Re: [amsat-bb] tracking programs: azimuth output
Standard azimuth reporting is relative to True North. On Sat, 2014-07-26 at 10:58 -0400, Lizeth Norman wrote: Hi all! Stupid question but one that has been bothering me. What reference does satpc32 and Orbitron use to generate the azimuth? Is the resulting heading true or magnetic? Comparing the two programs, they seem to be the same. Norm n3ykf ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: International Designators
It shouldn't disrupt systems. The specification for the international designator allows for one to three (3) suffix characters (i.e., A through ZZZ). 73, Ken N2WWD Sent from my iPad On Nov 13, 2013, at 5:44 AM, Graham Shirville g.shirvi...@btinternet.com wrote: Hi All, At least one of the forthcoming launches is planning to having more than 26 objects being deployed. I think this is the first time that this has occurred. Our TLEs include these references. I understand that after Z is used, the sequence will be AA, AB, AC, AD, etc. Question - will this extra digit disrupt the existing systems we have for distribution of this data or when importing the files into the various prediction programmes that we all use? I may be worrying unnecessarily but ..just in case! thanks Graham G3VZV ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: satellite los footprints
Joe - I did the implementation described in a professional flight dynamics software program. The convention (as specified by the gov't) is to have an array of 360 azimuthal obscura elevations. The first entry defines the minimum elevation for 0 to 1 deg in azimuth, the second entry defines the minimum elevation for 1 to 2 deg in azimuth, up to the 360th entry defining 359 to 0/360 deg in azimuth. The 1-deg wide azimuthal increments are narrow enough that you get an excellent obscura picture even with the elevations being a step function. It provides a great way to anticipate when obstructions may interfere with an RF or visible LOS. 73, Ken N2WWD Sent from my iPad On Mar 26, 2013, at 2:34 PM, Joseph Armbruster josepharmbrus...@gmail.com wrote: Joe, What tracking program is that? I was thinking of making my satellite icons configurable. This way the satellite would look like the actual satellite. Even better, I could store collada models for them and load them in place of the icon. Oh la la, that's an idea. Joseph Armbruster On Mar 26, 2013, at 7:58 AM, Joe Fitzgerald wrote: On 3/25/2013 6:42 PM, Ken Ernandes wrote: 2. If you decide to give the users the ability to input their location, them the option to provide either a single minimum elevation angle or a local map -- i.e., 360 individual minimum elevations as a function of Azimuth. It's much easier to project this and the user is generally interested in an unobstructed LOS with respect to his/her location. It's not the best resolution but in the image below, you can see how there are cut outs in the circles surrounding NASA's ground stations - the software has clearly implemented the idea Ken outlined above. For example, there is apparently some obstruction to the south east of the Hawaiian tracking station. If the sub-satelite point is inside the white line it's AOS. The surface of the earth visible to the shuttle, on the other hand, is simply a red circle, just faintly visible in this image. http://vault.newsfromspace.com/missions/sts114/STS114_land-5.jpg -Joe KM1P ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: satellite los footprints
My humble suggestion: 1. Implement option 1 for the satellite footprint. 2. If you decide to give the users the ability to input their location, them the option to provide either a single minimum elevation angle or a local map -- i.e., 360 individual minimum elevations as a function of Azimuth. It's much easier to project this and the user is generally interested in an unobstructed LOS with respect to his/her location. 73, Ken N2WWD Sent from my iPad On Mar 25, 2013, at 11:15 AM, Joseph Armbruster josepharmbrus...@gmail.com wrote: I can not decide how to implement ground footprints with my google earth satellite tracker. I figured, since I can't make up my mind, I should get a second (and third, and fourth) opinion. For this thread, I would like to discuss how satellite ground-footprints should be implemented. A quick brainstorm led me to three possible implementations (I am leaning towards 3). For each of these, I assume that a geographic line-of-sight footprint is desired with no RF characteristics taken into consideration: option 1 : assume a spherical earth model and project a polygon downwards towards the footprint - note: this is obviously the easiest approach but will result in the most error option 2 : assume an ellipsoidal earth model and project an irregularly shaped polygon downwards towards the footprint - note: this is arguably more difficult than option 1 and would result in less error option 3 : use a digital elevation model and an ellipsoidal model to cull-out regions that are not visible due to geographic features and project an irregularly shaped polygon downwards towards the footprint - note: In this case, our footprint polygon would have holes cut out for the regions that are culled