Re: [time-nuts] GPS PRN vs SV...??
tvb wrote: If any of you know of another satellite tracking web site that shows SVN23/PRN32, let us know, ok? Hi Tom. I have an old DOS freeware application (will run under XP etc) that will show you the GPS sats above a nominated site (using the almanac keplerian elements): http://www.geocities.com/kiwi_36_nz/alm2pos/alm2pos.htm I just checked with the latest YUMA almanac from: http://www.navcen.uscg.gov/gps/current/current.alm and it still works (even with PRN 32). It shows you the sateliite position (even it is marked as unhealthy in the almanac). Regards Kiwi Geoff. http://www.geocities.com/kiwi_36_nz ___ 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 PRN vs SV...??
Another way to look at the problem is to view the GPS system interface control document at: https://gpstest.46tg.af.mil/webpub/general/BBS.nsf/0/cb09775cdcb7eb6e8825662d0056ee92/$FILE/icd200c.pdf Where the term of SVID is introduced (page 8), SVID has the same value as the PRN # (for PRN# = 1 - 32). Not to be confused with the SVID's on page 105 which are used to denote data pages. It would appear that the SVN isnt actually broadcast, at least as far as can tell. Bruce ___ 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 PRN vs SV...??
Magnus Danielson wrote: Bruce, Although it is labelled as SV number, my version of the documentation clearly states that the meaning of byte 4 is the SV PRN#. It actually does not clearly states that in my documentation. It contradicts itself! Byte Item Type Value Meaning 2Sat PRN # UINT8 0 Data that is not satellite ID-specific 1 to 32 Satellite PRN number Byte Item Type Meaning 4SV number UINT8 SV PRN number The field SV number (which is what we are looking for) is said to have the meaning of SV PRN number. Perhaps Trimble's SV number = GPS SVID (as defined on page 8 of the GPS Interface control document) for SVs: SVID = PRN#. However as you say since the PRN# is given in the common 4 byte header this would seem somewhat redundant. With the above writing, you can almost assume it is a documenation miss, but it needs to be confirmed. If you look at the Item numbers, they match what is in the ICD-200 so it is likely they have propper meanings. Also notice how the PRN number field is limited in the range 1-32 where as no such limitation is given for the SV number. The documentation is certainly inconsistent and confusing. Inconsistent and confusing yes, but there is only 4 characters too much that cause that confusion. If you assume they should not be there it makes perfectly sense. I guess the operational test is: Does the displayed SV number contain values greater than 32 (current values for SVN can be as high as 61, the maximum value for PRN is 32)? If so then its very likely to be the SVN and not the PRN. Rather, when dumping this, we can verify that the PRN numbers in byte 2 and SV number in byte 4 matches the PRN and SVN mapping available. To help confuse things, I noticed that there is still birds having the same PRN and SVN numbers. Cheers, Magnus Hej Magnus Perhaps all is explained, if one notes that the SVID's described in the GPS Interface Control document are identical to the SV PRN# except when SVID is used to differentiate between data pages. PRN# can be as high as 37 (but not for SVs which are limited to a maximum of 32). I didnt find any mention of the SVN # in the Interface Control document so maybe it isnt broadcast (or at least it isnt publicly available via GPS messages). The Motorola M12+ user manual indicates that the SVID is used in some messages. Has anyone dumped Thunderbolt report packets 0x58 to a text file? Bruce ___ 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 PRN vs SV...??
From: Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 09 Feb 2008 21:57:57 +1300 Message-ID: [EMAIL PROTECTED] Hej Bruce, It actually does not clearly states that in my documentation. It contradicts itself! Byte Item Type Value Meaning 2Sat PRN # UINT8 0 Data that is not satellite ID-specific 1 to 32 Satellite PRN number Byte Item Type Meaning 4SV number UINT8 SV PRN number The field SV number (which is what we are looking for) is said to have the meaning of SV PRN number. Perhaps Trimble's SV number = GPS SVID (as defined on page 8 of the GPS Interface control document) for SVs: SVID = PRN#. Yes, but SVID isn't SVN, which may be the cause of confusion. Actual SVNs isn't meaningfull for normal GPS users and bears no meaning to the receivers, where SVID and PRN# is the important things. Perhaps all is explained, if one notes that the SVID's described in the GPS Interface Control document are identical to the SV PRN# except when SVID is used to differentiate between data pages. PRN# can be as high as 37 (but not for SVs which are limited to a maximum of 32). It would appear that during normal operation PRN# is set to the SVID. There is actually a SVID to PRN# mapping provided, but the SVID range isn't free enought to hold SVN numbers. I didnt find any mention of the SVN # in the Interface Control document so maybe it isnt broadcast (or at least it isnt publicly available via GPS messages). Looking into IS-GPS-200D I am inclined to agree. The Motorola M12+ user manual indicates that the SVID is used in some messages. Has anyone dumped Thunderbolt report packets 0x58 to a text file? Requesting data for PRN# 1-32 and hex-dumping the result would be of interest. 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.
