HAM Radio 1

home *** CD-ROM | disk | FTP | other *** search

/ HAM Radio 1 / HamRadio.cdr / fax / wxfax / faxguide.doc < prev next >

Wrap

Text File | 1990-07-05 | 55KB | 1,717 lines

WeatherFAX Weather Facsimile for IBM and Compatible Personal Computers USER'S GUIDE First edition March 1990 Copyright 1990 Jerry Dahl 6404 Lakerest Court Raleigh, NC 27612 WeatherFAX User's Guide Page 1 TABLE OF CONTENTS ───────────────── GENERAL INFORMATION ............................ 2 Introduction Purpose and Goals License information The Software The Author SUPPORTED CONFIGURATIONS ....................... 4 Hardware Software INSTALLATION INSTRUCTIONS ...................... 5 Installing the WeatherFAX card CONFIG.SYS Modifications AUTOEXEC.BAT Modifications Copying the diskette Starting the Program GETTING STARTED ................................ 7 Getting help information Testing the card Selecting your printer type and display mode Connecting your computer to your fax receiver USING WEATHERFAX ............................... 9 Adjusting the page alignment Getting the image Viewing the image Printing the image Saving the image to disk ADDITIONAL INFORMATION ......................... 18 Calibrating the card Using Expanded Memory (LIM 4.0) Using extended VGA (800 X 600 Pixel) mode Sources for weather facsimile Decoding RTTY WeatherFAX specifications IF YOU HAVE DIFFICULTY ......................... 23 ADAPTER/SOFTWARE AVAILABILITY .................. 24 TRADEMARKS USED IN THIS GUIDE .................. 25 WeatherFAX User's Guide Page 2 GENERAL INFORMATION ─────────────────── INTRODUCTION These instructions explain how to install and use the WeatherFAX weather scan converter and software. You may print this guide with your printer by typing the following command from the DOS command line: COPY FAXGUIDE.DOC LPT1 This scan converter and software can be used with your IBM or compatible personal computer. With the proper receiving equipment and antenna, your computer will be able to capture, enhance, save and print not just black and white, but gray-scale weather-facsimile images received on the HF, VHF and UHF bands. Users of this Automatic Picture Transmission (APT) imagery include military and commercial meteorologists, ships at sea, scientific observers, educators, and amateurs. The system features include: o Direct weather-satellite imagery, including: geo- stationary earth-orbiting satellites (GOES APT/WEFAX, METEOSAT), polar-orbiting satellites (NOAA 9/10 APT IR/Vis, Soviet Meteor), HF-FM NAFAX, and similar APT formats. o Expanded memory support. You can capture images with a wide variety of resolutions. The size of the captured image is limited only by the amount of RAM in your computer. To view images larger than your monitor can display at one time, you can scroll up, down, left, and right. o Incoming pictures can be saved directly to disk. Either the Tag Image File Format (TIFF) or Graphical Interchange Format (GIF) can be selected to allow the images to be used with other graphics-based software. o Print images with 16-level gray scale on a wide variety of printers including 9- and 24-pin dot-matrix printers and laser printers. o All standard graphics cards are supported including CGA, MCGA, EGA, VGA, and the extended 800 x 600 mode. o Histograms, enhancement, zoom, scroll, gray scale, 256,000+ colors, real-time acquisition/display. Complete RGB level intensity control for each displayable color. Contrast and brightness are fully adjustable. 4 user-settable imagery enhancement WeatherFAX User's Guide Page 3 curves. Enhancement is retroactive and instantaneous. o Frequency-shift-keyed (FSK) radioteletype (RTTY) decoding. In addition to pictures, you can receive land-based weather-station Baudot RTTY transmissions. o Automatic gain-lock circuitry. The optimum gain value for WEFAX-signal reception is statistically calculated. This provides better and more consistent pictures than either automatic gain control (AGC) or fixed-gain circuits. o No need for external test equipment to test and calibrate the board. The software and special circuitry on the board allow the computer to automate the testing and calibration. o Unattended operation. Image capture can be fully or partially automatic, including APT start tone detect, sync, image save to disk, APT stop tone detect, and cycle repeat. LICENSE INFORMATION Your right to use WeatherFAX This software is copyrighted in order to control its orderly development. However, you have the right to use the program for private, non-commercial purposes without further permission. That is, you can copy it, use it, and share it so long as you do not charge any money for it other than the cost of the disk or other transfer medium, not to exceed $2. Please note that you MUST return a completed registration form as contained in the file REGISTER.DOC as a condition of using WeatherFAX. Suggested Contributions In order to cover expenses associated with the development and distribution of WeatherFAX, such as equipment, software, postage, supplies, and telephone calls to users, I suggest a voluntary contribution of $10 (or whatever is affordable to you) for each copy of the program. THE SOFTWARE WeatherFAX is written in Turbo C* version 2.0. The development of the program began in early 1986, and has gone through several revisions. New versions will be released as features are added and corrections are made to previously released versions. WeatherFAX User's Guide Page 4 The latest version can be obtained by sending a FORMATTED (360-kbyte) 5-1/4" diskette (or 3.5" diskette) and a STAMPED, SELF-ADDRESSED