NAVPAK Copyright (c) 1984 - 1997 32 bit version COMMAND REFERENCE USER INTERFACE Charts can be scrolled with the mouse (or other pointing device) on the scroll bars or with the arrow keys, Home, End, PgUp, and PgDn keys, or by indicating on the "Area Map" located in the "Screen" menu. The secondary button of the mouse will activate a pop-up menu. The dialog boxes are programmed with the following characteristics: 1. The edit boxes within the dialog boxes accept whole numbers and decimals. It would be normal practice to enter whole numbers for degrees and decimal numbers for minutes, however you could enter decimal degrees. 2. The "Intercept" edit box will recognize a negative number, which is equivalent to an intercept plotted "away" from the geographical position of the celestial body. 3. All other edit boxes will ignore the minus sign, because the sign is set with the north, south, east and west buttons. 4. There are tab stops where user input is required, so that you can use the tab key to jump from box to box. 5. The default control is: OK, DRAW, or PLOT, which will activate when you hit the "Enter" key. Exception: the "Time, Speed, Distance" dialog box default control is Cancel. PLOTTING SYMBOLS NavPak will generate and display way points, track points, radar targets, radar cursor position and ownship position. Way points are diamond shapes, track points are circles connected with lines, radar targets are red squares, the radar cursor is a square with a cross, and ownship position is a circle with a cross. IDENTIFYING SYMBOLS Way points, track points and radar targets can be identified in two ways. One way is to double-click near a point with the left mouse button. A dialog box, corresponding to the point type will appear with information about the point. Another method of identifying these points, is to digitize with a single-click near a point, then select the point type from the NMEA menu. This will display a dialog box with a Search button. When the Search button is selected, it will display information about the point. IMAGE DISPLAY NavPak-32 will display .bmp and .rle files. These can be generated from BSB (.kap), NOS/GEO, or NDI charts using MapSetup, or they can be bitmaps from other sources. When Mapsetup is used to convert a BSB, NOS/GEO or NDI chart to a .bmp or .rle bitmap, it will generate three copies of the chart. One copy is full size at the resolution chosen, another other copy is half size, and the third copy is quarter size. The half size, and quarter size bitmaps provide very fast scrolling and zooming, and quick generation of the "Area Map" with low memory requirements. When you select " Zoom 50% ", NavPak-32 will look for the half size bitmap with the same name as the loaded image, with the extension: .b50 which indicates a 50% .bmp, or .r50 which is a 50% .rle. When you select " Zoom 25% ", NavPak-32 will look for the quarter size bitmap with the same name as the loaded image, with the extension: .b25 or .r25, which is the quarter size .bmp or .rle file. MapSetup will generate the three images simultaneously and append the extension .b50 or .r50, and .b25 or .r25 to the reduced images during the "KAP or NOS/GEO to BMP or RLE" conversion and store all three image files in the directory specified along with the script file. See the file "MapSetup.txt" for more info about file conversion. If the half size or quarter size bitmaps are not present in the same directory as the main image, then a message box will appear with the option to build them. It will take a few minutes to build a reduced size bitmap. When it's finished, a message box will appear which gives you the option of saving the reduced size bitmap on disk. If you choose to save it, then it will quickly load and display when you need it. The "Area Map" will generate quickly from the quarter size bitmap, so it's not necessary to store this on disk. SCREEN POSITION and SCALE When loading a bitmap into NavPak, the setup will be done automatically if a script file was written using MapSetUp. If you are using NavPak without a chart, digitize a point in the middle of the screen to represent your assumed position. Go to the "Screen Setup" dialog box and enter the latitude and longitude of the digitized point. If you are in the north and west hemispheres, then it's not necessary to select the north and west buttons in the "Screen Setup" dialog box. Scale is expressed in pixels per minute. A scale setting of 1 will result in 1 pixel per minute at the equator, or on any other great circle. On a 640 x 480 screen you will get a plotting area of approximately 614 x 424 miles, taking into account 56 pixels for the title bar, menu bar and horizontal scroll bar, and 26 pixels for the vertical scroll bar. With a scale setting of 2, you will have a plotting area of approximately 307 x 212 miles. The scale can be set to accommodate world maps and harbor charts. GRID There will be some grid lines on the bitmap and you can turn on the grid on the screen, independent of the bitmap. The grid is a useful check of your screen settings to see if it matches the grid of the chart. The grid can be set to any interval using the Grid dialog box, accessible from the Screen menu. AREA MAP The area map is a miniature copy of the whole image which is loaded. It provides an overall perspective and a convenient way to scroll the main window. If you are receiving NMEA data (GPS), then your position will be plotted on the area map as a flashing symbol. On the area map, your screen position will be shown as the red frame. If you digitize a point on the map with the main pick button (left mouse button), a green frame will appear. When you click the secondary pick button (right mouse button), the main window will scroll to the green frame. DRAW MENU Line: This can be used to plot straight lines between two digitized points. Text: Digitize a start point for text before choosing this from the menu. A dialog box will appear where you can type in a 16 character string. Chain Line / Boundary: This can be used for plotting, or as a color fill boundary. Points digitized after choosing this menu item, will define the chain line. You can back-up all the way to the beginning using "Undo Chain", in the Edit menu. Sketch / Boundary: This is for drawing curved lines, or as a color fill boundary. It is used by holding down the pick button, while moving the pointing device (known as click and drag). Select "Draw Off" in the menu to disable drawing and markers. MARKERS Select a marker symbol