Re: [time-nuts] GPS PRN vs SV...??
On Sat, 2008-02-09 at 14:03 +1300, Bruce Griffiths wrote: Current status SVNs, PRN etc at: http://www.navcen.uscg.gov/navinfo/Gps/ActiveNanu.aspx Bruce Beeing a time-nut, this is an alternative site http://tycho.usno.navy.mil/gpscurr.html -- Björn ___ 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 PRN vs SV...??
From: Björn Gabrielsson [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 09 Feb 2008 10:17:58 +0100 Message-ID: [EMAIL PROTECTED] On Sat, 2008-02-09 at 14:03 +1300, Bruce Griffiths wrote: Current status SVNs, PRN etc at: http://www.navcen.uscg.gov/navinfo/Gps/ActiveNanu.aspx Bruce Beeing a time-nut, this is an alternative site http://tycho.usno.navy.mil/gpscurr.html It is a more handier site for an overview... but the former one has more operational detail and the official messages. Good but for different usages. 31 sats listed in constellation, 30 in normal operation (of which 2 have scheduled maintenance) and now 1 is upcomming for inclusion. Having a quick look through it, PRN 07 is currently not used. It is probably wise to use SVN 23 on PRN 32. If there is a problem there, shut the old bird up. The next GPS IIR-M satellite we could expect at PRN 07. 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.
Re: [time-nuts] GPS PRN vs SV...??
Tom Van Baak wrote: Current status SVNs, PRN etc at: http://www.navcen.uscg.gov/navinfo/Gps/ActiveNanu.aspx Bruce That's a good URL. Thanks. More on the SVN vs. PRN issue... When I mistrust a GPS receiver and want to check where a satellite really is, I use the NASA satellite tracker: http://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.html If any of you haven't heard of, or used this java applet yet, I highly recommend it. After you click on +J-TRACK 3D, click on Satellite-Select and pick any GPS satellite. The only trouble: our SV of interest, GPS BIIA-10 (PRN 32), is missing from the list (perhaps because it is still marked unhealthy?), so we can't get its orbit or ground track. I sent a note to NASA and we'll see if they fix it. If any of you know of another satellite tracking web site that shows SVN23/PRN32, let us know, ok? By the way, if one takes a screen capture of each GPS SV in the Jtrack3D list, you get this cute GPS orbit animation: http://www.leapsecond.com/pages/gps-orbit/ /tvb Thanks Tom, I'm trying to follow this discussion with my limited knowledge and see if my HP z3816a with a UT receiver knows about this new satellite. My random looks have seen a 31 PRN but not a 32. So knowing when the new 32 should be visible in N. Cal would help a lot. I tried your link to the nasa.gov jtrack page, but I don't see how I get to anyplace where I can select a GPS satellite to track. Sorry if I missed something obvious. Any hints or clarifications on how to predict when any gps satellite should be in view here are appreciated. I think I could get Ham satellite tracking software and find the ephemeris information for the satellites somewhere, but I was hoping for an easy way for just the GPS sats. Thanks for the heads-up on the new satellite with this binary new-bit PRN. (That is the potential issue with why some receivers may not handle it -- correct?) ___ 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 PRN vs SV...??