diskette mailer to the author at the address below. The request should also be sent with sufficient postage that it does not arrive with postage due! Also a Shareware contribution makes the author whistle while he works making your copy! THE AUTHOR The author can be contacted by mail at the following address: 6404 Lakerest Court Raleigh, NC 27612 For a mail reply, please enclose a self-addressed, self-stamped envelope. Credit must also be given to the many users who have made suggestions for improving the program. Many of their suggestions have been incorporated into WeatherFAX. SUPPORTED CONFIGURATIONS ──────────────────────── MACHINE REQUIREMENTS o WeatherFAX Card o IBM PC or compatible computer that uses the standard PC-bus architecture. o RAM (Random Access Memory): - 512 kbytes or more of memory: In most configurations, approximately 190 kbytes of memory is required for DOS, the WeatherFAX program and drivers loaded by CONFIG.SYS. All of the remaining memory is available for image storage. - Expanded Memory (optional) LIM 4.0 expanded memory allows up to 16 Mbytes for image storage. Requires both expanded memory and a LIM 4.0 software driver. o A graphics monitor and video adapter card including - Color/Graphics Adapter (CGA) - Enhanced Graphics Adapter (EGA) - Multi-Color Graphics Array (MCGA). - Video Graphics Array (VGA) - Extended VGA (800 x 600 pixel resolution) WeatherFAX User's Guide Page 5 o One diskette drive (one of the following): - 5.25-inch drive (360 kbytes) - 3.5-inch drive (720 kbytes). o Fixed disk (optional) o Printer: (optional) Printer types and print resolution - dots per inch (dpi) ──────────────────────────────────────────────────────── - All standard 9-pin dot-matrix printers (120 dpi) - All standard 24-pin dot-matrix printers (180 dpi) - IBM Pageprinter 3812 (240 dpi) - PCL command compatible printers (300 dpi) o Receiving equipment and antenna for the frequencies you want to cover. PROGRAM REQUIREMENTS To run the WeatherFAX software, you need: o IBM Personal Computer Disk Operating System (DOS) Version 3.0 or later INSTALLATION INSTRUCTIONS ───────────────────────── INSTALLING THE WEATHERFAX ADAPTER Refer to the Guide to Operations for your computer for instructions for installing cards. You will need to turn the computer off and remove the cover from the computer to insert the fax card into an unused card socket. CONFIG.SYS MODIFICATIONS No changes to CONFIG.SYS are normally needed. However, if you ever get the error message "DRIVE NOT READY" when retrieving very large files (1 Mbyte or larger), the reason may be the assignment of an insufficient number of DOS buffers. Try increasing the number of buffers by adding the statement BUFFERS=64 to the CONFIG.SYS file. AUTOEXEC.BAT MODIFICATIONS NOTE FOR USERS HAVING THE ORIGINAL IBM CGA DISPLAY ADAPTER. (Does not apply if you are using a PS/2* computer or a VGA or EGA Display adapter). The CGA adapter ROM does not include the entire graphics character set. You will need to load the DOS graphics- WeatherFAX User's Guide Page 6 character-set driver GRAPHICS.COM into memory. The driver is available on the DOS diskette. Add the statement GRAPHICS.COM to your DOS AUTOEXEC.BAT file to load the driver every time you start your computer. If GRAPHICS.COM is in a subdirectory, supply the necessary path information on the driver statement. For example: C:\DOS\GRAPHICS.COM When using this program, make sure your AUTOEXEC.BAT file is "clean." Some terminate-stay-resident (TSR) programs--especially those that control screen functions (such as screen blanking) may interfere with the proper operation of the software. If you experience difficulty when running the fax software, check your AUTOEXEC.BAT file first. COPYING THE DISKETTE Copy the WeatherFAX diskette and save the original diskette in a safe place. You can copy the diskette to either a hard disk or to another diskette. Refer to your DOS manual for instructions for copying diskettes. The WeatherFAX program is not copy protected. STARTING THE PROGRAM Start the WeatherFAX program by typing FAX.EXE from the DOS command line. Optional Command Line Parameters: ┌───────────────────────────────────────────────────┐ │ Syntax: FAX [options] │ │ Where options are: │ │ │ │ /E = Use Expanded (EMS) memory if installed. │ │ Requires LIM 4.0 driver. │ │ /C = Use conventional memory. │ │ /A = Go into acquire mode │ │ /Ffile = Go into acquire mode, save next image to │ │ disk with the given file specification, │ │ then exit to DOS. │ │ /Hxx = BIOS display mode for 800x600 resolution │ │ mode. See section 'Using Extended VGA │ │ (800x600 Pixel) mode'. │ └───────────────────────────────────────────────────┘ NOTE: Program will automatically use EMS memory if the available EMS memory size is greater than the conventional memory size. Examples: C:>FAX /FC:NEWFILE.TIF Allows unattended operation. Program automatically goes into capture mode, stores next image into WeatherFAX User's Guide Page 7 disk file C:NEWFILE.TIF, then exits to DOS. This allows you to use an external timer to start the computer at a preselected time. A batch file would then instruct WeatherFAX to save the next image into a specified file. C:>FAX /H54 Enables 800 x 600 pel resolution mode for ATI VGAWonder compatible card. See the section: Using Extended VGA (800 X 600 Pixel) mode. GETTING STARTED ─────────────── GETTING HELP INFORMATION Help information is available anytime you see 'F1=Help' displayed on the screen. You can access Help by pressing the 'F1' key on your keyboard. You can quit viewing Help by pressing the 'Esc' key on your keyboard. TESTING