Spatial and Temporal Extent¶
Spatial Bounds¶
Bounding Box and Description¶
Field |
Best Practice |
Example |
|---|---|---|
Bounding Box |
Use these fields to describe the rectangular box enclosing the area described by your dataset (or in which your data was collected). Describe the north and south bounds using positive degrees north latitude, and the east and west bounds using positive degrees east longitude. Enter the numeric value only. |
North: 60.43283 South: 59.72872 East: -146.84875 West: -148.00232 |
Description |
Use this field to provide a brief textual description of the area described by your datset or in which the data was collected. |
Montague Island, in the Central Gulf of Alaska |
Polygons, Points, or Lines¶
Field |
Best Practice |
Example |
|---|---|---|
Coordinates |
Use these fields to describe the polygons, discrete points, or linestrings that represents the areas described by your dataset or the bounds within which it was collected. Enter space-separated longitude,latitude coordinates for points representing the vertices of a polygon, the endpoints of line segments, and for distinct points. Be sure to enter your coordinates in the appropriate field for the geometric type you want to create, i.e. use the fields ‘Vertices of a Polygon’, ‘Points’, and ‘Line or Track’ to describe polygons, discrete point locations, or lines (or paths), respectively. Coordinates must have positive values for degrees north latitude and east longitude as negative values for south latitude and west longitude. Pro-tip: You probably don’t need these spatial types in your metadata. A bounding box is sufficient in almost all cases. However, if you think you do need these types, then have at it! |
Polygon (must have same first and last coordinate):
Points:
Linestring:
|
Name |
Use this field to provide a name for the area described by the polygon, linestring, or collection of points. |
Icy Bay sampling area |
Description |
Use this field to provide a brief textual description of the area described by your datset or in which the data was collected. |
External bounds of the sampling area in Icy Bay. Sampling station locations provided in ctd_stations_icybay_2017.csv |
Draw map¶
This section of the metadata editor provides a widget to help describe spatial extents by creating boxes, polygons, points, or polylines1 on a map. This will help you create spatial extents of various shapes much faster than entering each coordinate manually, but because these are all created by clicking locations on a map, these extents will necessarily be less accurate than those created with coordinates or bounds. If you opt to use the map drawing tool, a bounding box will be created from the furthest
Shape |
Best Practice |
|---|---|
Polyline* |
Use this option to create a spatial extent that is best described by a line or path. Examples of appropriate polylines as extents might be cruise paths and sampled transects. To draw a polygon on the map, click the button that looks like a line and then click on the map to place start- and endpoints for each line segment in the polyline. Double-click while placing the last endpoint to end the polyline. |
Polygon |
Use this option to create a spatial extent in an arbitrary shape. Appropriate extents might include sampling areas, species habitats, or watershed boundaries. To draw a polygon on the map, click the button that looks like a pentagon and then click on the map to place vertices. Double-click while placing the last vertice to close the polygon. |
Bounding Box |
Use this option to create a rectangular spatial extent. Appropriate uses of the bounding box as a spatial extent include studies or datasets with many discrete sampling locations of various shapes, or for which the exact locations or bounds aren’t very important or appropriate to include in the metadata. This might be the case for datasets describing the location of animal sightings, human artifacts, or fossils. To draw a bounding box on the map, click the button that looks like a square and then click and hold on the map to place one corner of your bounding box. While holding, drag to the the location of the opposite corner and release. |
Points |
Use this option to indicate distinct points in a spatial extent. Any sort of distinct sampling location could be indicated this way, though if this level of precision is needed from the metadata it would be better to add points using their coordinates on the ‘Polygons, Points, and Lines’ tab. If you do want to add discrete points to this map, zoom way, way in to ensure that you’re reasonably close to your point locations. When you’re ready, click the button that looks like a location marker (maybe it looks like an ice cream cone?) and click on the map where you want to place the marker. You’ll need to click the marker-button once for each point you want to place. |
*Polylines are just lines with angular bends, like a ‘Z’ or a ‘W’.
Time Period(s)¶
These fields describe the temporal coverage of your dataset; use them to document when data was collected, or what times or spans of time are described by the dataset. Select ‘Instance’ to document particular days or moments, and use ‘Range’ to document a span of time. Use the appropriate level of precision for documenting dates and times for your data. Remember, these are used for searching for and discovering your data.
Field |
Best Practice |
Example |
|---|---|---|
Range |
Enter the first and last dates described by your dataset. These may be the first and last dates for a cruise, the beginning and end of a sampling season, or the span of time represented in modeled results. |
start: 2014 06 01 -09:00 end: 2014 09 14 -09:00 |
Instance |
Use this field to document one or more discrete dates and times on which your data was collected or which are represented by your dataset. |
2015 08 15 2017 04 22 -09:00 13 18 |
Description |
Use this field to provide a brief textual description of the time range(s) or instance(s) documented in the field above. |
Summer sampling on PWS beach, 2014 Dates of opportunistic marine mammal observation efforts on vessel transiting between Whittier and Cordova |
Vertical Extent¶
These fields describe the vertical coverage of your dataset and assumes ‘meters’ as the units. This field is asking for heights rather than depths, so mean sea level is defined as 0, with the maximum value being the one farthest from the center of the earth and minimum being the value closest to it. Values beneath mean sea level should be negative.
If your data was collected on land and away from the coast, offset your max and min values to account for the elevation of your sampling site above or below sea level.
Field |
Best Practice |
Example |
|---|---|---|
Vertical Minimum |
Use this field to describe the lowest vertical level in your data. If this is below sea level, use negative values |
0, -134.56, 14 |
Vertical Maximum |
Use this field to describe the highest vertical value in your dataset. If this value is below the surface, use a negative value. |
15.16, 0, 100.00 |