From: Rex [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 09 Feb 2008 02:16:28 -0800 Message-ID: [EMAIL PROTECTED] Tom Van Baak wrote: Current status SVNs, PRN etc at: http://www.navcen.uscg.gov/navinfo/Gps/ActiveNanu.aspx Bruce That's a good URL. Thanks. More on the SVN vs. PRN issue... When I mistrust a GPS receiver and want to check where a satellite really is, I use the NASA satellite tracker: http://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.html If any of you haven't heard of, or used this java applet yet, I highly recommend it. After you click on +J-TRACK 3D, click on Satellite-Select and pick any GPS satellite. The only trouble: our SV of interest, GPS BIIA-10 (PRN 32), is missing from the list (perhaps because it is still marked unhealthy?), so we can't get its orbit or ground track. I sent a note to NASA and we'll see if they fix it. If any of you know of another satellite tracking web site that shows SVN23/PRN32, let us know, ok? By the way, if one takes a screen capture of each GPS SV in the Jtrack3D list, you get this cute GPS orbit animation: http://www.leapsecond.com/pages/gps-orbit/ /tvb Thanks Tom, I'm trying to follow this discussion with my limited knowledge and see if my HP z3816a with a UT receiver knows about this new satellite. My random looks have seen a 31 PRN but not a 32. So knowing when the new 32 should be visible in N. Cal would help a lot. I tried your link to the nasa.gov jtrack page, but I don't see how I get to anyplace where I can select a GPS satellite to track. Sorry if I missed something obvious. Any hints or clarifications on how to predict when any gps satellite should be in view here are appreciated. I think I could get Ham satellite tracking software and find the ephemeris information for the satellites somewhere, but I was hoping for an easy way for just the GPS sats. Ephemeris data is alread available: http://www.navcen.uscg.gov/archives/gps/2008/ALMANACS/SEM/039.AL3 32 23 0 1.44729614257812E-02 9.04464721679688E-03 -2.53930920735002E-09 5.15345068359375E+03 9.07266139984131E-01 -4.24016833305359E-01 -3.47391366958618E-01 2.25067138671875E-04 1.09139364212751E-11 63 9 Should be sufficient to predict sky-view. We don't know yeat at what time it is expected to be set operational. We need to await another NANUS detailing that, as being indicated in NANUS 2008016: http://www.navcen.uscg.gov/archives/gps/2008/NANUS/2008016.nnu Thanks for the heads-up on the new satellite with this binary new-bit PRN. (That is the potential issue with why some receivers may not handle it -- correct?) Indeed. :) 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.
Re: [time-nuts] GPS PRN vs SV...??
J-track is nice. I also use Heavens Above. You do need to register, but it's free. For PRN32, once you log in, use spacecraft # 22657 (Navstar 32) This URL will show the current orbital track. http://www.heavens-above.com/orbitdisplay.asp?Session=kebgcpaanhagkcceebmhgcnbsatid=22657 For all the orbital kep elements I use Space Track. www.space-track.org 73, Mike N1JEZ AMSAT #29649 A closed mouth gathers no feet - Original Message - From: Rex [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Tom Van Baak wrote: Current status SVNs, PRN etc at: http://www.navcen.uscg.gov/navinfo/Gps/ActiveNanu.aspx That's a good URL. Thanks. More on the SVN vs. PRN issue... When I mistrust a GPS receiver and want to check where a satellite really is, I use the NASA satellite tracker: http://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.html If any of you haven't heard of, or used this java applet yet, I highly recommend it. After you click on +J-TRACK 3D, click on Satellite-Select and pick any GPS satellite. The only trouble: our SV of interest, GPS BIIA-10 (PRN 32), is missing from the list (perhaps because it is still marked unhealthy?), so we can't get its orbit or ground track. I sent a note to NASA and we'll see if they fix it. If any of you know of another satellite tracking web site that shows SVN23/PRN32, let us know, ok? By the way, if one takes a screen capture of each GPS SV in the Jtrack3D list, you get this cute GPS orbit animation: http://www.leapsecond.com/pages/gps-orbit/ /tvb Any hints or clarifications on how to predict when any gps satellite should be in view here are appreciated. I think I could get Ham satellite tracking software and find the ephemeris information for the satellites somewhere, but I was hoping for an easy way for just the GPS sats. Thanks for the heads-up on the new satellite with this binary new-bit PRN. (That is the potential issue with why some receivers may not handle it -- correct?) ___ 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] cs beam tube failure???