THE ADAPTER Test the fax adapter by using the Test option on the Main Menu. The various tests will indicate whether the adapter is operating within its correct operating region. If any of the tests indicate that the adapter needs calibration, refer to the section: Calibrating the adapter. Static Test This test is used to check for normal operation and calibration. The nominal parametric values on the adapter are displayed. All of the marks should be in the 'OK' region. Dynamic Test A test signal is applied to the input of each function and the output is checked for correct operation. The Start and Stop Detectors are tested for both ON and OFF states. The FM and AM Detectors are tested to verify linear operation. AM Graph Test A test signal is applied to the AM Detector at various amplitudes and the output linearity is displayed. The graph line should be straight and sloping upward. FM Graph Test A test signal is applied to the FM detector at various frequencies and the output linearity is displayed. WeatherFAX User's Guide Page 8 The graph line should be straight, sloping upward, and centered between 0 and 256. SELECTING YOUR PRINTER TYPE AND DISPLAY MODE Go to the fax menu to specify the Display Mode and Printer type. You can select a compatible printer type from the list of supported printers. Check your printer documentation to determine which of the supported types that it emulates. Printers supported and print resolution (dots per inch) ┌──────────────────────────────────────────────┐ │ Epson compatible 8-pin printers (120 dpi) │ │ - Epson FX, MX, RX, LX series │ │ - IBM Graphics or Proprinter │ │ - Okidata 192I+, 193I+, 292, 293 │ │ - Okidata in IBM-compatible mode │ │ - Panasonic KX-P1080i, P1091i, P1093 │ │ - Cannon PW-1156A │ │ - Citizen MPS-25 │ │ - Star Micronics: Gemeni 10X │ │ │ │ Okidata compatible 8-pin printers (120 dpi) │ │ - Okidata 192, 193 │ │ │ │ Apple ImageWriter II (160 dpi) │ │ │ │ Epson 24-pin compatible printers (180 dpi) │ │ - Epson LQ series │ │ - IBM Proprinter X24 and XL24 │ │ │ │ Toshiba 24-pin compatible printers (180 dpi) │ │ - Toshiba P321, P341, P351 │ │ │ │ IBM Pageprinter 3812 (240 dpi) │ │ │ │ PCL command compatible printers (300 dpi) │ │ - HP LaserJet series II │ │ - HP DeskJet │ │ - Apple LaserWriter II │ │ - IBM LaserPrinter │ └──────────────────────────────────────────────┘ NOTE: If you are using a printer attached to the serial port (COM1), you need to set up the serial port using the DOS MODE command before starting the WeatherFAX program. These commands could be placed in your AUTOEXEC.BAT file. 1) Set the baud rate and other parameters with the DOS MODE command. (e.g., MODE COM1:96,N,8,1,P) WeatherFAX User's Guide Page 9 2) Redirect LPT1 to COM1 with the DOS MODE command (e.g., MODE LPT1=COM1) 3) Start WeatherFAX program and set the Printer Destination in the SETUP MENU to LPT1 Serial port printers are usually configured for either 7-bit or 8-bit graphics mode. Be sure that the printer is configured for 8-bit mode. Otherwise, the printed sample will have a blank row (space) every 8 lines. CONNECTING YOUR COMPUTER TO YOUR FAX RECEIVER Use a two-wire cable to attach the fax adapter to your fax receiver. The cable should have a standard 3.5-mm phone plug on the end that plugs into the adapter. Plug the cable into either the receiver earphone jack or fax output jack. USING WEATHERFAX ──────────────── ADJUSTING THE PAGE ALIGNMENT You will need to set the page alignment the first time you use the adapter. The page alignment synchronizes the timing of the computer with the fax image. The image will appear slanted across the display screen when the page alignment needs to be changed. Once set, the page alignment will not normally need to be changed again. The alignment is set while an image is being received. The procedure is listed below. 1) Begin receiving an image into computer memory. Set fax parameters and select the Acquire fax action. The program will automatically capture the next image into the computer storage. After the adapter has started to display an image, go to step 2. 2) Use the cursor down (down-arrow) key until the page alignment function is selected. If the image slants to the right, use the cursor left (left-arrow) key to decrease the alignment value. Otherwise, use the cursor right (right-arrow) key to increase the alignment value. Continue adjusting until the image appears perfectly vertical. The alignment value is automatically stored in the program file on disk so that the image is perfectly aligned each time you use the program. WeatherFAX User's Guide Page 10 GETTING THE IMAGE 1) SET THE FAX PARAMETERS. o ADAPTER MODE. The fax card can capture three types of weather facsimile images: - Marine Weather Facsimile. These images are received on HF radio on shortwave radio frequencies (e.g., 8080 kHz). The adapter is set to FM mode. The fax adapter allows the FM Marine fax signal to be within a wide amplitude range. However, if the signal output from your receiver is very strong or very weak, you can compensate by adjusting attenuation pads on the adapter. The F4 key allows you to change the pads. Usually, you will keep the attenuation set at NORMAL. This setting allows operation for input-signal amplitudes that vary between -20 dBm to +10 dBm. - WEFAX image. This is the format for geostationary weather satellites. The receiver is usually tuned to S-Band 1691 MHz. The adapter is set to AM mode and Automatic Gain Lock (AGL) is used to automatically set the correct level for any type of image. AGL determines the optimum gain setting at the beginning of