NOS Hydro Search Criteria Selection - You can Search the NOS Hydrographic Surveys
database by choosing among various search criteria below. Search will return those surveys which meet your criteria. Normally the
area will be automatically set from the previous page (NOS Map Viewer), but this area can be changed. You can also start the
process from this page. At the completion of the Search you will have direct access to survey metadata (HYD93 Format Documentation Headers)
and survey plots (polygons of survey coverage) for those surveys resulting from your Search. You may then continue on to download the data.
Use the Advanced button to make more Search criteria available.
Your Operating System - The type of computer you are using is, in most cases, automatically determined.
Change this only if you wish to output files to a format different from the one
which was determined for you.
Lat/Lon Area Bounds - Choose the latitude/longitude boundaries of your Search area in decimal degrees or in degrees,
minutes and seconds. Switch between the 2 above methods with the button in the center of the lat/lon box.
Latitudes must be between 90 degrees North and 90 degrees South.
Longitude values must be between 180 degrees West and 180 degrees East (or -180 and +180).
Your area may not cross both 0 degrees and 180 degrees (e.g. 120E to 120E will not work).
If you wish your area to span the entire globe longitudinally, you should choose bounds of 180W to 180E (or -180 to +180),
or just click the World button. This has the effect of not using area as a Search criteria.
Use the Line or the Polygon(s) button to re-do your Search area as a (intersecting) line or as (multiple) polygons.
Entering/Editing Intersect Line in the Text Box -
The lat,lon pts in the text box deliniates a line which will result in a Search hit whenever the
line intersects a survey's area.
Enter each point of your Search Area(s) on a separate line, separating the latitude and
longitude with a comma (use no spaces). Example:
5.932 deg North 172.000 deg East
12.500 deg North 150.370 deg West
30.000 deg South 142.600 deg West
This line would be entered as:
Use the Rectangle or the Polygon(s) button to re-do your Search area as a box or as (multiple) polygons.
Entering/Editing Polygon(s) in the Text Box -
Enter each point of your Search Area Polygon(s) on a separate line, separating the latitude and
longitude with a comma (use no spaces). If you have more than one polygon, use the "Enter"
key to place a blank line between each of the polygons. If a polygon segment is more than 180 degrees longitude,
the segment will go around the world in the shortest (wrong) direction,
therefore add an extra polygon point on such segments.
2 areas, one a triangle and one a rectangle,
are defined as follows:
5.932 degrees North 172.000 degrees East
12.500 degrees North 150.370 degrees West
30.000 degrees South 142.600 degrees West
60 deg 30 min North 150 deg 30 min East
60 deg 30 min North 160 deg 20 min East
50 deg 15 min North 160 deg 20 min East
50 deg 15 min North 150 deg 30 min East
They would be entered as:
You may enter up to 20 areas with up to 22 points (lat/lon
pairs) each. However, the total number of points is restricted to
Use the Rectangle or the Line button to re-do your Search area as a box or as an Intersect Line.
Platform(s) - Choose Platform(s) to Search for. Choosing ALL PLATFORMS causes Search to ignore plaform criteria.
Be aware of the entries MULTIPLE SHIPS and UNKNOWN SHIP, and thus the possiblilty of missing surveys when searching by platform.
Year Data was Collected - Use
this option to restrict your Search to data collected during a
specific span of years. Enter beginning and ending years to
define a range of years. Enter 4 digits for year (e.g. 1994). If
you only want to find surveys which contain data in a single
year, simply repeat the beginning year as the ending year. If any
part of a survey took place within the range of years you
specify, that survey will match the year criteria.
DATE Added to System - Restrict your SEARCH by the date the surveys were assimilated into this System.
This give you the opportunity to easily check for new data. Enter beginning and ending dates in the format YYYYMMDD (year-month-day) to
define a range of dates.
Survey Id(s) - Enter NOS Survey Id(s) to restrict the Search to specific surveys. Search will make some attempts to match non-exact Id(s) with the Id(s) in the
NOS Database by ignoring case, by ignoring some non-relevant zeros, and by attempting to match surveys with suffixes
in the Id.