ECHO has been replaced by the Common Metadata Repository (CMR), a high-performance, high-quality, continuously evolving metadata system that catalogs all data and service metadata records for the EOSDIS system and will be the authoritative management system for all EOSDIS metadata.

The information contained within this ECHO wiki is now archived for historical reference. Please navigate to the CMR wiki pages, or to the CMR Overview page on Earthdata.

Guide Navigation

Acronyms used in ECHO

Acronyms used in this document are contained in this appendix.

ACL	Access Control List
API	Application Programming Interface
AQL	Alternative Query Language
ASF DAAC	Alaska Satellite Facility DAAC
ASTER	Advanced Spaceborne Thermal Emission and Reflection Radiometer
BMGT	Bulk Metadata Generation Tool
COTS	Commercial Off The Shelf
DAAC	Distributed Active Archive Center
DB	DataBase
DTD	Document Type Definition
ECHO	EOS Clearinghouse
ECS	EOSDIS Core System
EDC	EROS Data Center
EDG	EOS Data Gateway
EJB	Enterprise JAVA Beans
EMD	EOSDIS Maintenance and Development
EOS	Earth Observing System
EOSDIS	EOS Data and Information System
EROS	Earth Resources Observation Systems
ESDIS	Earth Science Data and Information System
ESIP	Earth Science Information Partner
ETC	ECHO Technical Committee
FTP	File Transfer Protocol
GCMD	Global Change Master Directory
GES DAAC	GSFC Earth Sciences DAAC
GHRC	Global Hydrology Resource Center
GIS	Geographic Information System
GML	Geography Markup Language
GMT	Greenwich Mean Time
GSFC	Goddard Space Flight Center
GUI	Graphical User Interface
GUID	Globally Unique Identifier
IIMS	Independent Information Management Subsystem
J2EE	Java 2 Enterprise Edition
LAADS	Level 1 and Atmosphere Archive and Distribution System
LP DAAC	Land Processes DAAC
MISR	Multiangle Imaging SpectroRadiometer
MODIS	Moderate Resolution Imaging Spectroradiometer
NASA	National Aeronautics and Space Administration
NSIDC DAAC	National Snow and Ice Data Center DAAC
ODL	Object Description Language
OGC	OpenGIS Consortium
ORNL DAAC	Oak Ridge National Laboratory DAAC
PGE	Product Generation Executives
PO.DAAC	Physical Oceanography DAAC
PSA	Product Specific Attribute
PUMP	Provider User Management Program
QA	Quality Assurance
SEDAC	Socioeconomic Data and Applications Center
SOAP	Simple Object Access Protocol
SSC	Stennis Space Center
SSL	Secure Sockets Layer
UDDI	Universal Description, Discovery, and Integration
UI	User Interface
UR	Universal Reference
URI	Uniform Resource Identifier
URL	Uniform Resource Locator
UTC	Universal Time, Coordinated (also called GMT/UTC)
WIST	Warehouse Inventory Search Tool
WGS	World Geodetic System
WRS	Worldwide Reference System
WSDL	Web Services Description Language
XML	eXtensible Markup Language
XSLT	eXtensible Style Language Transformation

Sample queries

Sample Granule Query Using Various Granule Conditions (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE query PUBLIC "-//ECHO CatalogService (v{*}10{*})//EN" "http://api.echo.nasa.gov/echo/dtd/IIMSAQLQueryLanguage.dtd">
Search for granules from the L70R or L70RWRS or GLCF_GRANULE_METADATA datasets that have Browse data and were categorized as day granules. -->
<query>
	<for value="granules"/> 
		<dataCenterId>
			<list> 
				<value>ORNL_DAAC</value>
			</list>
		</dataCenterId>
	<where>
		<granuleCondition>
			<browseOnly/>
		</granuleCondition>
		<granuleCondition>
			<cloudCover>
				<range lower="10" upper="20"/> 
			</cloudCover>
		</granuleCondition>
		<granuleCondition>
			<dataSetId>
				<list>
					<value>'L70R'</value>
					<value>'L70RWRS'</value> 
					<value>'GLCF_GRANULE_METADATA'</value>
				</list>
			</dataSetId>
		</granuleCondition>
		<granuleCondition> 
			<dayNightFlag value="DAY"/> 
		/granuleCondition>
	</where>
</query>

Sample Granule Query Using Spatial and Temporal Bounds (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE query PUBLIC "-//ECHO CatalogService (v{*}10{*})//EN" "http://api.echo.nasa.gov/echo/dtd/IIMSAQLQueryLanguage.dtd">
Search for granules the specified spatial region, and periodic temporal extent
--> 
<query>
	<for value="granules"/> 
	<dataCenterId>
		<list> 
			<value>ORNL_DAAC</value>
		</list>
	</dataCenterId>
	<where>
		<granuleCondition>
			<spatial operator="RELATE"> 
				<IIMSPolygon>
					<IIMSLRing>
						<IIMSPoint lon="-120" lat="-30" /> 
						<IIMSPoint lon="-100" lat="-60" /> 
						<IIMSPoint lon="-5" lat="-90" /> 
						<IIMSPoint lon="5" lat="85" /> 
						<IIMSPoint lon="-120" lat="30" /> 
						<IIMSPoint lon="-120" lat="-30" />
					</IIMSLRing>
					<IIMSLRing>
						<IIMSPoint lon="80" lat="20" /> 
						<IIMSPoint lon="80" lat="60" /> 
						<IIMSPoint lon="20" lat="60" /> 
						<IIMSPoint lon="20" lat="20" /> 
						<IIMSPoint lon="80" lat="20" />
					</IIMSLRing>
				</IIMSPolygon>
			</spatial>
		</granuleCondition>
		<granuleCondition>
			<temporal>
				<startDate>
					<Date YYYY="1989" MM="01" DD="01"/>
				</startDate> 
				<stopDate>
					<Date YYYY="1998" MM="12" DD="31"/>
				</stopDate> 
				<startDay value="1"/>
				<endDay value="300"/> 
			</temporal>
		</granuleCondition>
	</where>
</query>

