Re: [time-nuts] Airraft Ping Timing
Hi, Yes, and there was an early military positioning system, roughly 1960s / 1970s that worked on Dopplar also. The name escapes me at the moment. I think it is Transit. See http://en.wikipedia.org/wiki/Transit_(satellite) Greetings, Pieter. -John = This is how ELT locating satellites work (when not relaying the newer GPS data bursts). Several on another list I watch suggested this pretty early on and I guess INMARSAT got the message. I'd be curious to know if AFRCC pointed INMARSAT in that direction. Really shows the value of precise and stable time references! Date: Mon, 24 Mar 2014 16:06:14 -0700 (PDT) From: J. Forsterj...@quikus.com To:time-nuts@febo.com Subject: [time-nuts] Airraft Ping Timing Message-ID: 13855.12.226.214.5.1395702374.squir...@popaccts.quikus.com Content-Type: text/plain;charset=iso-8859-1 According to a report on FOX, INMARSAT was able to determine the Malasia Air followed the southern traectory from the Dopplar of the pings. They verified their model by tracking other planes. -John = ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Is possible precise 1pps?
Hi, On Wed, 13 Mar 2013 23:51:53 +0100 (CET) hutt...@seznam.cz wrote: NEO-6M buy for less than $ 10 including shipping from China, NEO-6T is unfortunately expensive, and frankly I do not know who sells it for at least a little reasonable prices. The -T models are not that expensive. The problem is that you have to buy them in batches 30 to get down to a reasonable price. U-blox seems to have taken the stance, that small buyers are not really benefitial to their business (which is understandable when you can sell millions of pieces on the chinese market). But they nevertheless support these small buyers trough their webshop where you can buy single pieces (which is far better than most manufacturers who do not sell single pieces at all). Sounds like a time-nuts group buy? I would be interested... Greetings, Pieter. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] The GPS navigation is the weakest point,
Hi, Of course, but then when you switch on your transmitter you are on your own. Considering the speed of a drone (700Km/h?) you need a great coverage, so much RF power out. Easy: Use a dish antenna on the transmitter. Very directional with large ampification. If using a 'moderate' opening angle, just pointing the dish at the drone by hand will work. After starting the system locked to the gps time, once the signal is on the drone, I don't think it matters anymore. (It might not even matter at the start?) The drone will follow the timing of the jammer. As the drone will receive all signals from the single transmitter, the relative timing will be fixed. Just using a OCXO will have a good enough short time stability to allow the system to work, I would think. As the plan is to land or jam the drone within say 10 minutes, long term stability is not that important... Greetings, Pieter. On Fri, Dec 16, 2011 at 12:22 AM, J. Forster j...@quikus.com wrote: You could just have a GPS receiver and use that to sync up the jammer. -John == To transmit a GPS cluster signal you need a GPS simulator to generate the cluster so even a single transmitter can do this, the relative timing and not the different positions of the transmitters is what the receiver sees. When over-powering the real birds you just needs to be close enough in timing, and it is the location of the target which is of interest. If this scenario is true... then they have not done their home-work. I would ask a number of critical questions already from my civilian background. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Precisione GPS based led clock
Hi, Hi Tom, How about using Binary for the last couple of digits? 4 LEDs for a digit in BCD. Saves on pins and wiring. I had the same idea, although my idea was to just make it completely binary and use OCR on the photograph to find the time. Maybe adding 2 surrounding always-on other colored LEDs to frame the sequence would be nice? Greetings, Pieter. Robert G8RPI. From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, 3 November 2011, 16:29 Subject: Re: [time-nuts] Precisione GPS based led clock I also have had need of a high resolution display clock for photographic time stamping. For those of you working on this make sure not to use a LCD or VFD display. The response time is too slow. Also you can rule out any sort of TV display. If using LED make sure not to multiplex the digits. This is a common trick, especially when using microprocessors, and works well for human eyes, but fails completely with high resolution photos. So having ruled out everything but direct drive LED the only other concern is to make sure the decade counters which drive the display are synchronous or at least that all the digits are latched at the same time. Otherwise you get false readouts due to ripple carry or sequential scan. Be careful using a microprocessor for this. For millisecond displays you need a total of 21 pins; for microseconds you need 42 pins. An external serial-parallel (e.g., shift register with latch) chip might be safer since neither a PIC nor an Arduino can update that many pins in one instruction. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lyttleton Time Ball completly collapsed
Pity... Hopefully no one was working on the dismantling when nature decided to help. Soon on eBay - Slightly used timeball - local pickup only... You missed the: Some assembly required ;-P Greetings, Pieter. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Filter
Hi, GPS phased arrays aren't new, nor is it necessary to physically steer the antennae within the aray: http://www.navsys.com/papers/0005004.pdf But would such a system help with the LNA overload due to a local transmitter? I would expect that using separately steered antennas with good directivity could prevent this out-of-band LNA overload? Greetings, Pieter. Bruce Magnus Danielson wrote: On 03/08/2011 05:22 AM, Hal Murray wrote: Since you are after timing off of the sat's, having antennas that move, either physically or electrically seems like a problem. Any shift in the effective antenna location as you tracked the satellite would be exciting to compensate for. There was an early paper published based on doing this (early 80's). You can correct for the antenna orientation. (That's what software is for. :) Radio astronomers have been doing it forever. I think it's simple, at least in the nice/common cases. If the antenna geometry has a point that everything swivels around, consider that to the the location of the antenna. I think that covers the typical alt-az mount: http://en.wikipedia.org/wiki/Altazimuth_mount The point is where those two axes intersect. Now just fudge the coax delay to correct for the time/distance from the real antenna location to that point. That's the before location coax delay (in there with the ionospheric delay) rather than the post GPS antenna-to-box delay. Of course, it gets a bit more complicated than that if you want to track several satellites in real time. That probably takes an antenna per satelite. But again, VLBI geeks have been doing that sort of math for ages. You would need to have a DGPS input stream generated in order to compensate sat for sat. If you don't have a DGPS input to the GPS receiver you are fairly stuck with the shifts... Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Do I have a defective thunderbolt?