every image and fixes the gain level for the duration of the image. This technique provides a distortion free high dynamic range image each time, whether the image capture is started automatically or manually. - Polar image. These are images transmitted from polar orbiting satellites at VHF 137.x MHz. The adapter is set to AM mode and a fixed gain level is used. The F5 key allows you to set the gain of the fax adapter so that the signal level is just right. Use the cursor keys to increase or decrease the signal level while an image is active so that the level covers a wide dynamic range without exceeding the MAX (clipping) value. o SCANS PER MINUTE Selects the number of image lines sampled every minute. Use the same value as that of the signal that you receive. Typically GOES satellites are 240, Polar satellites are 120, and HF fax signals are 120. o PELS PER SCAN LINE Selects the number of samples (pixels) stored for each image line. You would typically set this value to be at least as large as the resolution of your graphics display WeatherFAX User's Guide Page 11 mode (e.g., 640 for EGA or VGA). This sets the resolution of the image and affects the amount of computer storage needed to hold the image. The equation for image size (bytes) is: IMAGE_SIZE = PELS_PER_LINE * NUM_LINES / PELS_PER_BYTE Where: PELS_PER_LINE = pixels stored for each image line NUM_LINES = lines in the image PELS_PER_BYTE = pels stored per byte, either 1 or 2 NOTE: The greater the number of Pels Per Line the greater the image resolution. However the maximum value may be limited by the speed of your computer. For earlier PCs having a 4.77-MHz clock speed use a maximum value of 700 when using 240 Scans Per Minute. The 'squareness' of the displayed image depends upon the Index of Cooperation (IOC) of the received image, the Pels Per Line setting, and the aspect ratio of your display adapter. The relationship for these parameters is: PELS_PER_LINE = π * IOC * ASPECT Where: π = Pi = 3.14 IOC = Index of Cooperation of received signal GOES (WEFAX) = 268 polar satellites = 288 HF fax (Marine) = 576 ASPECT = horizontal/vertical pixel density set by adapter display mode, not the physical size of the display. Extended VGA, VGA = 1.00 EGA (640x350) = 0.73 approximately CGA, MCGA = 0.83 approximately Example: If you want to receive WEFAX (IOC = 268) in VGA display mode for a square picture, use 842 pels per line. o PELS PER BYTE The fax program uses all of the available memory in your computer to capture images. The image size can be calculated by the formula: SIZE = PELS_PER_LINE * NUMBER_OF_LINES / PELS_PER_BYTE PELS_PER_LINE and PELS_PER_BYTE control the image resolution and number of grayshades. If you WeatherFAX User's Guide Page 12 have limited memory (less then 512 kbytes), consider selecting 2 pels per byte. This value saves memory by packing two pixels into each memory storage byte, which allows you to capture images twice as large. The image is stored with 16 gray shades and once captured, you cannot enhance the brightness and contrast. If you have more then 512 kbytes of memory or expanded memory (LIM 4.0), you should select 1 pel per byte. The image is stored with up to 256 shades of gray, and you can enhance the brightness and contrast of the image at any time. 2) SELECT ACQUIRE FAX ACTION. You must have a fax card installed in your computer and your fax receiver must be attached to the card with a cable. The program will automatically capture the next image from the fax receiver into the computer's memory. If the first image appears slanted, the page alignment needs to be adjusted. The bottom line of the display is the action line. It displays the current receive status and allows you to select various actions while receiving the image. Different actions are displayed using the cursor keys. ┌─────────────────────────────────────────────────────┐ │ ACTION LINE SELECTIONS │ │ │ │ Manual start Press <─┘ for manual start │ │ Move/scroll image <- -> keys scroll left/right │ │ Darker - <- -> to adjust brightness │ │ Adj contrast <- -> to adjust contrast │ │ Printer: on/off <─┘ to turn printer on/off │ │ Disk : on/off <─┘ to save to disk on/off │ │ Page alignment <- -> adjust timing. │ └─────────────────────────────────────────────────────┘ Disk allows you to save the image to disk as it is stored in memory. You will be prompted for the filename to use. NOTE: The Disk function has been tested on IBM computers. However, the BIOS of some computer clones disable interrupts when saving to disk; that will cause part of the received image to be lost. When this happens, part of the image will appear shifted. Do not use this function if you have this type of clone computer. Page alignment allows you to adjust the adapter timing if the image is slanted. Once adjusted, the timing should not need to be changed again. Use cursor keys to increase and decrease the timing value. Increase WeatherFAX User's Guide Page 13 if the image slants to the left. Decrease if the image slants to the right. ┌─────────────────────────────────────────┐ │ RECEIVE STATUS │ │ │ │ Wait : Waiting for start signal │ │ Start : Start signal detected │ │ Sampling : Putting image into buffer │ │ End of mem : Image size exceeds buffer │ │ Stop : Stop signal detected │ └─────────────────────────────────────────┘ 3) EXIT ACQUIRE MODE After image is captured, press the Esc key exit to the Fax Acquire Menu. Press Esc again to exit to the Fax Action Menu. From the Fax Action Menu you can view or print the image. VIEWING THE IMAGE You can view an image once it is stored in memory. The image may be