out by mountain ranges, canyons / etc... Obviously, this would be the most difficult to implement but would likely be the best visual representation. The problem is, I would never dream of distributing DEMs for the entire Earth with my tool, even DTED0 would be absurd in my opinion. I could make the elevation queries accessible using a web-service, but then the user would be tied to the internet. The other option would be to allow the users to download their elevation data into a cache, then the tool would just load / use it. This way the user would only have to obtain the elevation data for their region of interest. Maybe that would be the best approach? I am open to suggestions! If you have any experience visualizing footprints, please let me know. I would be interested in hearing your lessons-learned. These are what the line-of-sight indicators look like right now: Google Earth Satellite Tracker - Line of Sight Update I am open to comments and suggestions, Joseph Armbruster ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Satellite hit by debris from weapon test
I agree -- many of us enjoy getting this news and appreciate the effort involved in collecting this information. 73, Ken N2WWD Sent from my iPad On Mar 11, 2013, at 9:20 AM, JoAnne Maenpaa k9...@comcast.net wrote: Trevor, thanks for all your work on finding the news. It seems Trevor was among the first to pioneer a method of news reporting about amateur radio in space (and, topics interesting to satellite hams) where you roll out the news while it is still timely and providing actionable information ... then, later summarize it into a list of news whether that might be a web site or a weekly news bulletin. -- 73 de JoAnne K9JKM k9...@amsat.org ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: 22% votes
I disagree with the principle of prodding apathetic people to vote. If somebody isn't willing to do the research, fill out a card, and mail it back, then why should we go out of our way to get a vote they themselves apparently don't care about. I'm more interested in the opinions of those who are motivated enough to do this relatively simple task. I don't understand the fixation with getting a higher percentage of the membership to vote. 73, Ken N2WWD Sent from my iPad On Sep 18, 2012, at 4:22 PM, Daniel kf1...@gmail.com wrote: The numbers are low, was there an option to vote on line? That may be something to look at for next year or something like it * Dan ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Software for IPad?
I really like GoSatWatch. 73, Ken N2WWD Sent from my iPad On Jun 17, 2012, at 3:07 AM, Jim Heck j...@milnet.uk.net wrote: Hi All, As a new owner of an IPad, I would be interested in suggestions as the best sat tracking software. Tks and 73s Jim G3WGM ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Model Rocket Booster Engine for Picosatellite
How would attitude be controlled so the thrust is in the correct direction? Spin stabilization about the maximum moment off inertia axis is probably the best choice. This would require a magnetic torquing system. Another issue is the thrust needs to be directed through the spacecraft's center-of-mass or there will be stability problems. How would a cluster be fired individually with each, in turn, directed through the center of mass? That's a complex design problem. One more issue is that when you carry multiple motors, the first must accelerate the mass of the unfired motors, so the early firing will be less effective. The mass of the spent casings will need to be accelerated buy the subsequent motor firings. You do have some work to do before you have a practical solution. 73, Ken N2WWD Sent from my iPad On Jan 17, 2012, at 3:44 PM, Joe Leikhim rhyol...@nettally.com wrote: David; There are some much bigger motors! Ask the Level-3 rocketry folks! Anyway a cluster of medium sized motors could be fired individually as required to raise altitude. I would think that SRB's would be more reliable and safer than hypergolic used on previous Oscars. There would of course be a lot of heat in the rocket casings that would need to be dissipated. -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida www.Leikhim.com jleik...@leikhim.com 407-982-0446 Note to GMail Account users. Due to an abnormally high volume of spam originating from bogus GMail accounts, I have found it necessary to block certain GMail traffic. Please phone me if you believe your message was not received. ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: ARISSat-1 (37772) decay