Hi, Both slashes work fine for me! That is an artifact of IE on Windows. According to RFC 1738, URLs use the '/' to separate components of a hierarchy. Because MS-DOS (and therefor Windows...) uses '\' as a path separator, people using Windows will type the wrong separator in an URL. That is then 'fixed' by IE, instead of educating the user that the wrong separator is used... Problem is that people also use this wrong separator in html files, resulting in broken images/links :-( Also result of the difference in path separator between Unix and Windows: At my previous company a Sun workstation running Solaris was used as the main controller for the testbench and product, while a lot of people used Windows on the desktop. Sometimes I found files such as '\home\user\datafiles\bla\testresults.txt' on the machine, using the wrong separator. That PC user of course not understanding why the result file was not in his/her home directory :-) Greetings, Pieter. You've mixed up the backslashes used by Windows with the forward slashes expected on the WEB. Links should be: http://www.decampos.net/LH/LH1.png http://www.decampos.net/LH/LH2.pnghttp://www.decampos.net/LH/LH2.png Bruce Geraldo Lino de Campos wrote: For some reason, the links didn´t include the suffix png. The correct linkas are www.decampos.net\LH\LH1.png www.decampos.net\LH\LH2.png -- Raj, VU2ZAP Bangalore, India. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Have Quick Tools
Hey, On Aug 23, 2010, at 7:52 AM, Brooke Clarke wrote: Has anyone made a PIC based Have Quick device to either compare two have quick outputs, generate a HQ data stream or read a HQ stream? I've been interested in playing with the HQ outputs of my HQ-compatible GPS receivers for a long time. It's on my list of things to do before the heat death of the universe, but there are a lot of projects ahead of that one. Not that it matters since there are so many projects ahead of it, but if I was going to do this today I'd probably use a TI MSP430 family processor, since those are what I'm presently set up to develop for. Hmm, maybe one could set up one of those Chronos wristwatch development kits to automatically set the watch time from a HQ source over its wireless link? You know what they say: Measure it with a micrometer, mark it with a chalkline, and cut it with a chainsaw! :-D I would just use an axe for that, much less precise };-P And of course for the measuring I would use a laser interferometer based system, with nm precision! Greetings, Pieter. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] What FreeBSD version for Soekris net4501 NTP server?
Hello, Do people on the list have a preference for using a specific version of FreeBSD for a ntpd/ntpns server running on a Soekris net4501 board? I finally ordered (and promptly received) the Soekris net4501 board that I wanted to connect to my Thunderbolt. Having to start fresh (not having a FreeBSD machine...) I can choose any version... Any reasons not to use the latest (bleeding edge) version? All 'How To Soekris ntp' info on the internet are for older versions of FreeBSD, but those pages are then also from way back... Thanks, Pieter. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] iPhone app
Hi, On 17 Feb 2010, at 07:37, Thomas A. Frank wrote: I don't believe that there is a 1pps available to the OS. The GPS chipset seems to provide a very limited amount of data to the phone. For example, there does not appear to be any way to get satellite status info from the GPS chip to the OS. At least none of the apps I've tried thus far (and I've tried a fair number) provide anything like that. The iPhone OS provides an 'Location Manager' that will (try to) provide a location based on available hardware and environment: The hardware might not have a GPS (Early iPhone, iPod touch) or you might be indoors. The system will try to get a location using WiFi access points (Skyhook Wireless) and/or Cell tower triangulation and GPS if available and determines heading based on either a compass or position differences. I would assume that the GPS hardware provides the satellite information, but to abstract the used method, the Location Manager does not provide the satellite info. For the average consumer it is not really interesting, they just want to know where they are... However: I am disappointed that my iPhone, although: - Having a GPS - Having a data connection usable for (S)NTP - Is a participant in the cell phone network - Sometimes connected via USB to iTunes for syncing content and performing a backup is still not displaying the correct time. (Not even having a 'Set Now' button...) Using the location even the time zone can be set, although the user might want to override that one to stay in sync with home. But for (modern) cell phones to not have a notion of the correct time is disappointing... All my previous cell phones had the same problem: Present in the GSM network, but you still have to set the time. As I synchronize my calendar with the desktop, they will both give an alert for an appointment, but they have a delta of many seconds... Hoping this will be fixed in iPhone OS 4.0... Grrr, Pieter. Tom Frank On Feb 17, 2010, at 12:23 AM, Jim Palfreyman wrote: Hi all, Having recently acquired a new iPhone with a built in GPS, I was wondering if anyone is aware of an application that uses the GPS 1PPS to produce accurate time. I seem to remember reading somewhere that it is not possible to adjust the internal clock, but one could still produce an accurate time display based on the GPS 1 PPS and even provide time pips. Combine that with the internal video there seems a myriad of possibilities. However, trying to find such applications is a large effort and I was hoping the time-nuts community may be aware of some time-aware cleverness on the iPhone. Regards, Jim Palfreyman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS from a window seat
