HF Radar Help

• Overview
• Navigation
• Selection Bar (located at the top of the map)
• Animation of Currents
• Ocean Current Vector
• Current Scale Color Bar

OVERVIEW

The NDBC HF Radar website is an interactive map with HF Radar data from various academic, meteorological, and oceanographic institutions, and contributing partners of the Integrated Ocean Observing System (IOOS®). The default displays a map of the United States and local coastal regions. The areas with HF radar information will display the data measured from the IOOS® sites graphically in the form of vectors. These are displayed in a color range depicted by the color bar scale on the right side of the map and are measured in centimeters/second. The default data is for a 25 hour average. These radar sites provide coastal-ocean surface current and wave information offshore out to 300 km. Surface current vector data will be updated hourly and displays realtime data information for each radar site, 24 hours per day, 7 days per week. This is a demonstration of the HF Radar display capability currently available. The HF Radar vector data has not been quality controlled.

NAVIGATION

• To pan (move the map), click and drag the map.
• To center and zoom the map on a location, double click the location on the map.
• To zoom the map in one level, click the "+" sign in the upper left corner of the map.
• To zoom out one level, click the "-" sign in the upper left corner of the map.
• To restore the original map boundaries and zoom, click the "Home" buttom in the upper left corner of the map.

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SELECTION BAR (located at the top of the map)

• The default view is the US Map with "vectors" and "25 hr avg" selected. This will overlay the data on the US Map in a vector format using a 25 hour average. Deselecting the "vectors" box will remove the display of the HF Radar data. To show the data again, reselect the "vectors" check box and the data will return.
• You can select an hourly report by deselecting the "25 hr avg" box. Then click on the drop down arrow beside the date and time box. Select any of the times back to the past 25 hours. This will display reported data for the chosen time period. To go back to the 25 hour average, reselect the "25 hr avg" box.
• To animate the currents, select the "time lapse" box. (See the section below for details on the animation of currents.)
• Clicking the sites check box will display icons of the radar sites on the map. Clicking these icons will display additional information about the individual radar sites.
• You may change the base map by selecting an option from the basemap drop-down list.
• Clicking the "?" icon will display this help page.

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ANIMATION OF CURRENTS

Clicking the "time lapse" check box will enable a loop that animates the currents through the 25 hour reporting time period. In order to start the animation, the "25 hr avg" box must be deselected and the "time lapse" box must be selected. This will start the animation, either at the current time or at a specified time from the drop down box. No matter where it starts, the loop will animate through the entire 25 hour time period. This feature will work at any zoom level and in any of the map views.

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OCEAN CURRENT VECTOR

Clicking any point on the map will open a pop-up containing the latitude, longitude, speed and direction of the nearest HF Radar current vector. At the bottom of the pop-up, the words "Show History" contain a link that will display additional historical information for previous time periods if available. Clicking on "Hide History" will close the additional information display. This pop-up can be closed by clicking on the "X" in the upper right-hand corner.

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CURRENT SCALE COLOR BAR

The Color Bar scale shows the centimeters per second of the current vectors and is located to the right of the map. The default is a range of 20-100 centimeters per second. Clicking "knots" will change the scale range to 0-~3.8 knots.

On a touch screen, this scale is a static legend. However, with mouse controls, the user may adjust the range as described below.

The range can be moved up or down the scale and the size of the range can be increased or decreased. To move the range up or down the scale place the mouse in the center of the range between the two white bars. When the double arrow or hand shows, click, hold down the mouse button and drag the range upor down to the desired location and release the mouse button to set the range. The location where the bar is placed will change the view values of the cm/s but will still display an 80 cm/s difference between the top of the range and the bottom of the range. The range can also be increased or decreased to show a greater or lesser variance in the displayed range. This can be accomplished by holding the mouse over either the top or bottom white bar in the scale. A double arrow will be displayed. Click, hold down the mouse button and drag up or down to change the range to the desired scale. This will increase or decrease the range to a greater or lesser range than the default of 80 cm/s.

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