I opened the box for the first time,,the unit was new and still in the vac bag..the ion current started out and has remained at .6ua..always locks in about 15-18-min..one other unit he had for sale that the seller had opened and had running had a (for two days)had a emult of 1715 and also .6 ua current..when I got there to pick up my unit his emult had also dropped from 1715 to 1700 in 24 hrs time.. one note when I power down or put my unit into standby the pump current will go down to .4 and even .2 but not for long ,,,after running for several days it usually goes back up to .6..I just had it in standby last night for a few minutes and it is still at .4 ua today.but now shows 1295 emult volts... the unit locked for its first time after 2+ years in storage in 21 minutes...the calibration certificate shows a manuf date of may 11,2005..but when I called them they said these were no longer under factory warranty because agilent only offered a 3 yr warranty..and this was one of the very last agilent units made.. - Original Message - From: Dave Carlson [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, February 09, 2008 1:47 AM Subject: Re: [time-nuts] cs beam tube failure??? David, I had a similar concern about a brand new 5071a I just purchased,This unit is dated may of 05 and was first powered up Jan 2 of this year.. If it's really been turned off all that time, I'm surprised that it was able to power up. Was the Ion Pump current much higher for some period of time before it came down to 6 uA? How do you know it was manufactures in May 2005? the ion pump has remained constant at 6 ua This may be as low as it's going to get. You might try putting the 5071A in standby mode for 24 hours or so, to allow just the Ion Pump and not the Cs Oven to operate. It might bring down the internal gassing a bit. But then again that may be as low as you get. It's not abnormal, especially for older CBT, or one that has been allowed to accumulate internal vapor pressure. but I the electron mult volt has been dropping about 1-2 volts per day since then.it started out at 1525 and is now at 1297 and still falling This is fine, and well within expected operation. The 5071A automatically adjusts the EMult voltage to maintain the 100 nA beam current. You have plenty of room to drop without concern. The good thing is that the lower you go, the more headroom you'll have when ultimately the beam current begins to weaken and need increasing EMult to maintain. It should eventually flatten out before it starts to rise. If it does get down to 800 to 600 volts without flattening out, then it will very likely have a problem. It may be a symptom of lots of internal gassing that is getting too much background signal to the EMult dynode. No cure for that but to send it in for repair. all the other parameters are fine but I noticed the osc freq control has been dropping also it is now at -6.84,started out at -5.50.. This is fine. You don't have to worry until and if it gets to 50% or more. Then it's time to tune it in, which is a bit tricky. Get copies of the OP and Service manuals from the Symmetricom web site in PDF format and you'll have many of these answers. do you think these is a problem with this tube?it is a high perf..should still be under warranty as the manual says there is a 5 year warranty on tubes 4240 prefix.. You appear to have purchased a good 5071A. Did you buy it used? One obvious question is: Is it locked? Dave ___ - Original Message - From: David Welch [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, February 08, 2008 9:59 AM Subject: [time-nuts] cs beam tube failure??? Dave, I had a similar concern about a brand new 5071a I just purchased,This unit is dated may of 05 and was first powered up Jan 2 of this year..the ion pump has remained constant at 6 ua but I the electron mult volt has been dropping about 1-2 volts per day since then.it started out at 1525 and is now at 1297 and still falling all the other parameters are fine but I noticed the osc freq control has been dropping also it is now at -6.84,started out at -5.50..do you think these is a problem with this tube?it is a high perf..should still be under warranty as the manual says there is a 5 year warranty on tubes 4240 prefix.. have you ever run into this before?any suggestions..Thanks David ___ 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 PRN vs SV...??
Trimble also offers a freeware planning program. There's a few other of the big name companies that offer similar products. It will tell you when a satellite will be in view and lots of other great info. http://www.trimble.com/planningsoftware.shtml ___ 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 PRN vs SV...??
Hi Mike, Ah, thanks for the heavens-above link. I use that site for Iridium flare predictions; I see now it's perfect for GPS also. Cool. So PRN32 finished its track between Australia and New Zealand some hours ago and is now heading up the Pacific, to Alaska, and then later today, right down the US west coast; over my head. /tvb J-track is nice. I also use Heavens Above. You do need to register, but it's free. For PRN32, once you log in, use spacecraft # 22657 (Navstar 32) This URL will show the current orbital track. http://www.heavens-above.com/orbitdisplay.asp?Session=kebgcpaanhagkcceebmhgcnbsatid=22657 For all the orbital kep elements I use Space Track. www.space-track.org 73, Mike N1JEZ AMSAT #29649 A closed mouth gathers no feet ___ 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 PRN vs SV...??
Trimble also offers a freeware planning program. There's a few other of the big name companies that offer similar products. It will tell you when a satellite will be in view and lots of other great info. http://www.trimble.com/planningsoftware.shtml Jason, Thanks for that one too. Very nice set of plots from that tool. For others trying to get this software to show PRN32 - I found the trick is to change Health: 063 to Health: 000 for PRN32 in the almanac file before you import it; otherwise the software won't display anything for G32. /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.
Re: [time-nuts] GPS PRN vs SV...??
From: Tom Van Baak [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 9 Feb 2008 10:03:41 -0800 Message-ID: [EMAIL PROTECTED] Tom, Ah, thanks for the heavens-above link. I use that site for Iridium flare predictions; I see now it's perfect for GPS also. Cool. Indeed. Comming up my way soon. Hmm. I have a few GPS receivers to rig in the lab, as well as solder some cables. Thanks for reminding me. So PRN32 finished its track between Australia and New Zealand some hours ago and is now heading up the Pacific, to Alaska, and then later today, right down the US west coast; over my head. DUCK! (We want PRN32 active for a while...) 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.