Try driving at 17,500 mph... -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Tom Williams Sent: Saturday, December 31, 2011 12:43 PM To: Nico Janssen Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: ARISSat-1 (37772) decay Do we really expect the temp to get substantially higher before it begins to tumble? Just sort of thinking about putting my hand out the window of my car, there's a lot of aero force before it gets hot... Tom KJ4EAW On Dec 31, 2011, at 9:46 AM, Nico Janssen ham...@xs4all.nl wrote: Hi, My prediction for the decay of ARISSat 1 still stays on the same date: January 4 +/- 1 day. As the aerodynamic drag increases, the telemetry of the satellite should show ever higher temperatures in the coming days. Especially interesting is the data from the Kursk experiment, that measures the density of the air around the satellite. Happy New Year to all! 73, Nico PA0DLO On 2011-12-22 16:15, Nico Janssen wrote: Hi, My current prediction for the decay of ARISSat 1 is January 4, 2012, +/- 3 days. If solar and geomagnetic activity really increase before the end of December, as some predictions suggest, the decay may be a few days earlier. 73, Nico PA0DLO On 2011-12-11 15:24, Nico Janssen wrote: Hi, Solar activity has remained at relatively low levels. There have not been any M or X class solar flares nor magnetic storms in the past several weeks. As a result, the expected decay date of ARISSat 1 has shifted into January. It is now to be expected around January 3, but depending on solar activity it may be more than 5 days later or earlier. 73, Nico PA0DLO On 2011-11-28 21:36, Nico Janssen wrote: Hi, With its relatively high area to mass ratio, ARISSat 1 is quite sensitive to space weather changes. In the past two weeks solar flux values have been relatively low, around 140, while they were around 180 in the weeks before. Also there have not been any magnetic storms. As a result of this low solar activity, the expected decay date of ARISSat 1 has now slipped to the end of December. My current prediction is 27 December. But if solar activity stays at these low levels, the decay date will even shift into early January. So it is still too early to make any sensible predictions. 73, Nico PA0DLO On 2011-11-18 15:05, Nico Janssen wrote: Hi, So far all my analyses of the evolution of the orbit of ARISSat 1 have resulted in a predicted decay date sometime in December 2011. Actually my current predicted decay date for this satellite is December 17. Obviously it depends very much on how solar activity develops in the coming weeks. So now we have seen decay predictions ranging from December 2011 to April 2012. Let's see how we converge to the actual decay date. 73, Nico PA0DLO ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Geostationary Satellites
A few reasons: 1. There are a finite number of orbital slots at Geostationary. That is essentially like water front property. 2. The satellite's footprint is less than half the Earth, all the time; the same half of the Earth all the time. 3. Those at northern latitudes will always have low elevation angles. 4. A lot of propellant (spacecraft weight) is needed to boost from a transfer to a GEO orbit. 5. A significant amount of additional propellant would also need to be allocated for station-keeping maneuvers to maintain that fixed antenna pointing direction. 6. Because of the fixed footprint, there is less variety of stations available to communicate with (a corollary to #1). All factors considered, the number of operators willing to contribute is severely diminished versus that of a satellite in a molyniya type orbit. These fewer contributors would need to pay for a project that is far more expensive than a Phase 3 program. The bottom line: the benefit of the fixed antenna is outweighed by the negative factors, first and foremost being cost. I hope this helps. 73, Ken Ernandes N2WWD Sent from my iPad On Oct 10, 2011, at 5:23 PM, ka9qjg ka9...@wowway.com wrote: Hello Hope Everyone is doing Well, I know people say no such thing as a dumb question So here goes What is the reason We do not have any Type of geostationary Satellites. Is it because they are for World Wide Use and If stationary one could Hit it 24/7 and Maybe park there butt on it and Run a Beam and Amp and take it over Thanks 73 De Don KA9QJG ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: calculation of eclipse
Unfortunately it's not a simple formula, but rather a process. To compute, you need to not only propagate the satellite orbit (as is done in a tracking program), but also need an algorithm to generate positions of the Sun relative to the Earth. (The latter is available in a book called Astronomical Algorithms by Jean Meeus.) You will also need to consider the diameter of both the Sun and the Earth. The eclipse geometry is explained in the book Satellite Orbits by Montenbruck and Gill. From there you need to develop a sampling method to determine entry and exit times. Bear in mind that the eclipse geometry and timing is different on a case-by-case basis with the exception of some specialized orbits (which ARISSsat is not in). I'm sorry I couldn't offer a more satisfying answer. 73, Ken N2WWD Sent from my iPad On Sep 29, 2011, at 7:33 PM, normn3...@stny.rr.com wrote: Hi all!! How does one calculate the period and time of entry and exit of eclipse? I'm going to be helping a friend do an Arissat presentation for her class. Due to the fact of the battery failing, this gives a 15 minute hold before the power management allows transmission. So, for any chance of receiving the bird, it has to be in sunlight for 15 minutes (or so). I'd prefer a mathematical formula. Echo goes through some of the same trials. Thanks, Norm BTW: I am an engineering student, just throw the math my way. ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: NASA Says ...
