erdSHcdev8day

Dataset Title:	Chlorophyll-a Deviation, Orbview-2 SeaWiFS, West US (8 Day Composite)
Dataset ID:	erdSHcdev8day
Institution:	NOAA CoastWatch, West Coast Node
Information:	Summary \| Variables \| Background \| Data Access Form \| Make A Graph

This web page is using OpenLayers to display maps which are created on-the-fly by ERDDAP's Web Map Server (WMS) version 1.3.0. The controls on the left of the map are for navigation. The control on the right manages the layers. You can select different values for the data variable's dimension(s):
time:
altitude:	0.0

What is WMS?

ERDDAP's Web Map Service (WMS) lets you request an image with data plotted on a map.
WMS is an Open Geospatial Consortium (OGC) and ISO (19128) standard for "the creation
and display of registered and superimposed map-like views of information that come
simultaneously from multiple remote and heterogeneous sources."
See the list of datasets available via WMS at this ERDDAP installation.

Three Ways to Make Maps with WMS

In theory, anyone can download, install, and use WMS client software.
Some clients are: ArcGIS, Refractions PHP WMS Client, and uDig.
To make a client work, you would install the software on your computer.
Then, you would enter the URL of the WMS service into the client.
For example, in ArcGIS (not yet fully working because it doesn't handle time!), use
"Arc Catalog : Add Service : Arc Catalog Servers Folder : GIS Servers : Add WMS Server".
In ERDDAP, this dataset has its own WMS service, which is located at
http://coastwatch.pfeg.noaa.gov/erddap/wms/erdSHcdev8day/request?
(Some WMS client programs don't want the ? at the end of that URL.)
See the list of datasets available via WMS at this ERDDAP installation.
In practice, we haven't found any WMS clients that properly handle dimensions
other than longitude and latitude (e.g., time), a feature which is specified by the WMS
specification and which is utilized by most datasets in ERDDAP's WMS servers.
You may find that using Make A Graph and selecting the .kml file type (an OGC standard)
to load images into Google Earth provides a good (non-WMS) map client.
See the list of datasets with Make A Graph at this ERDDAP installation.
Web page authors can embed a WMS client in a web page.
For the map above, ERDDAP is using OpenLayers, which is a very versatile WMS client.
OpenLayers doesn't automatically deal with dimensions other than longitude and latitude (e.g., time),
so you will have to write JavaScript (or other scripting code) to do that.
(Adventurous JavaScript programmers can look at the Souce Code for this web page.)
A person with a browser or a computer program can generate special GetMap URLs and view/use the resulting image file.
Opaque example: http://coastwatch.pfeg.noaa.gov/erddap/wms/erdBAssta5day/request?service=WMS&version=1.3.0&request=GetMap&bbox=0,-75,360,75&crs=EPSG:4326&width=360&height=150&bgcolor=0x808080&layers=Land,erdBAssta5day:sst,Coastlines,Nations&styles=&format=image/png
Transparent example: http://coastwatch.pfeg.noaa.gov/erddap/wms/erdBAssta5day/request?service=WMS&version=1.3.0&request=GetMap&bbox=0,-75,360,75&crs=EPSG:4326&width=360&height=150&bgcolor=0x808080&layers=erdBAssta5day:sst&styles=&format=image/png&transparent=TRUE
See the list of datasets available via WMS at this ERDDAP installation.
For more information, see ERDDAP's WMS Documentation .
In practice, it is probably easier and more versatile to use this dataset's Make A Graph form
than to use WMS for this purpose.
See the list of datasets with Make A Graph at this ERDDAP installation.

ERDDAP Version 1.22

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