either retrieved from disk, or acquired from the fax card. You can then view the image with different display modes, scroll, zoom, and enhance the image details in several ways. DISPLAY MODE You can view the image with different display modes to change the resolution and palette range. Change the display mode using the Setup Menu. Example: VGA mode has high resolution (640 x 480), so most or all of the image may be displayed. However only 16 colors (or grayshades) are viewable at a time. However, by selecting MCGA mode with a lower resolution (320 x 200), small details of interest in the image may be more easily seen. Also with MCGA mode, you can highlight details with 64 grayshades. If you use 50 percent zoom you can see almost the same area as VGA mode but with more grayshades. The cursor keys will allow you to scroll the image up, down, right, and left while in Scroll Mode. Also, you can press the Alt key and either the F1, F2, F3, or F4 keys to select one of the four color look-up tables (LUT). WeatherFAX User's Guide Page 14 ┌───────────────────────────────────────────────┐ │ In Scroll Mode the active keys are: │ │ │ │ cursor keys: scroll up, down, right, left │ │ Home go to top of image │ │ End go to bottom of image │ │ F1 help information │ │ Esc - return from help │ │ - abort when writing screen │ │ - return to last screen │ │ Alt/F1..F4 Select color table │ └───────────────────────────────────────────────┘ If you press the space bar while viewing the image, an action line appears and the mode changes to Action Mode. Use the cursor keys to chose an action, then press the Enter key. The different image enhancement selections are described below. Press the Esc key to return to Scroll Mode. ENHANCEMENT You can change the contrast and brightness using the Enhancement menu if the image was captured with 1 Pel Per Byte. The menu displays a histogram and an adjustment scale which are used as visual aids to help adjust the image brightness and contrast. This changes the display Look Up Table (LUT). The actual image data is not changed. The LUT assigns each of the 256 brightness levels in the image to the limited number of levels displayable by the graphics adapter. The histogram displays a chart of the distribution of brightness values in the displayed image. The horizontal axis displays the brightness level between 0 and 255. The vertical axis displays the number of pixels for each brightness level. The adjustment scale "[ │ ]" indicates both the contrast range and brightness level. The center mark "│" indicates the brightness level. You can make the image darker by moving the "│" to the right using the right arrow key. The "[ ]" marks indicate the contrast range. The contrast is increased by moving the "[ ]" marks closer together. You can use the visual aids for two types of image enhancement: optimize overall picture or; detailed analysis of a particular item of interest. OVERALL PICTURE ADJUSTMENT 1) Use the histogram to locate the right and left edges of the curve where the number of pixels decreases. WeatherFAX User's Guide Page 15 2) Adjust the brightness so that the "│" mark is centered between the edges on the histogram. 3) Adjust the contrast range so that the "[ ]" marks are directly under the right and left edges of the curve respectively. DETAILED ANALYSIS This provides more detailed enhancement of specific areas of the image at the expense of the rest of the image. For example you may want to detail the temperature gradients of the Atlantic Ocean to locate the Gulf Stream. 1) As you adjust the brightness the level corresponding to the "│" mark will briefly flicker or select the corresponding level in the image. Adjust the brightness until you select the area to analyze. 2) Adjust the contrast range so that the "[ ]" marks cover the desired image intensity range. Finding the best contrast range will probably require several trial-and-error adjustments. When you exit the window with the Esc key the display is redrawn with the new Brightness and Contrast values. The values are also used for printing the image. PALETTE You can change the colors and gray scales of the image by changing the look-up tables (LUT) that define the way the image is displayed. With VGA, EGA, and MCGA, 4 tables can be defined. For each table, you can adjust the red, green, and blue colors separately. The table number is displayed at the top of the panel. While the image is displayed you can change to a different tables at any time by pressing the Alt key and either F1, F2, F3, or F4. ZOOM You can select a Zoom of 50, 100, 200 or 400 percent. The 50 percent zoom is useful for shrinking the image to half size to display more of it at one time. The 200 and 400 percent zooms can be used to enlarge the image to better display small details of interest. NEGATIVE IMAGE This displays the negative view of the image similar to a photographic negative. This option is set using the Zoom menu. ROTATE 180 DEGREES. Rotate turns the picture upside down for viewing. This is useful for viewing images from ascending-node (South-to-North track) polar-orbiting satellites that send images upside down. WeatherFAX User's Guide Page 16 PRINTING THE IMAGE Before printing for the first time, use the Setup Menu to select your printer. You can print the image either to a printer connected to your computer's printer port or to DOS device name. The device name could be a file name or the name of a printer attached to a Local Area Network. You can print the entire image or just the part displayed on the screen. The image is printed starting at the top and left