Hello Bill, Group, I'll be flying around the world from Minnesota, USA, to Kuala Lumpur, Malaysia, to give a talk on industrial process control. Bought a Garmin 60CSx handheld GPS so I could tell precisely when I crossed the date line (a man's gotta have some goal in life). Is this feasible? Can you see enough satellites from an airliner window while crossing the Pacific from Los Angeles to Singapore? What side would work better, N or S? I also have a Garmin 60CSx and it worked nicely flying from Amsterdam to Rovaniemi, Finland (via Helsinki), most of the time about 15 meters accuracy. I was sitting at the window seat and just put it in the net from the seat in front of me (I was sitting 3 times in seats 7A and once in 11A, all on a Airbus 320) (Just in front and behind the wing). Sometimes the GPS lost lock (e.g. during banking), I think it would have performed better if it was in a middle seat, e.g. 7C, or a bit higher. When I heard the 'lock lost' beep I just picked up the GPS, let it lock again and put it back in the seat netting. It worked perfectly in the seat table, but that was not very handy, e.g. during dinner... No idea if the GPS reception would behave differently over the Pacific... I did this to get a complete GPS trace of my holiday to the North Cape, to be able to geotag my photos (And because it was fun ;-) ). Greetings, Pieter. Regards, Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RoHS Solder
Hello, China have set up a pilot plant to extract Uraniun from coal fired power station ash. The concentration is the same as medium grade ore, but they don't have to mine it. If a US nuclear power station relased as much radiocative material as the average coal fired one it would be shut down! There is the same strange thing with mercury: According to this article in Popular Mechanics, if you factor in the higher energy usage of an incandescent bulb, because of the mercury that is released from a coal fired power station, even if you crush the CFL at EOL, the total value would be much less for the CFL! (And of course, we all dispose of those nasty mercury containing CFLs properly, don't we?) http://www.popularmechanics.com/blogs/home_journal_news/4217864.html Greetings, Pieter. Robert. --- On Fri, 25/9/09, d.sei...@comcast.net d.sei...@comcast.net wrote: From: d.sei...@comcast.net d.sei...@comcast.net Subject: Re: [time-nuts] RoHS Solder To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Friday, 25 September, 2009, 8:16 AM It's not the silver I'm worried about. I saw a report on a website about 8 months ago regarding the scarcity of many of the rare earths that drive solar, etc (yes, I've tried to find the report again, but can't). This was prior to the whole China export thing. It predicted that many vital elements would be mined out by the 2015-2020 time frame. I wonder how long it will be until we start mining old garbage dumps for metals. -Dave .. ... Another part of the scam is that only two companies (one a University if I remember correctly, one a Japanese company) hold the patents to the Silver based solder that everyone now needs to use... And according to the USGS we are quickly running out of mineable Silver.. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP Journal 10811 article
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Hello Jose, On 18 Oct 2007, at 20:28, Jose Manuel wrote: Mark, I tried it again but the problem persists with this link on page 20. I just downloaded it from the HP link and can read page 20 without problems using Preview on Mac OS X 10.4.10. Maybe the file is somewhat broken and your pdf reader is rejecting the specific page? BTW, interesting article, thx for the link. Greetings, Pieter. Nigel and Phil helped me and I got finally the complete article. Regards, José, EA1PX - Original Message - From: Mark Huffstutter [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 18, 2007 4:08 AM Subject: Re: [time-nuts] HP Journal 10811 article Jose, You might need to download the .pdf again, I just grabbed it and page 20 is OK. And thank you for mentioning the issue, it does indeed look good! Best Regards, Mark On Tue, 16 Oct 2007 17:09:56 +0200, Jose Manuel wrote I´ve just tried to download this interesting article here: http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1981-03.pdf, but page 20 appears blank. Does anyone have this page? Thanks, José, EA1PX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Información de NOD32, revisión 2599 (20071017) __ Este mensaje ha sido analizado con NOD32 antivirus system http://www.nod32.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
