LightListManager User GuideBasic Stuff - The Light List Data Display
Most of the LightListManager main form is taken up with the display of the contents of one Light List file. Fig. 1 is of the maximized main form to show as much of the data display as possible. Click on the image to display it at full resolustion in a separate browser tab.
When an entry in the Volume/District list is clicked, the contents of the most recently downloaded file for that entry is displayed in the form. This display consists of the most significant fields in the data records. The fields are identified by the column headers as listed below:
- Volume: The volume ID for the displayed light List. Where, V3 = volume 3 and D07 = USCG District 7.
- LLNR: The Light List number for the entry. These numbers are unique to the entry volume, but may be duplicated in other volumes. The combination of the volume ID and the LLNR uniquely identifies each entry across all volumes. There are some lights that have two entries in a volume under the same LLNR. These are lights that show different day and night characteristics. In this case the program appends the LLNR with "-Day", "-Night" or -"Both" to differentiate the duplicate LLNR entries.
- Name: The descriptive name of the light or mark.
- Type: This designates whether the light or mark is maintained by the USCG ("FD") or maintained by another government agency or a private concern ("PA").
- Latitude and Longitude: The next two columns specify the location of the light or mark to 1,000 of a second.
- Characteristic: If the entry is for a lighted mark, the characteristic of the light is shown. The program provides several means to decode the entries in this field. If the entry is not lit (day mark) this field is blank.
- LNM Status: If the latest Local Notice to Mariners contains an entry for any of the lights in the display, that status is displayed in this column. Fig 1 does not show this column as the LNM status had not been aded tot the display when the screen image was captured.
- Height: If the entry is for a light or mark that is elevated well above sea leval, the height is shown in feet.
- Range: If the entry is lit and elevated, the estimated range of the light is shown in nautical miles (nm).
- Structure: This field describes the appearance of the light or mark.
- RACON: Some lights are also Radar Beacons. When a RACON detects a radar pulse from a ship's radar it transmits a morse code letter. RACON capable radar displays will show this morse code letter allowing the light to be identified on the radar screen. If a Light List entry is a RACON equiped light, the Morse Code letter is shown in this field.
- Remarks: Additional information on the light or mark
Light Details Form
The Light List records contain more data than can be displayed without using the horizontal scroll bar at the bottom of the listing. Right clicking on an entry and selecting "Display Details" from the popup menu, as shown in Fig. 2., will activate the Light List Details form, which shows all data for one Light. If you select more than one entry and then right click to display the details, each of the selected entries will be in the drop down list on the Details Form.
Some lights have different Night and Day characteristics. For those lights the Details Form provides a drop down list for the different characteristics. In the Main form data display those lights will appear twice in the list, once for the Day characteristic and once for the Night characteristic. Each of the entries will show the LLNR appended with "-Day", "-Night", or "-Both" to distinguish which characteristic applies to the list entry. These two entries are concantenated into single entry on the Details form using the drop down list for the different characteristics. Most lights have a single characteristic active only at night or both day and night, and therefore have a single entry in the Data Display list on the Main form. The most common type of lights that has multiple characteristics are range lights that may use a brighter light at a different height during day light hours. Some range lights exhibit a color light at night and a white light during the day.
Light Characteristic Display Form
If the entry or entries selected include any lighted marks, then the "Display Characteristics" popup menu item can be selected. This will open the Light Characteristic Display form. In addition to the text details on each light selected, the form also provides a graphic depiction of the light characteristic. the Lighthouse depicted (Point No Point on the Chesapeake Bay) is not meant show the actual light, but just the light characteristic (sequence and colors). As with the "Display Details" form, the "Display Characteristics" form concantenates multiple charaacteristics into a drop down list.
Light and Daymark Definitions from the Help Menu
The Help menu contains another source of information on light characteristic as well as dayboard structure. Click the "Characteristics and Structures" menu item. This opens the Characteristics and Structures of Navaids form, which has two tabs, one for "Light Characteristics" and one for "Day Board Structures".
The "Light Characteristic" tab contains a list of the general light characteristic codes used to describe the visual appearance of each light. If you click on one of the entries in this list a definition of that characteristic is displayed. There is also a button labeled "Display USCG Doc". Clicking this button will display the page from the USCG published Light List documents that provides similar definitions.
The "Dayboard Structure" tab provides descriptions of navaids from the letter codes used to identify some types of navaid in the light lists structure field, and (more commonly) on nautical charts. These navaids can be either lighted or unlit. The letters define the purpose and color or colors of the navaid. There are three columns on the left side of the form with the sets of letter used to describe the structures in the Light Lists. The first list contains the letters that define the function of the mark (e.g., "J" for junction). The second list contains the letters that represent the color of the dayboard (e.g., "Y" for yellow). Some navaids. display more than one color (e.g., RW for Red and White). The third list are additional designations for navaids on the Intra Coastal Waterways (e.g., AICW, Atlantic Intra Coastal Waterway). In Fig. 6 the letters "KRW" have been selected and the form defines this navaid as a red range mark with a white stripe.
Buoys, lighted or not, generally have the color spelled out in the structure field (e.g., "Red") rather than using letter codes.