection and information management. Examples include:
a web-based application for determining line-of-sight between distributed
communications infrastructure in remote areas (http://www.iagt.org/earthscope/es-viewshed.asp);
the PBO Network Progress and State of Health interactive mapping components
(http://pbowms.unavco.org/shared/scripts/mapping/map.shtml?map=progress);
and the creation of Network Progress Google Earth kmz station files (http://pboweb.unavco.org/local/downloads/gearth/pbonetwork.kmz).
For general information regarding IAGT’s geospatial technical
development services, contact Fred Pieper (fpieper@iagt.org).
Go to: CAT using
SeismiQuery
Submitted by Dan Deneau, Fred Pieper, and Dana Piwinski - IAGT |
