How to Receive Weather Pictures from NOAA Satellites

So you have decided you want to receive the NOAA and Russian METEOR orbiters and you have a radio that receives 137.500 MHz and a computer. So now what do you do? I hope this short dissertation will steer you in the correct direction.

To display a picture from the orbiting birds you need several things. First you need to 'acquire' the satellite. This means you need the program to calculate its position at any time and determine if you can hear the signals from the 'bird'. The best place to get this program is probably AMSAT-NA an organization dedicated to AMateur SATellites. They have several very good tracking programs for the IBM and also for Commodore and Apple as well. After you have acquired the program and have it running on your computer, you then need the Keplerian Elements for the NOAA satellites. These elements as well as some tracking programs are available from the CELESTIAL RCP/M, run by TS Kelso, at 513-427-0674 (Fairborn,OH) and from the Weather Fax and Remote Imaging DATALINK BBS run by Dr. Jeff Wallach, N5ITU as bulletins for some 100+ sets of satellite data. Another bulletin also tells you to what the printed numbers correspond so you can enter them into the computer program. Use the newest elements you can find as the orbiting satellites are subject to forces which change their orbits. If you use Keplerian Elements more than 3 or 4 weeks old, your chances of hearing the bird are reduced.

Once you are tracking the birds you should hear them on your receiver. They will be on 137.62(NOAA-9/11), 137.500(NOAA-10), and on 137.850, 137.400, and 137.300 for Soviet Meteorlogical Satellites / METEOR. Now comes the first thing different about NOAA orbiters. The frequency deviation of the FM transmission is about +/-18-20 kHz. This is 4 times the normal deviation of a police call and 1/3 the deviation of the FM broadcast band FM signal. If you receive the signal on the regular communications width of the scanner the light areas of the picture will be noisy and the signal will sound distorted and the picture will basically be useless. If you use the FM broadcast bandwidth (assuming your scanner will let you), the signal will be weak and there may be too much background noise to see the picture.

So what now ? Well there are two ways to fix the problem, find a receiver with the proper I.F. bandwidth filter of 50 kHz, or modify the I.F. of your scanner to about 50-80 kHz. The simplest mod which has been found to be workable is to remove the narrow communications I.F. filter and replace it with a 0.01 uFd capacitor. This provides for good Wefax pictures from GOES and pretty fair NOAA orbiter pictures. It can of course result in retuning the radio, voiding the warranty and making the squelch not work properly.

The other characteristic of the NOAA satellite transmissions is THEY ARE WEAK. To get good pictures over a large area we have found a pre-amplifier to be essential. A GaAs-FET type can be obtained from various sources at a reasonable price but still about 50-100 dollars. You can also build one for about 25 dollars from plans for a pre-amp for the 2-meter amateur band and tune it to 137.5 easily.

Lastly, but importantly, the antenna can be of an omni directional, uniform pattern type such as a turnstile antenna similar to those used in the FM broadcast reception business but of course tuned to 137.5 MHz. Mount the pre-amp at the antenna if possible. Crooked coathangers on broomsticks have been known to work, and it is not difficult to build the antenna. Of course 2-meter beams with Az/El tracking will do the job well.

Now that you have a nice audio signal from the satellite, what happens next? The audio tone of 2400 HZ which is the carrier tone that is used to carry the picture information (video), must be detected and the video data converted from analog to digital and then displayed on the computer monitor by the software. The hardware and software to do this is available from several sources with more coming along. Several stand-alone boxes are also available that produce some form of computer output either in printed form or on the display. In addition the people on the DATALINK BBS may also have some data to share with you regarding this equipment.

One of the best sources for information is the WEATHER SATELLITE HANDBOOK by Dr. Ralph Taggart. The 4th edition will be available from the ARRL later this year. A must is THE JOURNAL OF THE ENVIRONMENTAL SALELLITE AMATEUR USERS' GROUP - JESAUG - which is published quarterly. It is available for $30.00 per year from the editor, Jeff Wallach, PO Box 117088 Carrollton, TX. 75011-7088. Back issues of the JESAUG are also available.

One good place to start is with the Elmer Schweittek MULTIFAX software which runs on the IBM PC. A hardware kit is available from A&A Engineering which includes the video dectector circuit and A/D converter. Input to the PC is via the game port. If you want to build your own, complete documentation to build an interface circuit on an IBM PC prototyping board is available from H. Paul Shuch, N6TX, for $6.00 - FAXBOARD is also described in QEX, Sep `88.

The units available from Jim MacLean, Ralph Taggart, and Jerry Dahl listed under Sources are all well worth investigating if you are just getting started. DATALINK will have available by early summer an APT interface card for the IBM PC that can be built for less than $100.

