The documents are returned sorted on relevance depending on order, proximity, frequency of terms.
Default search behavior
By default, all search terms are optional. It behaves like an OR logic. Objects that contain the more terms are rated higher in the results and will appear first in their type. For example, wiki forum will find:
- objects that include both terms
- objects that include the term wiki
- objects that include the term forum
Requiring terms
Add a plus sign ( + ) before a term to indicate that the term must appear in results. Example: +wiki forum will find objects containing at least wiki. Objects with both terms and many occurences of the terms will appear first.
Excluding terms
Add a minus sign ( - ) before a term to indicate that the term must not appear in the results. To reduce a term's value without completely excluding it, use a tilde. Example: -wiki forum will find objects that do not contain wiki but contain forum
Grouping terms
Use parenthesis ( ) to group terms into subexpressions. Example: +wiki +(forum blog) will find objects that contain wiki and forum or that contain wiki and blog in any order.
Finding phrases
Use double quotes ( " " ) around a phrase to find terms in the exact order, exactly as typed. Example: "Alex Bell" will not find Bell Alex or Alex G. Bell.
Using wildcards
Add an asterisk ( * ) after a term to find objects that include the root word. For example, run* will find:
- objects that include the term run
- objects that include the term runner
- objects that include the term running
Reducing a term's value
Add a tilde ( ~ ) before a term to reduce its value indicate to the ranking of the results. Objects that contain the term will appear lower than other objects (unlike the minus sign which will completely exclude a term). Example: +wiki ~forum will rate an object with only wiki higher that an object with wiki and forum.
Changing relevance value
Add a less than ( < ) or greater than ( > ) sign before a term to change the term's contribution to the overall relevance value assigned to a object. Example: +wiki +(>forum < blog) will find objects that contain wiki and forum or wiki and blog in any order. wiki forum will be rated higher.
OGC 07-118 Close to approval as OGC Best Practice document
This document describes the interfaces required to authenticate and authorise users in a federated system of OGC Web Services for Earth Observation. The document covers three high level scenarios:
- The orchestration of OGC Web Services as it may occur when (e.g.) Sensor Planning Service, Web processing Service and Web Coverage Service are provided by several cooperating organizations.
- The system of systems of OGC Web Services as it may occur when several organisations may concur and cooperate in the provision of instances of the same service within a federated service provision. Several relevant use cases are proposed within the GEOSS AIP.
- The security and EO products market scenarios which have high level requirements related to the user authentication as well as to the authorisation to the use of the OGC Web Services over geospatial (e.g. area of interest) and/or temporal parameters.