side displayed on the screen. This allows you to trim the top and align the left-hand side before printing. You can print the image in black and white, or with a choice of various gray-scale dithering patterns. Dithering is a printing method of using a series of dots in an area to simulate gray information in the same way that a newspaper would via the halftone technique. The dither patterns allow your image to be printed with up to 16 gray shades. Because of the lower resolution of 9-pin dot-matrix printers, you will get good results using either black and white, or 2- and 4-gray-shade dithering patterns. For 24-pin dot-matrix and laser printers, you will get excellent results with all of the dithering patterns including the 16 gray-shade dithers. The 16 gray-shade dithers available are: ┌─────────────────┬────────────────────────────────────┐ │ BAYER │ Brings out detail at the expense │ │ │ of tonal reproduction (contrast).│ │ │ Used for very detailed images. │ │ FATTING │ Good compromise between detail │ │ │ and good tonal reproduction. │ │ VERTICAL LINE │ Emphasizes horizontal lines. │ │ HORIZONTAL LINE │ Emphasizes vertical lines. │ └─────────────────┴────────────────────────────────────┘ Choosing the best dithering pattern for an image is a matter of both experimentation and experience. The Fatting dither offers a good compromise between detail and contrast and is commonly used. The printhead on some printers may overheat when printing large images. If this happens the printer will go into a pause mode to cool down. If the wait is longer than approximately 20 seconds, the program will time-out and quit waiting for the printer to resume. WeatherFAX User's Guide Page 17 If the printhead overheats: - wait for a few minutes for the printer to cool before printing another image. - configure the printer for Unidirectional printing instead of Bidirectional printing. This will slow the printer and allow more time for cooling. - Use the DOS MODE command to prevent the printer time-out condition and to allow the printer to resume printing the image after the printhead has cooled down (e.g.,MODE LPT1:,,P). This DOS command could be placed in the AUTOEXEC.BAT file so that it is executed every time the computer is started. NOTE: If you're using the graphics driver shipped with DOS 4.0 (or later), the 'Shift/Print Screen' keys on the computer keyboard can be used to print a very crude representation of the image. The DOS GRAPHICS.COM driver must first be loaded into memory. The graphics driver shipped with DOS 4.0 supports VGA graphics mode. SAVING THE IMAGE TO DISK You can save either the entire image or just the part displayed on the screen. The image is saved starting at the top and left side displayed on the screen. This allows you to trim the top and align the left hand side before saving to disk. You can save the image using either the standard TIFF (Tag Image File Format) or GIF (Graphics Interchange Format). TIFF has fast file operations and stores an image as an uncompressed raster-scan gray-scale image. GIF is the standard format used for storing images by CompuServe and other computer bulletin boards systems (BBS). GIF is much slower than TIFF, but uses an efficient compression algorithm that minimizes file size and saves disk space. These standard image file formats allow images to be imported as graphics files into various painting and Desktop Publishing applications that support either of the formats. TIFF files are supported by Aldus PageMaker, IBM Image Edit, Logitech PaintShow, and WordPerfect 5.0. Image Edit is excellent for modifying large TIFF image files. GIF format files are used by many computer bulletin board systems (BBS) and are supported by Compuserve CSHOW and several painting programs. WeatherFAX User's Guide Page 18 ADDITIONAL INFORMATION ────────────────────── CALIBRATING THE ADAPTER WeatherFAX card physical layout ┌────▌█──────▌█───────────▌█─────────▌█───────┐ │ ┌─██─┐ ┌─██─┐ ┌─██─┐ ┌─██─┐ │┌─── │ │POT2│ │POT4│ │POT3│ │POT1│ ││ │ └────┘ └────┘ └────┘ └────┘ ││ │ Stop Start AM FM ││ │ Detector Detector Demodulator Demod. █████ <─┐ │ 450 Hz 300 Hz 2400 Hz 1800 Hz █████ phono │ ││ jack │ ││ │ ││ │ ││ │ ││ │ ││ │ ││ └─────────┐ ┌───┘│ └▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌┘ │ Calibration is needed if any of the Self-Tests indicate that the card is operating out of the indicated operating range. The self tests will indicate which parameter is out of range and needs adjustment. Instructions are provided below for making the adjustment. The procedure is simple and can be performed without special tools or knowledge. Because adjustments are made while the computer is powered on it is recommended the adjustment be done by a qualified service technician. A non-metallic screwdriver should be used for the adjustment. This will prevent damage to the computer if the screwdriver should accidentally be dropped into the computer. 1) Turn power to the computer off. 2) Remove the cover of the computer. Refer to the Guide to Operations for your computer for instructions for removing the cover. 3) Locate the fax card. 4) Turn computer power on and start the WeatherFAX program. 