Sample Granule Query Using Sensor Name (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<query>
	<for value="granules"/> 
	<dataCenterId>
		<list>
			<value>ORNL_DAAC</value>
		</list> 
	</dataCenterId>
	<where>
		<granuleCondition>
			<sensorName>
				<list>
					<value>'SWIR'</value>
					<value>'TIR'</value>
				</list>
			</sensorName>
		</granuleCondition>
	</where>
</query>

Sample Granule Query Using Temporal Constraints (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE query PUBLIC "-//ECHO CatalogService (v{*}10{*})//EN" "http://api.echo.nasa.gov/echo/dtd/IIMSAQLQueryLanguage.dtd">
Search for granules with temporal range: periodic range between Jan 1, 1990 and Dec. 31 1998 from the 1st to the 300th day
of each year. -->
<query>
	<for value="granules"/> 
	<dataCenterId>
		<list> 
			<value>ORNL_DAAC</value>
		</list>
	</dataCenterId>
	<where>
		<granuleCondition>
			<temporal>
				<startDate>
					<Date YYYY="1990" MM="01" DD="01"/> 
				</startDate>
				<stopDate>
					<Date YYYY="1998" MM="12" DD="31"/>
				</stopDate> 
				<startDay value="1"/>
				<endDay value="300"/> 
			</temporal>
		</granuleCondition>
	</where>
</query>

Sample Granule Query Using Additional Provider Specific Attributes (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE query PUBLIC "-//ECHO CatalogService (v10)//EN" "http://api.echo.nasa.gov/echo/dtd/IIMSAQLQueryLanguage.dtd"> <query>
	<for value="granules"/>
	<dataCenterId> 
		<value>ORNL_DAAC</value>
	</dataCenterId>
	<where>
		<granuleCondition>
			<additionalAttributes>
				<additionalAttribute> 
					<additionalAttributeName>'COORDINATE_UNITS_NAME'</additionalAttributeName>
					<additionalAttributeValue>
						<value>'METERS'</value>
					</additionalAttributeValue>
				</additionalAttribute> 
			 </additionalAttributes>
		</granuleCondition>
	</where>
</query>

Sample Granule Query Using Additional Provider Specific Attributes with Complex Values (Inventory)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE query PUBLIC "-//ECHO CatalogService (v10)//EN" "http://api.echo.nasa.gov/echo/dtd/IIMSAQLQueryLanguage.dtd"> 
<query>
	<for value="granules"/> 
	<dataCenterId>
		<value>ORNL_DAAC</value> 
	</dataCenterId>
	<where>
		<granuleCondition>
			<additionalAttributes>
				<additionalAttribute>
					<additionalAttributeName>'SAMPLE_DATE'</ additionalAttributeName> 
					<additionalAttributeValue>
						<dateRange>
							<startDate>
								<Date YYYY="2000" MM="05" DD="12"/> 
							</startDate>
							<stopDate>
								<Date YYYY="2000" MM="10" DD="12"/> 
							</stopDate>
						</dateRange>
					</additionalAttributeValue>
				</additionalAttribute>
			</additionalAttributes>
		</granuleCondition>
	</where>
</query>

DTD Results

ECHO Collection Results DTD

The ECHO Collection Results DTD is located at the following link: ECHO Collection Results DTD

ECHO Granule Results DTD

The ECHO Granule Results DTD is located at the following link: ECHO Granule Results DTD

Best Practices for Queries

The following tips and other recommended practices will improve the efficiency of queries.

Best Practices for Faster Queries

Limiting the end user choices will lead the user down a logical path. This will promote efficiency by limiting the choice to those applicable to the user's needs.
Search for collections first and limit the collection search spatially or temporally and by data center. Limiting the collection will result in a narrower search and a smaller, more focused result set.
Queries are optimized to return as soon as the requested iterator size is found. Therefore, to do a check for the existence of data, use a small iterator size such as 1 rather than a HITS query.
The result type HITS requires the query to be executed and the entire result set identified and counted. Use this result type extremely sparingly.
Use the MetadataAttributes to return only the necessary attributes when presenting data. ECHO defaults to all attributes, which will take longer to return and display.
Request only what the user would see in the first few pages. For example, if the client only supports displaying 10 pages of 10 items, use an iterator size of 100. The client may want to pre-fetch the next page of results while the user is examining the first page.
The user of the value element will be more efficient than the use of the range element in general.

Efficient Spatial Queries

If you are querying a single Data Partner, name the Data Partner in the query.
If you are querying a single collection, include the name of the collection in the query.
Queries for smaller spatial regions return faster than queries for broader regions.
Queries for spatial regions with fewer points return faster results than queries with more point

Space shortcuts

Page tree

Acronyms used in ECHO

Sample queries

DTD Results

ECHO Collection Results DTD

ECHO Granule Results DTD

Best Practices for Queries

Best Practices for Faster Queries

Efficient Spatial Queries

Space shortcuts

Page tree

ECHO Client Partner User Guide Appendices

Acronyms used in ECHO

Sample queries

DTD Results

ECHO Collection Results DTD

ECHO Granule Results DTD

Best Practices for Queries

Best Practices for Faster Queries

Efficient Spatial Queries