NOAA Data / Keplerian Elements

DATALINK RBBS, N5ITU, Dr. Jeff Wallach, 214-394-7438, DALLAS REMOTE IMAGING GROUP ELECTRONIC BULLETIN BOARD UPDATES ON NOAA BULLETINS, SATELLITE LAUNCHES, FREQUENCIES DISPLAY PICTURES FROM NOAA SATELLITES ON YOUR OWN P.C.

CELESTIAL RCP/M, TS Kelso, 513-427-0674, NASA Prediction Bulletins are online and updated several times weekly

Satellite Tracking Software

AMSAT-NA, PO Box 27, Washington, DC 20044, Software Exchange, phone 301-589-6062 (voice), N4HY - QUIKTRAK, W0SL - ORBITS II,III,IV, and InstantTrack by Franklin Antonio.

Roy D. Welch, W0SL, 908 Dutch Mill Drive, Manchester, MO 63011, phone 314-391-1127, ORBITS II-CGA, ORBITS III-EGA, ORBITS IV-VGA DATALINK BBS, download SATTRAKx.ARC, SEESATxx.ARC, TRACKSAT.xxx and others CELESTIAL RCP/M, TS Kelso, 513-427-0674, SATTRAKx.ARC or SEESATxx.ARC

Astronomical Data Service, Rodger Mansfield, 3922 Leisure Lane, Colorado Springs, CO 80917-SPACE BIRDS program and Newsletter, $40.

Receivers

Vanguard Labs, 196-23 Jamaica, Hollis, NY 11423, phone 718-468-2720, BBS Dataline 718-740-3911

Hamtroincs, Inc.,65-D Moul Road, Hilton, NY 14468-9535 phone 716-392-9430

DARTCOMM, Mr. N. Hearn, DARTCOMM Ferndale, Postbridge, Yelverton, Devon PL20 6SY, Great Britain, UK, phone 011 44 0822 88253

Quorum Communications, PO Box 277, Grapevine, TX 76051, phone 817-488-4861, BBS Dataline 817-464-7284

Crystals

JAN Crystals, 2400 Crystal Dr, Fort Myers, FL 33906-6017, phone 1-800-237-3063 or 813-936-2397

Pre-Amps

Quorum Communications, PO Box 277, Grapevine,TX 76051

Spectrum International,Inc., Box 1084, Concord MA 01742, phone 617-263-2145

Vanguard Labs, Hamtronics and GLB for Helical RF Filters for intermod Ehrler-DuBois Very High Performance LNA for 1500-1750 Mhz, contact Greg Ehrler or John DuBois via DATALINK

Antennas

ARRL Handbook, 1986, turnstile over ground antenna.

ARRL Satellite Experimenter's Handbook by Martin Davidoff, K2UBC

Modern Electronics, September 1988, Hank Brandli article, page 82, Receiving Satellite Weather Photos

Hardware Interface to PC

A&A Engineering, 2521 W. La Palma, Unit K, Anaheim, CA 92801, phone 714-952-2114 - both AM dectector and A/D converter, input to PC via game port (4-bits) or parallel I/O Interface (8-bits) - kit is $50. - assembled and tested unit is $70.

Microcomm, H. Paul Shuch, N6TX, 14908 Sandy Lane, San Jose, CA 95124, phone 408-377-6137 - FAXBOARD - A Weather Facsimile Display Board for the IBM PC - Complete documentation to build your own interface circuit on an IBM PC prototyping board - video and an 8-bit A/D interface - $6.00, also in QEX, Sep '88.

Video Detectors

RTM Circuit Boards, 205 Elm St.,Van Horne, IA 52346-0400, video detector (the 'Wilson Board') see QST Magazine, Jan '86 and Vince Coppola's article in Oct 1988 73 Magazine

QST Magazine, August 1985, Grant Zehr article, page 27, video detector circuit

A/D Converter & Parallel I/O Interfaces for the IBM PC:

MetraByte, 440 Myles Standish Blvd., Taunton, MA 02780, Model PIO-12 board for the IBM PC, phone 617-880-3000

John Bell Engineering, Inc, 400 Oxford Way, Beimont, CA 94002, phone 415-592-8411

Display Software and Hardware - 'Amateur'

Multifax, Elmer Schwittek, 2347 Coach House Lane,Naples, FL 33942, phone 813-434-2268 - Multifax 4.x for VGA, 3.x for EGA on the IBM-PC

Clay Abrams Software, 1758 Comstock Lane, San Jose, CA 95124, software for the ROBOT 1200 - see QST Magazine, Jan '86

Ralph Taggart, 602 S. Jefferson, Mason, MI 48854, Weather Satellite Handbook Scan Converter - New Model 1700 APT Scan Converter for the the IBM PC. Order Handbook from the ARRL, Scan Converter from Metsat Products, 1257 Glen Meadows Ln, East Lansing MI, 48823, phone 517-332-7665. Also see 73 Magazine, Nov '84 and Dec '84, WSH/Handbook, and WEATHERSAT columns in 73 Magazine from 1987 and 1988.

