METEOR.TXT ver 8.0 APRS METEOR SCATTER revised 16 Nov 99 Bob Bruninga WB4APR revised 10 Sep 07 Revised 20 Dec 2007 to promote an APRS emergency Email system Meteors constantly bombard the atmosphere leaving numerous ionized trails. Athough individual trails are random, there is a long term continuum to provide almost continuous data throughput of around 2 words per second average over ranges of 500 to 1000 miles. This is usually done by two stations operating full duplex on separate frequencies with beam antennas pointing to the same area of the sky, and running the highest practical power levels (100% transmit duty cycle). The optimum frequency seems to be around 40 MHz, making the 10 meter and 6 meter bands the most favorable. Usually data is transmitted at high data rates 4800 or 9600 baud so that the packet lengths are very short. On average a few get through every few minutes. Can Meteor scatter work on 2 meters? Yes and no. K1HTV and W0RPK completed the first packet QSO between Maryland and Iowa during a meteor shower back in 1984. Running very high power, and it still took 2.5 hours to complete the contact. My APRS station has been on the APRS 2 meter frequency 24 hours a day for 6 years, along with hundreds of other stations across the country. In all that time I have seen only two random packets that could be attributed to Meteor reflection during meteor showers. This is due to using an OMNI antenna and the constant QRM on the channel. But if you use a beam, then your station can hear many meteor packets if you can just find a quiet location to listen. Point your beam towards a high density APRS location about 500 to 1000 miles distant. THen get some sleep and see what you capture by the next morning. WIth the New-N paradigm in most APRS digis across America, there is much less QRM and so it is easier to hear some silent periods when such packets might get through. METEOR SHOWERS: Even better is to get your local SYSOP to participate during the three or four major meteor shower events every year by disabling WIDEn-N digipeating (UITRACE OFF) and enabling the UIDIGI ALIAS LIST with WIDE1-1,WIDE2-2,WIDE3-3,WIDE2-1. This way the digi still fully supports all local activity while ignoring out-of-area packets that would interfer with meteor packet monitoring. APRS EMERGENCY EMAIL SYSTEM 6 meters 51.63 MHz: In response to the Katrina type disaster, and recognizing the one-hand- clapping advantage of APRS at autonomously receiving and forwarding Email into the global APRS system, we propose that as many IGates as possible be connected to 6 meter receivers monitoring the 51.63 MHz frequency 24/7. Then if anyone, anywhere in the USA finds themselves as a first responder with no connectiivty, they can come up on 6 meters with 100 watts and beacon out as many one line emails as they can load up into a 1200 baud TNC. The APRS system will blindly receive them, eliminate all dupes and send those emails to the intended recepients without needing operators at the receive sites! SImillarly, inbound traffic can be beamed into the area for receipt. We propose two meters using XXXXXX for the inbound leg and 9600 baud. This is beacuse any TM-D700 or D700 can be used for 9600 baud receipt, and 9600 baud will have higher probabilty of success. ------------------------------------------------------------------------ PREVIOUS RESULTS (1995): HOWEVER, using APRS during the 1995 Persieds, 18 stations with beams saw packets over 1000 mile paths on the same National APRS chanel of 145.79. BUT in 1998, The national APRS frequency was changed to 144.39, leaving 145.79 free for a year or so for MS experments until 145.800 began to be used by the crew on the ISS. In 1999, it was suggested to try 147.585 MHz. There are TWO things we can to with APRS and METEOR SCATTER. The first is to play with it on 2 meters during the very predictable Meteor SHOWERS that happen a few times a year. The second is to begin building a 6 meter MS network for emergency email reception from a disaster area. APRS is an ideal tool for generating valuable but SHORT packets and for displaying and recording them. METEOR SHOWER EVENTS ON TWO METERS: APRSdos has a MS mode to improve the probabilities of seeing APRS packets during a Meteor Shower (MS). Unfortunately with changes going on in the APRS Specification, there are now many versions and many ways to do this, and some are not compatible. SO TEST your APRS to see what works for you: Prior to APRS version 840, APRSdos used a "GRID-IN-TOCALL" format: W3XYZ>FM19DX:]$[comment^HP... | || | |*- - P= SqrRoot(P/10): 2=40, 3=90, 5=250, 9=910 | * - - H= heading /10: 2=20, 9=90, A=100, Z=350 * - - - - - - - ]$[ indicates that the TO address is the grid square and the $ is the map symbol W3XYZ>APRS:[FM19DX] is an older format that will also work Then we introduced a new GRID-IN-STATUS format that would be compatible with the thousands of Kenwood THD7 radios which could not receive either of the above formats. THis is the current; recommendation, but it is not yet supported by any other program but APRSdos. BUT. ALL OTHER PROGRAMS will still capture the packet as a STATUS packet. YOu can then plot them later... W3XYZ>APRS:>FM19DX/$ Comments...