Re: [time-nuts] time sync by moonbounce
My 2001 copy of Uplink-Downlink was printed by GPO and is 674 pages of 10-point type. I would not want to scan it! Anyway, it was only $25 from an Abebooks seller including tax and shipping and is in near-new condition including a plastic-wrapped dust jacket. Jeremy On Mon, Jun 8, 2020 at 1:01 PM jimlux wrote: > On 6/5/20 3:43 PM, Wannes Sels wrote: > > I bought a used copy of Uplink-Downlink on Ebay. > > Unfortunately the quality is downright bad. Printed on what looks like > > bright white copy paper with a laser printer. > > All the images and illustrations are rasterized, the text is low > > resolution. The photo on the cover shows compression artifacts. > > The pdf on the NASA site is of similar quality, and probably what the > "print to order" version is printed from. > > I don't know where one would go about getting a copy of the GPO printed > version - perhaps a used book dealer. > Conceivably, someone could get a good copy from a library that happens > to have it and spend the time to scan it. > > > > > > > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > > " > > A quick search shows similar experiences with other print on demand books > > from Amazon. > > > > Unfortunately there's no way to tell if a book was printed on demand, > most > > listings just show the cover image instead of a photo of the actual book. > > > > I will try to return it, if I don't have to cover shipping costs. > > > > Buyer beware... > > > > Wannes > > > > On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: > > > >> Hi Jim, > >> > >> This explains a lot of things. As an old time user of the Moon Bounce > >> time synchronization in the Madrid Space Complex, I can say that the > >> system was never popular among the users, it was cumbersome to use and > >> there were already other systems with better accuracy and availability, > >> such as VLBI and Loran-C. We used Loran-C as our daily reference > >> because we had a station at a distance of 650 Km and the signal was very > >> good, even with an old receiver who needed manual estimation of the > >> delay the results were very good. Maybe the aliens who designed the > >> system were not very aware of the humans idiosyncrasies > >> > >> I think that the idea was good, but the implementation was not so good. > >> I can summarize the "peculiarities" as I remember them: > >> > >> - The transmissions had to be scheduled for a period of common moon > >> view. The receiving station was manned 7/24 but the transmitting station > >> (DSS13, if I remember it correctly) had to be manned specially for the > >> event by a crew probably from Barstow, some 40 miles away. > >> > >> - Normally there were not provisions for voice communications between > >> the two end points, so if we did not got correlations we didn't know if > >> the transmitting station was working ok or even if it was not manned due > >> to some problem. > >> > >> - There were not monitoring aids in the receiver, so if we did not have > >> correlations, we has to climb to the roof, verify the pointing of the > >> antenna (there were a rifle scope for that), and if it was, tried to > >> contact DSS13 by phone and pray. > >> > >> - As you can figure it out, the antenna was not remotely controlled. One > >> had to climb to the roof, set the moon declination for that day using a > >> handwheel, slew the hour angle with a switch and select the hour angle > >> rate with another switch. The moon position and rate was obtained from a > >> nautical almanac and when the sky was clear we used the above mentioned > >> rifle scope. > >> > >> The receiver was quite dumb, all intelligence was on the transmitter > >> site. The TX equipment generated a PN code that lasted about 1s, and a > >> full observation cycle lasted about a minute, I don't remember the exact > >> figures. The code was sent advanced to take care of the round trip light > >> time but an additional time bias of 30 us was also introduced which was > >> the basis of the measurement. The bias was decreased 1us/s, so > >> theoretically it was received just on time in the second 30. > >> > >> The receiver generated the same PN using the station timing reference > >> (from a HP 5065A Rb) and it was correlated with the received code. The > >> output of the correlator was integrated and sent to a strip chart > >> recorder. The graph consisted in one trace with a quite noisy ramp and > >> the other trace with 1PPS from the station reference. Now the weird > >> thing: after finishing an observation, we put the graph in a desk and > >> using a drafting rule we draw a straight line that tried to be the "best > >> fit" to the noisy ramp. Were the line crossed the zero we read the PPS > >> mark there and counting back to the start of the minute we got the PPS > >> offset with respect to the transmitting station. Of course we averaged > >> the values obtained from several minutes, after discarding the noisiest > >> ones. > >> > >> Since we
Re: [time-nuts] time sync by moonbounce
I didn't even notice the fold-out. Thanks, Hal! Looks like mine has never been folded out. On Mon, Jun 8, 2020 at 4:49 PM Hal Murray wrote: > > Abe Books has several copies of the hardcopy. > https://www.abebooks.com/ > $30. Check the fine print. At least one says print on demand. > > My copy is in near perfect condition. Page 127/8 is a 3 page fold out > diagram. > > It's 650 pages, way more than I will ever read, but if somebody sends a > note > with a page number, I'll probably look it up. > > It's also the sort of thing that I can easily get sucked into. Just open > to a > random page and start reading. For example, page 525 is Orbiting VLBI, > clearly time-nuts bait. > > > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > > " A quick search shows similar experiences with other print on demand > books > > from Amazon. > > Print on Demand doesn't have to be crap quality. > > A friend wrote a college level physics text. The story he told was that > the > college book store would put in an order with the publisher. The > publisher > would send it to the nearest Fed-Ex print shop. (I forget what they were > called back then.) They would print and deliver the next day. > > Xerographic printers can be really good. > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
Abe Books has several copies of the hardcopy. https://www.abebooks.com/ $30. Check the fine print. At least one says print on demand. My copy is in near perfect condition. Page 127/8 is a 3 page fold out diagram. It's 650 pages, way more than I will ever read, but if somebody sends a note with a page number, I'll probably look it up. It's also the sort of thing that I can easily get sucked into. Just open to a random page and start reading. For example, page 525 is Orbiting VLBI, clearly time-nuts bait. > The last page reveals the culprit: "Printed in Great Britain by Amazon.co.uk > " A quick search shows similar experiences with other print on demand books > from Amazon. Print on Demand doesn't have to be crap quality. A friend wrote a college level physics text. The story he told was that the college book store would put in an order with the publisher. The publisher would send it to the nearest Fed-Ex print shop. (I forget what they were called back then.) They would print and deliver the next day. Xerographic printers can be really good. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