It is not an uncertainty. A large satellite can break up and different pieces can re-enter at different times. I experienced this working the orbital decay of the Apollo 9 Lunar Module back in 1981. FYI Apollo 9 did a lunar landing rehearsal in Earth orbit. 73 Ken N2WWD Sent from my iPad On Sep 24, 2011, at 4:11 AM, Paolo Mattiolo matti...@gmail.com wrote: That's incredible that NASA still is not sure with precision where the sat fall down!! 73 de in3aqk On Sat, Sep 24, 2011 at 9:27 AM, Clint Bradford clintbradf...@mac.comwrote: We can now confirm that #UARS is down! Debris fell to Earth between 11:23 p.m. EDT Friday, Sept. 23, and 1:09 a.m. EDT Sept. 24. -NASA Clint Bradford clintbradf...@mac.com ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb -- Paolo Mattiolo Software developer http://www.mattiolopaolo.com cell:347 9454207 skype:paolomattiolo msn:paolomatti...@hotmail.it twitter:IN3AQK ham call sign: IN3AQK IQRP N° 715 ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: ISS Re-supply Spacecraft Fails
It's an opportunity for the SpaceX guys to step up to the plate. Ken Ernandes, N2WWD Sent from my iPad On Aug 24, 2011, at 1:41 PM, B J va6...@gmail.com wrote: snip Goober, Very Bad news. Farrell snip http://www.nasa.gov/mission_**pages/station/living/index.**htmlhttp://www.nasa.gov/mission_pages/station/living/index.html http://www.universetoday.com/88409/breaking-emergency-situation-as-russian-progress-re-supply-ship-fails-to-reach-orbit/ snip There are more links about it at: http://www.spacetoday.net/Summary/5375 There hasn't been much success in launching satellites lately: http://www.spacetoday.net/Summary/5370 http://www.spacetoday.net/Summary/5371 http://www.spacetoday.net/Summary/5372 73s Bernhard VA6BMJ @ DO33 ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: PVC
It works well to fill a PVC pipe with a wood dowel the size of the pipe's inner diameter. Then you just need to weatherproof the ends of the pipe with caps or otherwise. 73, Ken N2WWD On Feb 24, 2011, at 10:58 AM, Glen Zook gz...@yahoo.com wrote: PVC is NOT a structural material. You can sometimes get away with using it for something like a vertical antenna without any real stress. However, using it to support something with any horizontal force is another matter. The colder the weather the more likely it is to fail. Making an A frame or T mast from wood is a much better idea, will support a lot more, and definitely will last considerably longer. Glen, K9STH Website: http://k9sth.com --- On Thu, 2/24/11, Mike1234 mikef1...@buckeye-express.com wrote: Has anyone ever experimented with PVC pipe to use for a mast in place of steel ? I have used it for vertical antennas and stands up excellent to the winds and weather here in Toledo, Ohio . ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: PVC
But if you fill it with the wood dowels, they stay relatively straight and also won't get crushed by the antenna U-bolts. 73, Ken N2WWD On Feb 24, 2011, at 12:07 PM, Bob Bruninga bruni...@usna.edu wrote: PVC is NOT a structural material And no matter how you disguise it with paint or whatever, it still looks like an ugly piece of PVC because they are always naturally curved, limp and bent. Bob, WB4APR ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Wish List, The Ideal VHF/UHF Sat Rig
I'm not normally one to throw cold water on creative ideas, but I will put myself in the position of the potential manufacturer. What any manufacturer would need to even contemplate this project is good answers to a few basic questions: 1. Can I come up with a design to these specifications that I can sell in the realistic price range of the typical amateur operator? 2. Is there a large enough market out there that I can make a profit on this exercise? My guess is the manufacturers wouldn't touch this one with 3.048-meter pole without at least one functioning high altitude satellite on orbit. I realize these are frustrating times, but I think you'll need to come up with more than just a wish list. Perhaps a group could get together and prototype portions to make a plausible case that this can be built economically. Can it be done? Probably... But those who really want it will probably need to invest a lot of sweat equity to prove it. 73, Ken N2WWD -Original Message- From: Mark L. Hammond marklhamm...@gmail.com Sent: Mar 1, 2010 1:55 PM To: MM ka1...@yahoo.com Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: Wish List, The Ideal VHF/UHF Sat Rig How about IF tap (10.7MHz) and high speed packet ready (up to say, 76k or faster)? (Maybe I missed it, but I don't think I saw those 2 features...) 73, Mark N8MH On Mon, Mar 1, 2010 at 1:44 PM, MM ka1...