Advanced search functionality

On the data discovery page, there are several ways to discover data. First, one can simply type a word or name into the query bar in order to search for that name or word among the discoverable resources.

Typing a word surrounded by quotes matches that particular word, e.g., “existing” matches only existing and not exists or exist.
Typing a phrase surrounded by quotes matches the whole phrase exactly, e.g. “hydrologic science” matches any resource with that exact phrase in its description, subject, etc.

One can combine these forms to search for multiple requirements at the same time. For example

Search string:	Selects resources for which:
Couch Tarboton	Couch and Tarboton are both mentioned.
Tarboton “hydrologic science”	Tarboton and the exact phrase “hydrologic science” appear.

Using fields

The above queries search all metadata for the resource for the terms listed. For more precise searches, one may also specify the field in the metadata that contains a desired term. For example:

Search string:	Selects resources with:
abstract:nitrogen	“nitrogen” appears in the resource abstract.
coverage_type:point	Resource contains data for a point on the globe.
availability:public	Resource is publicly available.

Coverage type and availability have limited options, as follows:

Search string:	Selects resources with:
coverage_type:point	Resource concerns a point on the globe.
coverage_type:box	Resource concerns a geographic box on the globe. Note: box coverages also have point coverage data for the box center.
coverage_type:period	Resource contains some kind of time series.
availability:discoverable	Resource existence is documented but access requires permission from the authors.
availability:public	Resource is publicly available.
availability:published	Resource is publicly available and has a DOI.

Note that:

Availability published implies public, which implies discoverable.
Coverage type box implies coverage type point, because the box center is recorded as a point.
To select resources containing time series, use coverage_type:period.
Resources containing multiple time series have coverage_type:box even though the data is for specific sites in the box.

Specifying dates

There are also several ways to specify dates of interest.

Search string:	Selects resources that:
created:2/1/2017	Were created on 2/1/2017
modified:2/1/2017	Were last modified on 2/1/2017
start_date:2/1/2017	Contain data with a start date of 2/1/2017
end_date:2/1/2017	Contain data with an end date of 2/1/2017

Date ranges

The above queries select resources for which a specific date is mentioned. It is often more useful to specify a range of dates, to wit:

Search string:	Selects resources that:
created>=2/1/2017	Were created on or after 2/1/2017
modified>=2/1/2017	Were last modified on or after 2/1/2017
start_date>=2/1/2017	Contain data with a start date on or after 2/1/2017
end_date>=2/1/2017	Contain data with an end date on or after 2/1/2017

There are four operators that may be used for ranges of dates.

Inequality	Meaning
>=	Greater than or equal to
>	Greater than
<=	Less than or equal to
<	Less than

Note that each one of these starts with a colon (:) and that a single : means “equal to”.

Multiple conditions may be separated by spaces on the query line. For example, the search string created>=2/1/2017 created<2/1/2018 selects resources that were created between 2/1/2017 and 1/31/2018.

Specifying geographic coordinates

There are two ways in HydroShare that geographic coordinates are used, both as the coordinates of a point on the earth and as coordinates of a box in which data is recorded. Additionally, the center of each box is recorded as a point. Thus all resources with box coverages also have point coverages, that point being the center of the box.

Geographic search queries include:

Search string:	Selects resources that contain data for a region of the earth whose:
east>-120.0	Location or box center > -120 degrees east longitude.
north>42.0	Location or box center > 42 degrees north latitude.
eastlimit>-120.0	East limit > -120 degrees east longitude.
westlimit>-120.0	West limit > -120 degrees east longitude.
northlimit>42.0	North limit > 42 degrees north latitude
southlimit>42.0	South limit > 42 degrees north latitude.

To specify a region, one can combine these. For example, the northwest corner of Nevada is listed as 42.05N, -120.06E, while the southeast corner is approximately 34.96N, -113.99E. Thus, to select those resources whose boxes are contained within Nevada, one could specify

westlimit>=-120.06 eastlimit<=-113.99 northlimit<=42.05 southlimit>=34.96

Compare this with:

east>=-120.06 east<=-113.99 north<=42.05 north>=34.96

which instead selects those resources whose box centers are within Nevada.