5) Select Test Adapter, and then Static Test. Adjust the potentiometers for the parameter out of range. When you are finished all parameters should be in the 'OK' region. WeatherFAX User's Guide Page 19 6) The final adjustment for the FM demodulator should be done while viewing the FM Graph Test. The line should be linear, sloping upward with time, and centered between 0 and 256. If not centered adjust the FM potentiometer while viewing the Graph. USING EXPANDED MEMORY (LIM 4.0) Expanded memory eliminates the problem of acquiring images that are too large for the computer's 640 kbytes of conventional memory. LIM (Lotus Intel Microsoft) 4.0 allows up to 16 Mbytes for image storage. It requires both expanded memory and a LIM 4.0 software driver. The WeatherFAX program will automatically use either conventional or expanded memory based upon the larger available amount of RAM. If you have an 80386 type computer then EXTended memory can emulate LIM 4.0 EXPanded memory by using a device driver shipped with DOS 4.0. The EXTended memory on 80286-type computers cannot emulate EXPanded memory. You must use an actual LIM 4.0 capable memory card. EMS SIMULATORS using either a hard disk or EXTended memory are not supported because of the 'data aliasing' problem that is inherent with simulators. USING EXTENDED VGA (800 X 600 PIXEL) MODE If you have a multifrequency (multisync) monitor and a graphics card that supports the extended 800 X 600 graphics mode, you can display images in this mode. Because different cards use different 800 by 600 modes, you must specify the mode as command line parameter when starting FAX.EXE. To specify the graphics mode: FAX.EXE /Hxx where: 'xx' is the hex mode. Examples: For ATI VGAWONDER the hex mode is 54 -> FAX.EXE /H54 For Paradise Plus the hex mode is 58 -> FAX.EXE /H58 Be sure to check that you have the correct monitor and graphics card. The software does not verify the monitor or graphics card. Selected cards and their respective 800 X 600 graphics mode (hex) are listed below. If your graphics card is not listed, you'll have to consult your card's user's guide to determine the correct mode. WeatherFAX User's Guide Page 20 ┌───────────────────────────────────┬──────┐ │ CARD │ MODE │ ├───────────────────────────────────┼──────┤ │ ATI VGAWONDER │ /H54 │ │ │ │ │ Paradise VGA Plus/Professional │ /H58 │ │ AST VGA Plus │ /H58 │ │ Compaq VGA │ /H58 │ │ Dell VGA │ /H58 │ │ │ │ │ Video7 VRAM/Fastwrite │ /H62 │ │ │ │ │ Genoa Super VGA/VGA Hi-Res │ /H29 │ │ Orchard Designer VGA │ /H29 │ │ Sigma VGA/H │ /H29 │ │ STB VGA Extra │ /H29 │ │ │ │ │ Everex EVGA │ /H70 │ │ │ │ │ Tecmar VGA-AD │ /H18 │ └───────────────────────────────────┴──────┘ NOTE: You may need to adjust your multisync monitor to display the 800 X 600 graphics mode properly. Use the vertical and horizontal size and position controls on your monitor to display the entire image without distortion. SOURCES OF WEATHER-FACSIMILE SIGNALS There are three direct sources for weather-fax signals: geostationary satellites; polar-orbiting satellites; and Marine weather-radio transmitters. The fax card along with the WeatherFAX software can capture all the above types of facsimile. Tone detectors on the card will automatically detect the beginning and ending of each image. Geostationary Satellites. Geostationary satellites include US GOES, European Space Agency METEOSAT, and Japanese GMS. These spacecraft broadcast on S-Band frequencies; GOES at 1691 MHz and Meteosat at 1694.5 MHz. These satellites are located approximately 22,000 miles above the Earth and provide WEFAX (Weather Facsimile) transmissions using the standard Automatic Picture Transmission (APT) format. Reception of WEFAX images require an antenna, downconverter, and receiver The antenna can be either a small parabolic dish or a loop Yagi. The downconverter converts the S-Band signal to 137.5 MHz. An inexpensive scanner radio may be used for the receiver. A phone cable from the receiver plugs into the WeatherFAX card. WeatherFAX User's Guide Page 21 Configure the software for AM mode and 240 scans per minute. Polar-Orbiting Satellites. These satellites transmit on VHF frequencies between 137 and 139 MHz. The NOAA (TIROS-N) series transmit at 137.50 MHz and 137.62 MHz. The Russian Meteor series satellites transmit at 137.15, 137.3 and 137.850 MHz. A general-purpose scanner receiver capable of receiving the frequencies between 136-138 MHz is required. Many of the newer Regency, Uniden, and Radio Shack scanners cover this frequency range and give excellent results. This receiver can also be used in conjunction with the geostationary satellite antenna and downconverter. Configure the software for AM mode and 120 scans per minute. Marine weather radio facsimile. These broadcasts can be received direct from government radio transmissions. There are over 65 transmitter sites worldwide which utilize over 200 different radio frequencies. The information transmitted includes weather-analysis charts, satellite pictures, and radar charts. These radio signals are received on short wave radio frequencies (e.g., 8080 kHz) on Upper Sideband. A stable general coverage single sideband (SSB) receiver is required. The published frequency is normally the center frequency of the upper sideband. Tune your SSB receiver approximately 1600-1700 Hz below the published frequency. For example, the US Navy Fleet Weather Station at Norfolk (NAM), transmits at 8080 kHz. Tune your receiver to 8078.3 kHz (USB) to receive its transmissions. Configure the software for FM mode and 120 scans per minute. DECODING RTTY Many weather radiofacsimile transmitters broadcast radioteletype messages in addition to charts and images. These are primarily coded surface and upper air reports from around the world. - Surface Reports contain temperature, dew point, wind speed and direction, altimeter, present weather, past weather, 6-hour precipitation amounts, cloud coverage, snow accumulation, high and low temperature, and occasional text information. - Upper Air