@yahoo.com wrote: My Ideal Competition Grade VHF/UHF Radio Wish list. It seems we are long over do for a Competition grade high performance VHF/UHF transceiver, which can also be used for Satellite operations. There are several competition grade HF transceivers on the market, however there are no high end competition grade VHF/UHF/Satellite systems on the marker. Most of the rigs I have seen which support VHF/UHF are either HF rigs that have had VHF/UHF slapped on, or low end VHF/UHF rigs, with HF slapped on. If we want the Amateur Radio manufactures to build us a GREAT VHF/UHF/Satellite system, then we need to tell them what we need. Here are some suggestions. Constructive comments welcome. This radio does not exist. If the manufactures are interested in providing a new state of the art VHF/UHF radio to the Amateur Radio community, here is one opinion of what should be in next Competition Grade VHF/UHF Transceiver and what should not be in the radio. I am going to give this fictional radio a name HR-956-Pro. What do we need: • We need a competition grade VHF/UHF transceiver that will support Terrestrial-DX, Satellite and EME operations (Voice, CW and Digital-JT65). • The HR-956-Pro, needs to be able to interface with modern computers (HTML Browser, USB and or CAT-5). • The HR-956-Pro, needs to able to interface with modern Externally mounted Pre-amplifier (both power feeds and transmitter sequencing). • The HR-956-Pro, need to be able to interface with modern Solid State Amplifiers and Tube based amplifiers. The RF output per band needs to be standardized with the Amplifier manufactures to prevent transceiver and amplifier failures due to sequencing problems and RF mismatching. • TX/RX Sequencer built-in, to control external Preamps, Amplifies and other accessories (programmable). Receiver: Of course we need a Great receiver, not another mediocre receiver. Each receiver for each band needs to be a Great performer. No Birdies: On a HF rig, a few Birdies do not usually cause serious issues, since the HF users are often listening to signals Above the noise floor. On a Satellite Radio, we are often listening to signals 10-30 dB, Below the Noise floor. Internally generated birdies are a serious problem for weak signal VHF/UHF operations. Filters: Each mode will need its own selection of DSP filters. The filters would also affect one of the Line-level outputs to the external PC. There are times when want to send Filtered or unfiltered audio to your external PC for Digital signal processing. One of the line-level outputs should be taped before the HR-956-Pro Filters, the other line-level output should be taped after the HR-956-Pro filters. The TX and RX filters should be independently selectable. The Filters need to be tested to verify they will support Satellite Mode-J (TX on 2-meters while listening on 435-438) Example: FM-5k, Filters 15k, 10k and 8k filters. AM Filters 10k, 6k, 3k, etc. SSB Filters 4.0k, 3.0k, 2.5k, 2.0k, etc. Other Modes: CW, FM-2.5k, Data Audio Quality: Life is too short for QRP or Poor Audio. It's not the number of contacts that’s important, it’s the quality of the contact. On the audio side, the HR-956-Pro needs to be able to support a wider range of audio through most of the stages. Of course the radio needs to meet FCC and other requirements, however we can still design the radio to deliver a wider bandwidth of good sounding audio. Let's
[amsat-bb] Re: Planet Pseudo-Keps
Your statement is correct, however there is an issue of context. Most satellite tracking software uses Simplified General Perturbations No. 4 (SGP4) as an orbit propagator. SGP4 is one of several orbit propagation algorithms that presume the Earth to be the central attracting body (as both origin and major attracting mass). As such, the associated Keplerian elements are in the context of an Earth-orbiting satellite as are the corresponding output positions and velocities. This is a convenient simplifying assumption for Earth-orbiting satellites and also since Earth station coordinates use the center of the Earth as the origin. Certainly, there are orbit propagation (and ephemeris interpolation) methods that have a different (or a flexible choice of) attracting body (and therefore a different origin and central mass). In using such an algorithm, the software must also (1) know the mass of the central attracting body, (2) compute the Earth's position relative to the origin (the attracting body) and (3) also determine its orientation relative to (for example) the Sun's coordinate system. This requires an additional translation (i.e., vector subtraction) and a re-orientation (i.e., coordinate transformation). These are fairly simple to code into a library and thus simple to use. However, the software needs to have that additional logic already embedded. I do not know of a method in which the Keplerian elements of a planet orbiting the Sun could be used to produce any sort of meaningful answer in software that propagates orbit using an Earth-centered propagator. Indeed, there's nothing wrong with the physics, but one must pay attention to the simplifying assumptions underlying the implemented algorithms. -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of ve4yz Sent: Saturday, February 27, 2010 11:41 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Planet Pseudo-Keps Keplerian Elements have nothing to do with the Earth. To say it only applies to earth orbiting objects would be like saying Newton's laws of motion only apply to the earth. They are mathematical descriptions of the motion of one body orbiting another in an unperturbed orbit using the 6 degrees of freedom of the orbiting body - i.e the 6 key elements of the keps. They predate computers and software; circa 1605. This not to say that they are universally applicable. Larger or smaller as in galactic or subatomic with perturbed orbits - all bets are off. ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Azimuth question
Azimuth is referenced to True North. Some software might allow magnetic, but that would likely be an optional alternative to true north. 73, Ken N2WWD -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Azimuth question Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software? One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north? Randy - N2CUA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: THE DMSP launch
Bob and Dan - I sympathize with what you're saying and know you both have AMSAT's best interests at heart. But unfortunately I don't see this exchange going in a positive direction. We all know this is not the first time somebody has come on this mailing list lacking a constructive motive. It appears that, with such a person, it is a counter-productive to continue the exchange. No matter what meaningful and accurate comments you might make, it will get twisted or otherwise re-interpreted in a negative fashion or in the light most favorable to an ulterior agenda. This is *my opinion* as an AMSAT member and thus *not* something I will debate online, or in private for that matter. Thus understand in advance [Rocky] why I will ignore any non-constructive responses to this message. I think we agree this list is a great thing for those wanting information, having bona fide questions, or wishing to offer a constructive opinion. I will be happy to exchange messages with anybody who (in my opinion) is engaging in something positive or constructive. I would, however, recommend that those of us who have AMSAT's best interest at heart try something different to deal with negativism. My suggestion is to attempt once (and only once) to steer things in a positive or constructive direction. If that fails, simply state that you are not obligated to exchange messages with anybody you believe is not pursing a positive or constructive agenda. Make it incumbent on the person making the objectionable comments to put things back in a positive direction if they wish to get any replies. If everybody who has AMSAT's best interests at heart followed that, I think we'd have much better exchanges on this list. Just a thought... 73, Ken N2WWD -Original Message- From: Robert Bruninga bruni...@usna.edu Sent: Oct 20, 2009 12:22 PM To: 'Rocky Jones' orbit...@hotmail.com, n8...@usa.net, 'Amsat BB' amsat-bb@amsat.org Subject: [amsat-bb] Re: THE DMSP launch so what? We should never on the BB have differences with the direction that the satellite program is going? YOu have to be kidding. No we are not.. You clearly do not understand volunteerism in a highly techincal endeavor where Those that can... DO and Those that can't should contribute or GET OUT OF THE WAY. The only comments I and others have raised or made have been completely professional. No, just incessant whining and no productive contribution. Either BUILD something, or contribute to those that are, or shut up and get out of the way.. (my personal opinion since I have NO position within AMSAT other than as a contributor where I can). And fair questions deserve fair answers. Yes, do some work instead of driviling... go develop some answers, and stop acting like a troll just wasting everyone's time. what have I gotten back? you are a troll Yes, all of your posts seem to meet that definition perfectly... Hope you are having a good morning. I will when I can stop having to read your drivel every morning... Bob ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: THE DMSP launch