from the menu. The symbol can be placed on the screen with the left mouse button (main pick button). You can record 306 markers per metafile. Drawing with the grid, drawing tools and markers above is an overlay which can be saved at any time as a .wmf file. The bitmap will not be modified by NavPak. You can modify bitmaps to update charts using a paint program. PROJECTION NavPak for Windows is based on Mercator projection coordinates and the World Geodetic System ellipsoid (WGS). This is compatible with almost all nautical charts, topographical maps, and street maps. Older charts and maps can be adjusted to the WGS datum with datum shift values. NavPak is designed to display Mercator projection charts and maps and will automatically adjust to projection parameters, as long as the chart or map is a Mercator projection with parallels and meridians perpendicular to each other. NavPak provides mouse coordinates, grid spacing, and plotting functions up to 66 degrees, north or south . Celestial sight reduction, star and planet identification, measure, and great circle routines are designed to work through 360 degrees. TOOLS MENU VARIATION... Magnetic variation will be set by the setup script file when a bitmap is loaded. A small scale bitmap can have many variations. In this case the Variation dialog box can be used to set local variation. The following functions are corrected for variation: Bearing, AdvLOP, Star Identification and Line (relative). When using these functions, your variation will be shown in a read only box in the dialog box as a reminder that the result will be corrected for magnetic variation. The measure function always gives true and magnetic directions. The celestial plotting routines are not dependent on variation. BEARING... After taking a bearing with a hand bearing compass or radio direction finder, digitize the observed object on the screen, then choose Bearing from the Tools menu. After you type in the bearing, select OK, the bearing will be drawn. AdvLOP... To advance a line of position, digitize 2 points on the line which you want to advance, choose AdvLOP from the Tools menu, After you type in the bearing, select OK, a segment of the line of position will be drawn paral- lel to the 2 digitized points. Note that this can be used in situations where celestial observations must be spread over a sufficient period of time to obtain useful LOPs', or it can be used to adjust a line of position for estimated current and leeway. This routine is based on a great circle formula which will give accurate results at high latitudes. LINE... The line function is used to draw a line, of a specified length, at a specified angle from the last digitized point. This provides the reciprocal function to the Bearing function (except that this is based on spherical trig and the bearing function is based on plane trig). It can be used to keep track of deduced reckoning, such as multiple tacks. This routine is based on a great circle formula which will give accurate results at high latitudes. MEASURE... Digitize 2 points on the screen, then choose Measure from the Tools menu. The dialog box will display the distance and direction (true and magnetic). This routine is based on a great circle formula which will give accurate results over long distances. Calc TSD... Time-speed-distance calculator: Enter values for 2 of the 3 arguments and then select the calculate button for the third argument. GREAT CIRCLE... digitize 2 points on the screen, choose Great Circle from the Tools menu, and push the DRAW button or hit carriage return and the great circle will be drawn. This circle can be used to find the course to steer, find waypoints, or determine shipping lanes. This function draws 30 segments per great circle. The registered version includes a world bitmap which is useful with this function. CELESTIAL Sight Reduction... The sight reduction routine provides high precision altitude corrections for all celestial bodies above 5 degrees observed angle. From the Nautical Almanac you provide: G.H.A. (Greenwich hour angle) Dec. (Declination) S.D. (Semidiameter for sun and moon) H.P. (Horizontal parallax for moon) The phase correction for planets (shown as "Additional corrn" in the Nautical Almanac altitude correction tables) can be ignored. If you choose to add it, then it can be combined with the sextant angle. Also the corrections for non-standard pressure and temperature can be ignored for sights below 10 degrees, except under extreme conditions. If you choose to add these corrections, then they can be combined with the sextant angle. Your assumed position can be entered into the edit boxes or set to the last point digitized before opening the dialog box. Enter the necessary information and then select the Solve button to see the azimuth and intercept. When you're satisfied with the azimuth and intercept displayed, select the Plot button, and the LOP and azimuth will be plotted. The azimuth line is plotted using a great circle formula, for accuracy at high latitudes. The LOP plotted will be recorded on the screen metafile. Example: 1. Digitize a point near the center of your screen. 2. Open Celestial Sight Reduction dialog box. 3. Push "Set" button to set assumed position to last point. 4. Push "Solve" button to see the azimuth and intercept. 5. Change the intercept to about + or - 10. 6. Push the "PLOT" button and the azimuth and LOP will be plotted. Star and planet identification... For this procedure, enter whole degrees of sextant angle, G.H.A. of Aries, and bearing. Your assumed position is automatically set to the last point digitized before opening the dialog box. The resulting S.H.A. and declination are used to find a match from the S.H.A. and declination of the navigational planets and stars given in the Nautical Almanac. SCREEN METAFILE The screen metafile is created when the program is started, and will record all your drawing, plotting and text, and redraw it as you scroll. The screen metafile can be used in the following ways: 1. Save it, and it will accumulate everything drawn since NavPak was started. See File menu. 2. Undo items drawn or plotted. See Edit menu. 3. Clear screen metafile. See File menu. For more information about metafiles, see "Metafile.txt". Do not rely solely on electronic aids for navigation. Before going offshore, you should have paper charts, sextant, chronometer, almanac, sight reduction tables and a hand bearing compass. /******************** end NavPak.txt *******************************/