Through this tool bathymetric profiles are created using the elevations service from ESRI.
The elevation profile is obtained from a mosaicked digital elevation model (DEM) service of the entire globe, which combines primarily the following sources:
• SRTM (Shuttle Radar Topography Mission).
• GTOPO30 (from the United States Geological Survey - USGS).
• GEBCO (General Bathymetry Chart of the Oceans).
It has been resampled to the finest shuttle radar topography mission (SRTM) resolution of 92.5 meters (and will continue to be refined).
The data for this DEM is derived from the multiple sources listed below, with the original source data in its native coordinate system. Depending on the scale used, data from one of these datasets will be returned:
|
Source Data |
Source Native Pixel Size |
Approximate Pixel Size (m) |
Primary Sources |
|
England 2m |
2 meters |
2 |
|
|
Wales 2m |
2 meters |
2 |
|
|
Netherlands 3m |
3 meters |
3 |
|
|
Austria 10m |
10 meters |
10 |
|
|
Denmark 3m |
3.2 meters |
3 |
|
|
Denmark 10m |
10 meters |
10 |
|
|
Finland 3m |
3 meters |
3 |
|
|
Finland 10m |
10 meters |
10 |
|
|
Spain 5m |
5 meters |
5 |
|
|
Spain 10m |
10 meters |
10 |
|
|
Norway 10m |
10 meters |
10 |
|
|
OS Terrain 50 |
50 meters |
50 |
|
|
FEMA LiDAR DTM |
3 meters |
3 |
|
|
NED 1/9 arc second |
0.000030864197530866 degrees |
3 |
|
|
NED 1/3 arc second |
0.000092592592593 degrees |
10 |
|
|
NED 1 arc second |
0.0002777777777779 degrees |
31 |
|
|
NED 2 arc second |
0.000555555555556 degrees |
62 |
|
|
SRTM 1 arc second |
0.0002777777777779 degrees |
31 |
|
|
SRTM 1 arc second DEM-S |
0.0002777777777779 degrees |
31 |
|
|
SRTM v4.1 |
0.00083333333333333 degrees |
93 |
|
|
EarthEnv-DEM90 |
0.00083333333333333 degrees |
93 |
|
|
GMTED2010 7.5 arc second |
0.00208333333333333 degrees |
232 |
|
|
GMTED2010 15 arc second |
0.00416666666666666 degrees |
464 |
|
|
GMTED2010 30 arc second |
0.0083333333333333 degrees |
928 |
|
|
GEBCO |
0.0083333333333333 degrees |
928 |
Source: ESRI
When the user launches this tool, the map region displays the "Digitize a Transect" panel.
This panel allows the user to select the x-axis length unit. The user can select between kilometres, nautical miles, metres, miles, yards, and feet. The unit of measurement for the y-axis is determined by the x-axis value. If a metric system unit is selected, the value is in meters; if another unit of measure is chosen, the value is in feet.
By clicking the "Draw Profile" button, the user can draw a polyline on the map, adding vertices with a single left click of the mouse; double click to complete. As a result, a new panel featuring the profile graph will appear beneath the main map.
When the mouse is moved over the bathymetric profile, the depth information for that point is displayed in a line drawn on the map.
With the Free Hand Profile button, the line drawn on the map displays the geometry required to obtain information from the elevation service; this is accomplished with a simple mouse movement rather than clicking to add vertices. To finish, as in the other case, double-click the left mouse button.
It is possible to load a comma-separated values (CSV) file containing a list of points and then draw a polyline with these points as nodes to obtain bathymetric profiles. Simply drag and drop the CSV file over the map, and the tool will calculate the deep profile.
The csv file requires only three fields: longitude (lon), latitude (lat), and the final field (field1), with the order of the points matching the order in which the polyline will be drawn.
You can download an example file by clicking the "CSV example" button.