Dan - Great points - especially #4 !!! 73, Ken Ernandes N2WWD -Original Message- From: Daniel Schultz n8...@usa.net Sent: Oct 18, 2009 11:51 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: THE DMSP launch Someone wrote: as I recall there were 50 some odd pounds of ballast launched with the bird...to bad it wasnt an amateur repeater. to bad we didnt have something to use that excess performance...they flew ballast on the flight - Why would they fly ballast on their rocket when they could have flown a ham satellite? 1. Ballast does not need to be tested for Electromagnetic Compatibility or contamination of the primary payload. The Interface Control Document for a block of concrete can be exceedingly simple, with no need to pay a room full of engineers to review it for completeness and accuracy. 2. Ballast does not need to have a separation interface tested and qualified, there is no chance of it coming loose inside the payload shroud during liftoff. 3. Ballast is certain to be ready in time for the launch date, without bringing another organization into the mix. There is no need to conduct a crash engineering program to design a satellite structure that will fit on the Atlas and then test and certify the satellite for compliance with the Atlas vibration and acoustic specifications. 4. Ballast does not have an e-mail group full of whining little people who think they could have designed it better or that it operates on the wrong band or mode, and complaining loudly when the mission falls months or years behind its original launch date. If you were the Colonel in charge of the mission, you could not make a safer choice than launching a block of concrete ballast. A ham satellite is just a lot of additional risk and headache with no possible gain for you or your future career. Somewhere in the world there may be an officer who is willing to take that risk. That is how Oscar-1 was launched in 1961. The challenge is to find that person and nurture a relationship with him or her. If they are reading the comments on Amsat-BB they are probably thinking there is no way I would ever want to have a relationship with that wacky organization Dan Schultz N8FGV ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: THE DMSP launch
Dan - Great points - especially #4 !!! 73, Ken Ernandes N2WWD -Original Message- From: Daniel Schultz n8...@usa.net Sent: Oct 18, 2009 11:51 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: THE DMSP launch Someone wrote: as I recall there were 50 some odd pounds of ballast launched with the bird...to bad it wasnt an amateur repeater. to bad we didnt have something to use that excess performance...they flew ballast on the flight - Why would they fly ballast on their rocket when they could have flown a ham satellite? 1. Ballast does not need to be tested for Electromagnetic Compatibility or contamination of the primary payload. The Interface Control Document for a block of concrete can be exceedingly simple, with no need to pay a room full of engineers to review it for completeness and accuracy. 2. Ballast does not need to have a separation interface tested and qualified, there is no chance of it coming loose inside the payload shroud during liftoff. 3. Ballast is certain to be ready in time for the launch date, without bringing another organization into the mix. There is no need to conduct a crash engineering program to design a satellite structure that will fit on the Atlas and then test and certify the satellite for compliance with the Atlas vibration and acoustic specifications. 4. Ballast does not have an e-mail group full of whining little people who think they could have designed it better or that it operates on the wrong band or mode, and complaining loudly when the mission falls months or years behind its original launch date. If you were the Colonel in charge of the mission, you could not make a safer choice than launching a block of concrete ballast. A ham satellite is just a lot of additional risk and headache with no possible gain for you or your future career. Somewhere in the world there may be an officer who is willing to take that risk. That is how Oscar-1 was launched in 1961. The challenge is to find that person and nurture a relationship with him or her. If they are reading the comments on Amsat-BB they are probably thinking there is no way I would ever want to have a relationship with that wacky organization Dan Schultz N8FGV ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Geosyro orbit.
