Notes from Edinburgh workshop, 20th November 2006

Web server is Apache, dynamic content served by Tomcat. Just use Tomcat on its own for development.

Rob Pedley uses Struts - helpful for session persistence and handling forms (repopulates forms).

Spatial location of data is really an attribute of the geomag data (doesn't change). Are there any standards for general timeseries data?

Software engineering practices: Subversion, Maven, JUnit

Project tracking: Trac - does bug reporting, progress checking: a lightweight web-based project management solution. Integrates with Subversion.

System Architecture

GeoMagServlet

GetCapabilities

Returns list of observatories with their unique codes (NAME), lat, long, elevation, human-readable name (TITLE) and possibly address, contact details

http://myserver/GeoMag?REQUEST=GetCapabilities&FORMAT=XML&LEVEL_OF_DETAIL=??? (maybe HTML also)

(LEVEL_OF_DETAIL: need to define possible levels of detail)

Capabilities document for an OGC Web Map Service: http://lovejoy.nerc-essc.ac.uk:8080/ncWMS/WMS.py?SERVICE=WMS&REQUEST=GetCapabilities

Schema document for the WMS Capabilities doc: http://schemas.opengis.net/wms/1.3.0/capabilities_1_3_0.xsd

DescribeData

Returns metadata for an observatory's data holdings: start time, end time, measurements per day, available publication states

http://myserver/GeoMag?REQUEST=DescribeData&OBSERVATORY_CODE=esk&start_time=???&end_time=???&FORMAT=XML

Parameter	Mandatory/Optional?	Default	Notes
REQUEST	M		always DescribeData
OBSERVATORY_CODE	M	none
START_TIME	O	data start time	ISO 8601 format
END_TIME	O	data end time	ISO 8601 format
INCLUDE_DAY_COUNT	O	false
FORMAT	O	XML

GetData

Parameter	Mandatory/Optional?	Default	Notes
REQUEST	M		always GetData
OBSERVATORY_CODE	M	none
START_TIME	O	data start time	ISO 8601 format
END_TIME	O	data end time	ISO 8601 format
FORMAT	O	XML	XML, PNG, EXCEL, etc
PUBLICATION_STATE	O	ANY	ADJUSTED_OR_REPORTED,DEFINITIVE,PROVISIONAL,ADJUSTED,REPORTED,ANY
INCLUDE_HEADER	O	true	Can set false to get only data

Returns the four components of the mag vector for each measurement time, plus optional header information.

Charting

JFreeChart: http://www.jfree.org/jfreechart/

Example of combined plots: http://www.java2s.com/Code/Java/Chart/JFreeChartCombinedXYPlotDemo1.htm

OGC Standards

http://www.opengeospatial.org

Sensor Web Enablement Working Group: http://www.opengeospatial.org/projects/groups/sensorweb

-- JonBlower - 20 Nov 2006