Re: [time-nuts] GPS PRN vs SV...??
Hi: It's 12:15 Pacific time and the heavens above site is showing 32 over the west coast, but my Motorola M12T+ says 11 Visible 11 tracked: PRN tracked: 6, 10, 15, 16, 18, 21, 22, 24, 26, 29, 30 Since it's a 12 channel receiver it should be there. Is there a way to get the M12T+ reflashed? Have Fun, Brooke Clarke http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam ___ 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 PRN vs SV...??
From: Brooke Clarke [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 09 Feb 2008 12:20:31 -0800 Message-ID: [EMAIL PROTECTED] Hi: It's 12:15 Pacific time and the heavens above site is showing 32 over the west coast, but my Motorola M12T+ says 11 Visible 11 tracked: PRN tracked: 6, 10, 15, 16, 18, 21, 22, 24, 26, 29, 30 Since it's a 12 channel receiver it should be there. Not yeat. It is still not set healthy, so your M12T+ is doing the right thing for now. Sit tight for 10 days and look then. Then you will hopefully have good use of all 12 channels. Is there a way to get the M12T+ reflashed? Well, should not be too hard with the supporting software. I haven't seen any software having health-override, which would be needed. 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.
Re: [time-nuts] GPS PRN vs SV...??
On Feb 9, 2008 7:13 AM, [EMAIL PROTECTED] wrote: ...I also use Heavens Above. You do need to register, but it's free. For PRN32, once you log in, use spacecraft # 22657 (Navstar 32) I believe PRN 32 is actually Navstar BIIA-10 (aka 2A-10), COSPAR: 1990-103A, or US Control #20959. and is identified as Navstar 22 in Heavens Above. Based on the first 2 lines of http://celestrak.com/NORAD/elements/gps-ops.txt GPS BIIA-10 (PRN 32) 1 20959U 90103A ... -Michael Taylor ___ 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 PRN vs SV...??
Based on the first 2 lines of http://celestrak.com/NORAD/elements/gps-ops.txt GPS BIIA-10 (PRN 32) 1 20959U 90103A ... It checks out. Thus, you should be looking at: http://www.heavens-above.com/orbitdisplay.asp?Session=kebgcpaanhagkcceebmhgcnbsatid=20959 Tom, you don't have to duck on this pass. :) Cheers, Magnus Good. This new, correct satid also means the ground tracks from heavens-above and from the Trimble Planning program now agree. Thanks, /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.
Re: [time-nuts] GPS PRN vs SV...??
From: michael taylor [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 9 Feb 2008 16:13:08 -0500 Message-ID: [EMAIL PROTECTED] On Feb 9, 2008 7:13 AM, [EMAIL PROTECTED] wrote: ...I also use Heavens Above. You do need to register, but it's free. For PRN32, once you log in, use spacecraft # 22657 (Navstar 32) I believe PRN 32 is actually Navstar BIIA-10 (aka 2A-10), COSPAR: 1990-103A, or US Control #20959. and is identified as Navstar 22 in Heavens Above. Indeed. Checking ftp://tycho.usno.navy.mil/pub/gps/gpsb2.txt gives LAUNCH LAUNCH FREQUS SPACE ORDERPRN SVN DATESTD PLANE COMMAND ** - IIA-10 32 23 26 NOV 1990Rb E5 20959 Based on the first 2 lines of http://celestrak.com/NORAD/elements/gps-ops.txt GPS BIIA-10 (PRN 32) 1 20959U 90103A ... It checks out. Thus, you should be looking at: http://www.heavens-above.com/orbitdisplay.asp?Session=kebgcpaanhagkcceebmhgcnbsatid=20959 Tom, you don't have to duck on this pass. :) 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.
Re: [time-nuts] GPS PRN vs SV...??
Hej Magnus Attached screenshot is for the Furuno GPS receiver in a Z3815A. This indicates that the receiver can see SVN 23 (PRN 32) with no difficulty. However for a supposedly 8 channel receiver it sees 11 SVs?? The M12+T doesnt see it although its only tracking 10 SVs. Bruce inline: Furuno_3.gif___ 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 PRN vs SV...??
From: Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sun, 10 Feb 2008 10:58:42 +1300 Message-ID: [EMAIL PROTECTED] Hej Magnus Hej Bruce, Attached screenshot is for the Furuno GPS receiver in a Z3815A. This indicates that the receiver can see SVN 23 (PRN 32) with no difficulty. However for a supposedly 8 channel receiver it sees 11 SVs?? That's not what it is saying. It says it tracks 6 SVs and expects another 5 in the sky-view. This is just the same as with the Z3801A. Only 6 channel mode. The M12+T doesnt see it although its only tracking 10 SVs. The 10 SVs which is healthy in the current skyview, yes. 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.