The Earth is approximately 17.4-deg in diameter (8.7-deg radius) from Geosynchronous Earth Orbit (GEO). 73, Ken N2WWD -Original Message- From: Joe n...@mwt.net Sent: Sep 15, 2009 12:07 PM To: BB amsat-bb@amsat.org Subject: [amsat-bb] Geosyro orbit. Hi All, I have a couple of questions, How big is the earth from a geosyncronous (sp?) orbit. Like the Moon from Earth is roughly 1/2 a degree. What is the earth from a geo orbit? anyone know? Joe WB9SBD ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Don't Fly SuitSat2 to ISS (rebuttal)
Great points Dan! I can think of anything I could add. 73, Ken N2WWD -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Daniel Schultz Sent: Sunday, August 23, 2009 12:48 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Don't Fly SuitSat2 to ISS (rebuttal) The worldwide amateur radio community must interface with one unified voice to the various space agencies that form the ISS partnership. The ARISS organization, whatever its flaws may be, was created by the efforts of a lot of hard working hams in many countries to provide that interface. Without it ham radio would have no access to the manned space program, and as a child of the 1960's who grew up with the Mercury, Gemini and Apollo missions, I am thrilled that we hams have such access. I could easily imagine a world where this was not allowed. The fact that we are able to launch anything to the ISS, given the astronomical value of every kilogram of payload mass on the Progress or the Shuttle, and every minute of astronaut and cosmonaut time on orbit, is truly amazing. The recent complaints on the BB remind me of the hams who bash the ARRL without understanding that without the ARRL, amateur radio would have been abolished long ago by the powers that be. We hams need to understand that whatever disagreements exist between us are not nearly as serious as the external threats to our amateur radio avocation. Whatever your beef is, please work within the organization to make it better, and not tear it down in public view. Writing open letters addressed to the worlds space agencies is not helpful to this effort or to your fellow hams. Moving on another amsat-bb thread, AO-40 was designed and built to take advantage of what turned out to be a once in a lifetime opportunity to launch a very large amateur payload into geosynchronous transfer orbit. Had we chosen not to build it, I can imagine lots of people complaining on amsat-bb about how Amsat management had dropped the ball and squandered an amazing launch opportunity. The presence of exotic transponders on AO-40 is not what caused its failure. The 24 GHz payload was contributed by an Amsat member organization and was built because they believed strongly enough in its value that they committed their effort and their funds to get it built. There were transponders on AO-40 to serve every interest, from VHF to UHF to S-band to millimeter wave. Hams MUST push their technical limits and explore new frontiers, it is one of the reasons amateur radio still exists. Critics cried about the complexity of the S-band downlink and then some clever hams took some cheap off the shelf TV down converters, made some slight mods to retune the input frequency, and got a lot of hams active with 2.4 GHz receive capability for very little money. I agree with the letter in this month's QST (September issue, page 24), suggesting that those who complain that the amateur radio has gotten too technical might better enjoy reading People Magazine instead. Dan Schultz N8FGV ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.64/2321 - Release Date: 08/23/09 06:18:00 ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