^HP (Here the /$ is the APRS TABLE/Symbol) Whatever the format, APRSdos in MS mode performs the following additional changes to normal operation: 1) Sets your STATUS/POSIT to the above format 2) your digipeater path is removed 4) CONTROLS-FILTER-LIMIT is enabled to ignore all but DIRECT packets 5) CONTROLS-OTHER is set to capture OTHER packets 6) The country is divided into four regions and everyone in each region transmits randomly on the same 15 second sycle. This significantly improves the chances that stations 500 to 1000 miles away will be LISTENING when a DX packet is being transmitted. 7) When your station transmits, it will send from 10 to 20 copies of your packet (.25 secs each, or about 3 seconds total). Or a full 15 seconds of packets if you choose 100%. 8) Your TNC is placed in FULL DUPLEX mode so multiple local TNC's will transmit at the same time, instead of collision avoidance. 9) The objective is to see POSITS and record HEARD logs. There is NO enhancement given to other APRS packets (ie, messages). In order for this to work optimally, everyone must be synchronized to within a few seconds of WWV! APRS will let the Northeast transmit from 00 to 15, then the Southeast to 30, then the Southwest to 45 and then the Northwest to 00. The dividing lines are 39 degrees latitude and 96 degrees longitude. Most Meteor showers only peak for a few days, so, although this mode will generate a LOT of local QRM on 145.79, it wont last long! TWO WAY CONTACTS: Two-ways are really only expected on 6 meters, but here is the procedure suggested by W0RPK and implemented in APRSdos: 1) When you see a MS packet from another station, use the INPUT-STATUS command to enter an Snn signal report. Send Snn/HISCALL where nn is the number of packets copied from that station. 2) WHen you see an Snn report from another station, send back his report with an R on the end: SnnR/HISCALL 3) WHen you see an SnnR from another station, send back SnnR73/HISCALL 4) WHen you see SnnR73 from the other station, then you have one for the record books. In all of these exchanges, the number nn will probably increment as the number of successfull packets accumulate. In MScat mode, APRS always keeps the GridSquare in the TO call, so you have to communicate via the comment field in the format above. DURING A METEOR SHOWER PLEASE DO THE FOLLOWING: 1) Set UNPROTO PATH TO NONE, nothing, nadda, zip, zero 2) Use MAXIMUM POWER and coordinate your BEAM headings not to overlap the beam headings of other transmitting stations in your area 3) Check your screen daily for MS posits. Especially in the morning. Look at the APRSdos D-LIST to be sure it was heard direct. 4) Look on the MAP, POSIT-LIST, LIST-STATUS and HEARD pages for contacts. BUILDING A METEOR SCATTER NETWORK ON 6 METERS: To make this work, ideally we need to operate at 100 watts or more, and use 9600 baud packets. But with the price of the Kantronics KPC-9612+ TNC now above $300, and since the 9600 baud TNC's built into the Kenwood D7 and D700 do not operate on 6 meters, we probably should consider using 1200 baud to be compatible with more availaable hardware out there. 1) It is easy to find 100W surplus highway-patrol radios for about $50 2) The Kantronics 9612 TNC has both the 1200 and 9600 baud modems that can operate on both 144.39 for normal APRS, and 9600 baud on 6m for MScat. Transmitting normal APRS packets at the normal timings, however, will almost certainly not be seen. 3) The best way to transmit is by placing the outgoing emergency message into the TNC's BText and setting the beacon rate as high as possible. On 6 meters, the objective of the network is to receive any MS packets and inject them into the APRS Internet System. Remember that MS is MORE reliable than the ionosphere and HF. It will be a good band for getting out emergency emails and for reporting the position of distant mobiles (who can afford to run 100W on a 20% or so duty cycle!) THINGS TO DO! We need to get a NATIONWIDE 6 meter APRS Meteor Scatter frequency AND A SEPARATE 2 meter meter Meteor Scatter return frequency. The 6 meter frequency is monitored 24/7 by as many IGates as we can muster. The 2m frequency is only used during an emergency to try to get short messages back INTO the affected area for receipt on any D& or D700 mobile. Here was the 1995 band plan in the Washington DC/Baltimore area: 50.62 Packet backbone (defunct) XTALS in hand tho! GOOD MS freq!? 50.64 50.66 50.68 50.70 OLD RTTY FREQ 50.72 50.74 50.76 50.78 SUGGESTED APRS FREQ? 50.80 Lower band edge for remote control Problem is that there was a NETROM node system on 50.625 MHz that objected strongly to use of that frequency some time ago. ANd the ARRL plan tended to center the channels on the odd 10 KHz slices, suggesting 50.63. That frequency 50.63 was xtaled up in many early PROPNET experiments, though no longer used. 1999 Update. Apparently 53.53 is now the preference of APRS 6m operators. This is still confirmed in 2007. Enjoy! de WB4APR, Bob