----- Original Message ----- From: Bob Ammerman <RAMMERMAN@PRODIGY.NET> To: <PICLIST@MITVMA.MIT.EDU> Sent: Thursday, October 19, 2000 4:22 PM Subject: Re: [OT]: Long range position feedback anyone ? > No need to point the antenna: point the boat! > > Radio is not my specialty, but... > > Transmit on a known schedule. > > Transmit highly redundant data. > > Look at some of the techniques used to pull usable signals out of the noise > on deep space probes. > > I would expect that a few watts would get you where you need to go. Oh, and since you know where the boat last was, and it probably hasn't gone far since then: A high directional, high gain, antenna on your receiver. > > Bob Ammerman > RAm Systems > (contract development of high performance, high function, low-level > software) > > ----- Original Message ----- > From: M. Adam Davis <adavis@UBASICS.COM> > To: <PICLIST@MITVMA.MIT.EDU> > Sent: Thursday, October 19, 2000 4:04 PM > Subject: Re: [OT]: Long range position feedback anyone ? > > > > As this is quite an ambitious project, I would suggest two things: > > > > Invite people from the ham groups to participate > > Invite corporations to participate and donate > > > > While this would involve your time and energy, your returns would be > greater > > than what you put into your efforts in these two areas. > > > > In order to have a long distance transmission, you go as low in frequency > as you > > can (given antenna limitations), and you get as highly sensitive of a > receiver > > as you can. > > > > If you want to increase project complexity, you can also get and use a > compass > > module to give you the direction you are currently pointing in. Have an > array > > of antennas which are set up to cover 60 to 90 degrees, and use only one > > antenna, pointing towards the USA, or the two antennas pointing east and > west. > > This would give you a longer distance transmission. > > > > -Adam > > > > Tobie Horswill wrote: > > > > > > Hi, > > > > > > I know close to nothing regarding wireless transmission such as > radio, > > > packet, satellite and the like but I was wondering if there would be an > > > economic way for an autonomous vehicle to send it's position back home ? > The > > > vehicle is a solar powered boat already equipped with a GPS receiver > used > > > for navigation and it would be a piece of cake to add a daily routine to > the > > > PIC for uploading this information to some RF stage. Here is the catch : > the > > > boat can be anywhere in the middle of the Atlantic ocean and obviously > has > > > very little power available (in fact barely enough to keep it moving). > The > > > boat could stop while it transmits to save power and wait for it's > batteries > > > to recharge before going on, that's not a problem. The required > bandwidth is > > > minimal and only a few bytes would be sent daily. The received data > would be > > > used to update the boat's daily position on a Web site. At this point, > I'm > > > only looking for one-way transmission, nothing would get sent back to > the > > > boat even though that would be cool ... > > > > > > I was thinking of something like the transmiters they put in Tuna > fish > > > to track their migration habits. Any idea who makes these things and how > > > they work ? Is direct ground to ground transmission possible accross the > > > Atlantic with such little power available ? Is satellite the only way to > go > > > ? > > > > > > Thanks, > > > > > > Tobie Horswill > > > Ex Machina, Quibec (Quibec) CAN > > > thorswil@hotmail.com > > > > > > -- > > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > > "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other > "[BUY]:","[AD]:" =Ads > > > > -- > > http://www.piclist.com hint: PICList Posts must start with ONE topic: > > "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other > "[BUY]:","[AD]:" =Ads > > > > > > > > > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other "[BUY]:","[AD]:" =Ads > > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other "[BUY]:","[AD]:" =Ads