ImageWise Display/Receiver, Circuit Cellar Inc. - Micromint Inc., 4 Park Street, Vernon, CT 06066, phone 203-875-2751 - BYTE Magazine, May, Jun, Jul, Aug 1987. JESAUG 88-2 and Oct 1988 73 Magazine have information on how to build the video and A/D interface. Ver 2.0 software supports VGA graphics and 640 samples per line at 64 gray levels. With VGA the ImageWise Display unit is not required. The software is available for $29.95 from Vince Coppola, N1VC, 6 Bobbin Road, Terryville, CT 06786

ASAT: An Apple-based Satellite Imaging System by Grant Zehr, WA9TFB - QEX Magazine, March '88 - has complete information to build an excellent unit using the APPLE with a Redshift Ltd graphics card giving 256 * 256 pixels at a full 256 levels of gray.

AMIGA Imaging Software - Dallas Remote Imaging Group, PO Box 117088, Carrollton, TX 75011-7088, Voice 214 394 7325. Uses standard Amiga hardware - no special display. Powerful NASA digital enhancement curves built-in. Digital image processing capabilities. Uses A&A Engineering $49 demodulator. Image saved for use by other graphics programs. Full histogram analysis. Full 8 bit data is stored on diskette or hard disk. Unattended operation. Can be setup in 30 minutes. Call for special pricing.

IBM-PC Interface Card and Software - Jim MacLean and Paul Atkinson, 2112 Parsons Avenue, Melbourne, FL 32901, 407-727-3646 - plug in card for IBM XT or AT, 9600 samples/second at 8 bits, automatic synchroniztion for NOAA, METEOR and WEFAX, data saved realtime to hard disk, supports CGA, EGA, and VGA, $300 for hardware and software A Weather-Facsimile Package for the IBM PC by Jerry Dahl in April and May '90 QST describes how to construct a complete FAX system. Notes at the end of artilce contain an excellent list of hardware and software sources

Complete Systems - Hardware and Software

YU3UMV Digital Storage and Scan Converter for Weather Satellite Images, described in VHF Communications Magazine, Winter 4/82 and Spring 1/83 - Modifications are described in the Satellite Users' Group Journal - JESAUG - available from Jeff Wallach. Back issues of VHF Communicatons and the YU3UMV printed circuit boards are available from Fred Sharp, TimeKit, P.O. Box 22277, Cleveland, OH 44122, phone 216-464-3820.

Loren Johnson, P.O. Box 219, Cleveland, MN 56017, system for the IBM-PC - $750, phone 507-931-4849

WEATHERTRAC[tm] IBM-PC Based Satellite Image Acquisition and Animation System - $1885 for EGA - $3495 for VGA, Fred Bartlett, Softworks, Inc, Allentown, PA, phone 215-395-4441 or George Isleib, Lehighton, PA, phone 717-386-4032

Quorum Communications, PO Box 277, Grapevine, TX 76051, phone 817-488-4861, BBS Dataline 817-464-7284, offers a fully integrated system for the IBM PC including GOES down converter, GOES/APT receiver, Wefax PC Adapter and software. A demo disk is available on request or via the Quorum BBS.

Satellite Meteorology

Satellite Imagery Interpretation for Forcasters - a 3 volume set published in 1985 for NOAA now available from the National Weather Association, 4400 Stamp Road, Room 404, Temple Hills, MD 20748, 301-899-3784, $32 for members, $45 for non-members ( Membership is $20. )

Bibliography - Online DATALINK Bulletins (214 394 7438 -- BBS)

NASA Satellite Prediction Bulletins, NASA-PB.xxx

How to use NASA 2-Line Keplerian Elements

AMSAT Bulletins and Weekly Notes / Orbital Elements

NOAA APT NOTES

NOAA User Bibliography

Summary of Soviet Meteorological Satellites by Grant Zehr

How to Build a Weather Satellite Groundstation (This Primer)

Wrasse Dedicated System Review

GOES VAS Imaging System for the IBM PC, John DuBois W1HDX

LNA for WEFAX-VAS-HRPT-GPS, John Dubois and Greg Ehrler

GOES I-M Converence Summary

Ralph Taggart's New APT Scan Converter and Book

Dartcom 137-138 Synthesized Receiver Packaging, John DuBois

Amateur Radio News from Newsline, Bill Pasternack

How to VISUALLY OBSERVE the Space Shuttle, Ted Molczan

AMSAT InstantTrack V1.00 program description, Franklin Antonio