Re: [time-nuts] GPS PRN vs SV...??
On Feb 9, 2008 4:58 PM, Bruce Griffiths [EMAIL PROTECTED] wrote: This indicates that the receiver can see SVN 23 (PRN 32) with no difficulty. However for a supposedly 8 channel receiver it sees 11 SVs?? I suspect that as long as less than 8 SV are being tracked (6 in your sample), it only needs one channel to not track the other 5 SV. The not tracked SV are not necessary being updated in a timely fashion so a one or more unused channels could be used to cycle through all SVs / PRNs from the almanac to look for new SV visibility and see if any of the not tracked SV have become suitable to track. -Michael Taylor ___ 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 PRN vs SV...??
On Sat, 2008-02-09 at 17:12 -0500, michael taylor wrote: On Feb 9, 2008 4:58 PM, Bruce Griffiths [EMAIL PROTECTED] wrote: This indicates that the receiver can see SVN 23 (PRN 32) with no difficulty. However for a supposedly 8 channel receiver it sees 11 SVs?? I suspect that as long as less than 8 SV are being tracked (6 in your sample), it only needs one channel to not track the other 5 SV. The not tracked SV are not necessary being updated in a timely fashion so a one or more unused channels could be used to cycle through all SVs / PRNs from the almanac to look for new SV visibility and see if any of the not tracked SV have become suitable to track. -Michael Taylor Hi Michael, You only need to track one SV to get almanac (coarse ephemeris) data for the whole constellation. Almanac data gives you SV position within a few km, which is plenty good for visibility calculations. However to have current ephemeris data you would need to cycle an unused channel through the visible SV every so hour. -- Björn ___ 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 PRN vs SV...??
From: michael taylor [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? Date: Sat, 9 Feb 2008 17:12:29 -0500 Message-ID: [EMAIL PROTECTED] Michael, Oh... hat's off for putting us straight! On Feb 9, 2008 4:58 PM, Bruce Griffiths [EMAIL PROTECTED] wrote: This indicates that the receiver can see SVN 23 (PRN 32) with no difficulty. However for a supposedly 8 channel receiver it sees 11 SVs?? I suspect that as long as less than 8 SV are being tracked (6 in your sample), it only needs one channel to not track the other 5 SV. The not tracked SV are not necessary being updated in a timely fashion so a one or more unused channels could be used to cycle through all SVs / PRNs from the almanac to look for new SV visibility and see if any of the not tracked SV have become suitable to track. Actually, this look exactly like the Z3801A state-view. Notice that the 5 other birds are not tracked at all, they are just known to be in the sky view and when there is a free channel or better geometry it swaps an old bird out and toss in the best selection in the view. Only then it makes attempts to track it. 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.
Re: [time-nuts] GPS PRN vs SV...??
Michael, You're right! That's what I get for rushing through the list before I went to work... Good catch! Mike - Original Message - From: michael taylor [EMAIL PROTECTED] Subject: Re: [time-nuts] GPS PRN vs SV...?? On Feb 9, 2008 7:13 AM, [EMAIL PROTECTED] wrote: ...I also use Heavens Above. You do need to register, but it's free. For PRN32, once you log in, use spacecraft # 22657 (Navstar 32) I believe PRN 32 is actually Navstar BIIA-10 (aka 2A-10), COSPAR: 1990-103A, or US Control #20959. and is identified as Navstar 22 in Heavens Above. Based on the first 2 lines of http://celestrak.com/NORAD/elements/gps-ops.txt GPS BIIA-10 (PRN 32) 1 20959U 90103A ... -Michael Taylor ___ 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] SVN32 and GPS receivers, 32-bit limitations
SatId 20959 GPS SVN32 should now be visible here in Seattle but I have no success seeing it with either a Thunderbolt, an Oncore VP, a Datum 2000, or an M12. True, the satellite is marked unhealthy so it is expected not to see it in the GUI or the timing solution. However, I am also logging raw Motorola binary messages out of the M12, including the @@Ha status message which reports unhealthy as well as healthy satellites, I think. Still no SVN 32. I have a hunch. The M12 has a @@Am message to manage the satellite ignore list. According to the manual this is a 4-byte (32-bit) field and thus it appears there is no way to set the ignore bit for any satellite with SVN 31. Perhaps not a problem. But it suggests there may be internal 32-bit limitations, yes? Same thing for a Thunderbolt. There are a number of places in the TSIP user manual that talk about 32 SVN (i.e., 0 to 31, or 1 to 32) and no more. A similar 32-bit binary limitation as the M12, perhaps? I wonder if someone at Trimble or ex-Motorola could comment. My rash prediction is that no one is going to see SVN32 with an Oncore VP, M12, Thunderbolt, and maybe a few others. Then again, I wonder if things might magically improve in a week when they set it healthy. Note this is not a operational or performance problem, really. GPSDO did just fine before 32 SV and a receiver overlooking one or two high-numbered SV due a 32-bit receiver limitation isn't going to make a noticeable difference in the performance of a multichannel receiver or GPSDO. Tom My Z3815A sees PRN 32 now albeit as unhealthy. Bruce Right, I concur! Here's my Z3815A output a few minutes ago: Tracking: 7 Not Tracking: 4 PRN El Az C/N PRN El Az 3 46 268 41 6 6 168 9 14 94 4119 33 307 14 29 183 3826 6 33 15 16 41 4332 Not OK 18 62 58 46 21 40 113 45 22 71 259 48 /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.