Reports contain temperature, dew point, wind speed and direction at standard and variable levels of the atmosphere. These RTTY messages are usually transmitted at 100 WPM with normal sense and 850-Hz wide shift. WeatherFAX allows you to receive these RTTY broadcasts with standard Baudot speeds from 60 to 133 words per minute. A stable, general-coverage, single sideband WeatherFAX User's Guide Page 22 (SSB) receiver is required. You can select normal or reverse sense. Reception is in FM mode. You can send the RTTY messages to your printer or a disk file. NOTE: This product is not suitable for general-purpose Amateur radio RTTY decoding. It has limited performance in noisy environments and with narrow shifts. It is primarily intended to decode RTTY from HF fax stations that broadcast both RTTY and fax. WEATHERFAX SPECIFICATIONS o Recording Rate : 60, 90, 120, 240 SPM (Scans Per Minute) o Index of cooperation IOC 576 - Marine fax 288 - TIROS 267 - WEFAX (GOES) o FSK input : 1500 Hz "black", 2300 Hz "white" o FSK input level : Range selectable by pads. -10 dBm to +20 dBm Strong Signal -20 dBm to +10 dBm Normal Signal -30 dBm to 0 dBm Weak Signal o AM input : 2400 Hz AM modulation lower voltage = "black" higher voltage = "white" o AM input level : -20 dBm to +10 dBm. o Input impedance: 10 kilohms o Control signals Automatic start, frame, and stop with manual start and frame. - START : Signal modulated between "black" and "white" at 300 Hz rate for 5 seconds. - STOP : Signal modulated between "black" and "white" at a 450 Hz rate for 5 seconds. - FRAME : "black" signal interrupted by a short burst at a "white" signal each scan line for 5 seconds immediately following start signal. o Hardware interrupt 8 (BIOS timer interrupt) o I/O Addresses 386H and 387H WeatherFAX User's Guide Page 23 o Voltage & current requirements ┌─────────┬─────────┐ │ Voltage │ Current │ ├─────────┼─────────┤ │ + 5V │ 120 ma │ │ +12V │ 25 ma │ │ -12V │ 15 ma │ └─────────┴─────────┘ IF YOU HAVE DIFFICULTY ────────────────────── SYMPTOM SOLUTION ───────────── ──────────────────────────────────────── NO PICTURE 1) Run fax card tests to assure that the card is operating within the correct range. 2) Verify that Adapter Mode is set correctly for the facsimile signal. 3) For Marine fax mode verify that the receiver signal level is within the range of the fax card attenuation pads. If the signal level is very weak then decrease the attenuation pads using the F4 key on the adapter mode menu. 4) Is the fax receiver powered on and the cable connected to the fax adapter? DISTORTED 1) Verify that the Adapter Mode is set PICTURE correctly for the received signal. (e.g., if the image is WEFAX then the Adapter Mode must be set to AM. 2) Verify that Scans per minute is set correctly for the received signal. 3) If the image is slanted then the Page Alignment needs to be adjusted while an image is received. 4) For FM Marine fax verify that the receiver is tuned correctly. Marine fax images are usually transmitted using Upper Side Band (USB). The receiver must be tuned approximately 1700 Hz lower then the center frequency. Example: For a 8080 KHz HF fax signal, the receiver should be tuned to 8078.3 KHz. (8080 kHz - 1.7 kHz = 8078.3 kHz). Vary the receiver frequency slightly to get the best picture. 5) Check to see if any TSR (terminate and stay resident) programs are in memory. If they are, remove them. Some TSR WeatherFAX User's Guide Page 24 programs may cause problems when running WeatherFAX. EXPANDED Be sure that the Expanded memory MEMORY NOT device driver (LIM 4.0) is loaded RECOGNIZED: into memory. If you have an 80386 type computer, then the EXTended memory can emulate LIM 4.0 EXPanded memory using a device driver shipped with DOS 4.0. For 80286 computers, EXTended memory cannot emulate EXPanded memory. 800 x 600 1) Verify your graphics card supports this DISPLAY mode. DOESN'T 2) Verify that you have a multifrequency WORK monitor that supports 800 x 600 resolution. 3) Verify you have set the correct BIOS display mode. 4) Verify that the correct mode is listed as a command line parameter. ADAPTER/SOFTWARE AVAILABILITY ───────────────────────────── The WeatherFAX adapter and software are available from: OFS Software 6404 Lakerest Ct. Raleigh, N.C. 27612 o Assembled and tested scan-converter board, software and instructions ......................$360. o Kit including PC board, all parts, software and assembly instructions .............$230. o Software only See section "General Information" for copyright information and suggested contribution. Terms: - Specify either 5.25" or 3.5" diskette format for the software. - North Carolina residents add 5% sales tax. - Please add $6.50 for shipping and handling. (or add $12.00 for overseas orders.) - Check drawn on a US bank in US funds. International bank or postal money order in US funds. All foreign orders must be prepaid. - Please allow 4-6 weeks for US delivery. WeatherFAX User's Guide Page 25 TRADEMARKS USED IN THIS GUIDE ───────────────────────────── o GIF and Graphics Interchange Format are trademarks of Compuserve Incorporated o Turbo C is a trademark of Borland International o IBM and PS/2 are trademarks of International Business Machines Corporation o PageMaker and Aldus are registered trademarks of Aldus Corporation. o Apple, ImageWriter are registered trademarks of Apple Computer Inc. o LaserJet is a trademark of Hewlett-Packard Company. o Intel is a trademark of Intel Corporation. o Microsoft, and MS-DOS are registered trademarks of Microsoft Corporation. o WordPerfect is a trademark of WordPerfect Corporation.