Re: [time-nuts] GPS PRN vs SV...??
Tom Van Baak wrote: Based on the first 2 lines of http://celestrak.com/NORAD/elements/gps-ops.txt GPS BIIA-10 (PRN 32) 1 20959U 90103A ... It checks out. Thus, you should be looking at: http://www.heavens-above.com/orbitdisplay.asp?Session=kebgcpaanhagkcceebmhgcnbsatid=20959 Tom, you don't have to duck on this pass. :) Cheers, Magnus Good. This new, correct satid also means the ground tracks from heavens-above and from the Trimble Planning program now agree. Thanks, /tvb To have the Trimble Planning program plot PRN32 the health status for PRN 32 in the YUMA almanac has to be edited from 063 to 000. Its best to save it under a different name to avoid later confusion. Also to have the almanac recognised as a yuma almanac by the Trimble Planning program the file extension has to be changed from alm to yum. The yuma file has an alm extension when downloaded from: http://www.navcen.uscg.gov/gps/almanacs.htm Bruce ___ 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 PRN vs SV...??
In message [EMAIL PROTECTED], Magnus Danie lson writes: The 10 SVs which is healthy in the current skyview, yes. I wonder if we would see it in the raw diagnostic dump from the oncores ? There is an undocumented command that spits out tons of internal state at close to full 9600 speed, but I can't remember what it is right now. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] SVN32 and GPS receivers, 32-bit limitations
Tom Van Baak wrote: SatId 20959 GPS SVN32 should now be visible here in Seattle but I have no success seeing it with either a Thunderbolt, an Oncore VP, a Datum 2000, or an M12. True, the satellite is marked unhealthy so it is expected not to see it in the GUI or the timing solution. However, I am also logging raw Motorola binary messages out of the M12, including the @@Ha status message which reports unhealthy as well as healthy satellites, I think. Still no SVN 32. I have a hunch. The M12 has a @@Am message to manage the satellite ignore list. According to the manual this is a 4-byte (32-bit) field and thus it appears there is no way to set the ignore bit for any satellite with SVN 31. Perhaps not a problem. But it suggests there may be internal 32-bit limitations, yes? Same thing for a Thunderbolt. There are a number of places in the TSIP user manual that talk about 32 SVN (i.e., 0 to 31, or 1 to 32) and no more. A similar 32-bit binary limitation as the M12, perhaps? I wonder if someone at Trimble or ex-Motorola could comment. My rash prediction is that no one is going to see SVN32 with an Oncore VP, M12, Thunderbolt, and maybe a few others. Then again, I wonder if things might magically improve in a week when they set it healthy. Note this is not a operational or performance problem, really. GPSDO did just fine before 32 SV and a receiver overlooking one or two high-numbered SV due a 32-bit receiver limitation isn't going to make a noticeable difference in the performance of a multichannel receiver or GPSDO. Tom What about the Trimble Resolution-T? Its TSIP Command packet 0x39 allows for PRN values of 1-32 with 0 used to indicate all satellites. This range for PRN 0, 1-32 is consistent throughout the Resolution T documentation. Bruce ___ 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 PRN 32
On Feb 8, 2008 2:07 PM, Bruce Griffiths [EMAIL PROTECTED] wrote: My Z3815A sees PRN 32 now albeit as unhealthy. My Ublox AEK-4T has an almanac for PRN32, but no ephemeris (duh.) haven't tried my AC12, Lassen iQ, itrax03, gps18/lvc, UT+, GT+ or Jupiter yet... CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ 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 PRN 32
Chris Kuethe wrote: On Feb 8, 2008 2:07 PM, Bruce Griffiths [EMAIL PROTECTED] wrote: My Z3815A sees PRN 32 now albeit as unhealthy. My Ublox AEK-4T has an almanac for PRN32, but no ephemeris (duh.) haven't tried my AC12, Lassen iQ, itrax03, gps18/lvc, UT+, GT+ or Jupiter yet... CK Chris The Jupiter documentation indicates that PRN range is 1-32 with 0 used to indicate all satellites. So you may have some luck with that receiver. Bruce ___ 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 PRN 32
The Jupiter documentation indicates that PRN range is 1-32 with 0 used to indicate all satellites. So you may have some luck with that receiver. Bruce Bruce, An actual test is in order, of course, but speaking as a software engineer, anytime you hear 0 indicates all and 1 to 32 it's a pretty good indicator that a 1-origin, 32-bit, fixed-length array is being used. I'll dig out my Res-t and give it a try.too. Thanks for the suggestion. /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.
Re: [time-nuts] GPS PRN 32
The Novatel Superstar GPS receiver should also be OK for receiving PRN32. The supplied software has provision for monitoring the health of all 32 possible satellites. It also has provision for selectively ignoring any of the 32 possible satellites. Bruce ___ 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 PRN 32
At 07:42 PM 2/9/2008, Bruce Griffiths wrote... The Jupiter documentation indicates that PRN range is 1-32 with 0 used to indicate all satellites. You should be good, then, since the developers obviously accommodated a PRN 32. The statement quoted from the original article (GPS receivers initially were built to accommodate up to 31 satellite signals...) is incorrect. The PRN range for space vehicles has always been 1-32. (see Table 3-I in http://www.navcen.uscg.gov/pubs/gps/icd200/ICD200Cw1234.pdf ). The concern is that the code in some GPS receivers was poorly written, and set up data structures to support PRNs 0-31, even though PRN 0 is, and has always been, undefined. So problems are not a matter of the age of the receiver, but the quality of its programming. ___ 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 PRN vs SV...?? (Bruce Griffiths)
Its TSIP Command packet 0x39 allows for PRN values of 1-32 with 0 used to indicate all satellites. It sure sounds like the sat mask is an unsigned 32-bit mask, sat 1 being bit 0 and so forth. The value 0 being reserved to mean all sats, i.e ~0 for the mask. -ch ___ 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] SVN32 and GPS receivers, 32-bit limitations
PRN32 shows up intermittently when performing a site survey with an iLotus M12M Timing receiver. It's never tracked and does not appear again after a position fix has been achieved. -- kc0ukk at msosborn dot com Cool. What tool or moto binary message did you use to see this? /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.
Re: [time-nuts] SVN32 and GPS receivers, 32-bit limitations
On Sat, 9 Feb 2008 15:21:30 -0800, Tom Van Baak [EMAIL PROTECTED] wrote: My rash prediction is that no one is going to see SVN32 with an Oncore VP, M12, Thunderbolt, and maybe a few others. Then again, I wonder if things might magically improve in a week when they set it healthy. PRN32 shows up intermittently when performing a site survey with an iLotus M12M Timing receiver. It's never tracked and does not appear again after a position fix has been achieved. -- kc0ukk at msosborn dot 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] True Position mystery unit -- ID help
There is a True Position unit at my local surplus yard. Sorry, no photo, but here's the description... True Position 1U, 19 rack space Unpainted steel, no consumer type faceplate TRULMU0307A 0998 Product model # 100,000 - 100,009 10 (or so) SMA connectors, 2 labeled 1PPM and 10MHz may other connectors, phone jack, USB, etc..one labeled GPS. Is this enough to help me find some info online ? ...what/where should I look ? Thanks =Randy= Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ___ 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] SVN32 and GPS receivers, 32-bit limitations
On Sat, 9 Feb 2008 21:13:24 -0800, Tom Van Baak [EMAIL PROTECTED] wrote: PRN32 shows up intermittently when performing a site survey with an iLotus M12M Timing receiver. It's never tracked and does not appear again after a position fix has been achieved. -- kc0ukk at msosborn dot com Cool. What tool or moto binary message did you use to see this? I used Motorola's WinOncore12 ver 1.2 on both 8 and 9 Feb 2008 with the same results. I did save a binary log file on 9 Feb. I intend to do another survey tomorrow night with SynTac (TAC32?) from CNS Systems Version 2.7.4 . -- kc0ukk at msosborn dot 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.