My copy is an original, bought from one of the Abebooks sellers. It’s a huge book and the type is on the small side; I’m still working my way through the Introduction. Looks like a lot of good information. Jeremy On Mon, Jun 8, 2020 at 5:23 AM Wannes Sels wrote: > I bought a used copy of Uplink-Downlink on Ebay. > Unfortunately the quality is downright bad. Printed on what looks like > bright white copy paper with a laser printer. > All the images and illustrations are rasterized, the text is low > resolution. The photo on the cover shows compression artifacts. > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > " > A quick search shows similar experiences with other print on demand books > from Amazon. > > Unfortunately there's no way to tell if a book was printed on demand, most > listings just show the cover image instead of a photo of the actual book. > > I will try to return it, if I don't have to cover shipping costs. > > Buyer beware... > > Wannes > > On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: > > > Hi Jim, > > > > This explains a lot of things. As an old time user of the Moon Bounce > > time synchronization in the Madrid Space Complex, I can say that the > > system was never popular among the users, it was cumbersome to use and > > there were already other systems with better accuracy and availability, > > such as VLBI and Loran-C. We used Loran-C as our daily reference > > because we had a station at a distance of 650 Km and the signal was very > > good, even with an old receiver who needed manual estimation of the > > delay the results were very good. Maybe the aliens who designed the > > system were not very aware of the humans idiosyncrasies > > > > I think that the idea was good, but the implementation was not so good. > > I can summarize the "peculiarities" as I remember them: > > > > - The transmissions had to be scheduled for a period of common moon > > view. The receiving station was manned 7/24 but the transmitting station > > (DSS13, if I remember it correctly) had to be manned specially for the > > event by a crew probably from Barstow, some 40 miles away. > > > > - Normally there were not provisions for voice communications between > > the two end points, so if we did not got correlations we didn't know if > > the transmitting station was working ok or even if it was not manned due > > to some problem. > > > > - There were not monitoring aids in the receiver, so if we did not have > > correlations, we has to climb to the roof, verify the pointing of the > > antenna (there were a rifle scope for that), and if it was, tried to > > contact DSS13 by phone and pray. > > > > - As you can figure it out, the antenna was not remotely controlled. One > > had to climb to the roof, set the moon declination for that day using a > > handwheel, slew the hour angle with a switch and select the hour angle > > rate with another switch. The moon position and rate was obtained from a > > nautical almanac and when the sky was clear we used the above mentioned > > rifle scope. > > > > The receiver was quite dumb, all intelligence was on the transmitter > > site. The TX equipment generated a PN code that lasted about 1s, and a > > full observation cycle lasted about a minute, I don't remember the exact > > figures. The code was sent advanced to take care of the round trip light > > time but an additional time bias of 30 us was also introduced which was > > the basis of the measurement. The bias was decreased 1us/s, so > > theoretically it was received just on time in the second 30. > > > > The receiver generated the same PN using the station timing reference > > (from a HP 5065A Rb) and it was correlated with the received code. The > > output of the correlator was integrated and sent to a strip chart > > recorder. The graph consisted in one trace with a quite noisy ramp and > > the other trace with 1PPS from the station reference. Now the weird > > thing: after finishing an observation, we put the graph in a desk and > > using a drafting rule we draw a straight line that tried to be the "best > > fit" to the noisy ramp. Were the line crossed the zero we read the PPS > > mark there and counting back to the start of the minute we got the PPS > > offset with respect to the transmitting station. Of course we averaged > > the values obtained from several minutes, after discarding the noisiest > > ones. > > > > Since we didn't had any faith in the system we didn't tried to suggest > > improvements or improve it ourselves. A good one could be to use a > > computer program to perform the best fit analytically, but this would > > mean to type the hundreds of points manually from the graph and we never > > tried this. There were not a digital version of the output, we also > > could use a digital voltmeter for acquiring it. We suggested or > > implemented a lot of improvements to other operational things, but this > > contraption was felt as a dead horse from the
Re: [time-nuts] time sync by moonbounce
On 6/5/20 3:43 PM, Wannes Sels wrote: I bought a used copy of Uplink-Downlink on Ebay. Unfortunately the quality is downright bad. Printed on what looks like bright white copy paper with a laser printer. All the images and illustrations are rasterized, the text is low resolution. The photo on the cover shows compression artifacts. The pdf on the NASA site is of similar quality, and probably what the "print to order" version is printed from. I don't know where one would go about getting a copy of the GPO printed version - perhaps a used book dealer. Conceivably, someone could get a good copy from a library that happens to have it and spend the time to scan it. The last page reveals the culprit: "Printed in Great Britain by Amazon.co.uk " A quick search shows similar experiences with other print on demand books from Amazon. Unfortunately there's no way to tell if a book was printed on demand, most listings just show the cover image instead of a photo of the actual book. I will try to return it, if I don't have to cover shipping costs. Buyer beware... Wannes On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: Hi Jim, This explains a lot of things. As an old time user of the Moon Bounce time synchronization in the Madrid Space Complex, I can say that the system was never popular among the users, it was cumbersome to use and there were already other systems with better accuracy and availability, such as VLBI and Loran-C. We used Loran-C as our daily reference because we had a station at a distance of 650 Km and the signal was very good, even with an old receiver who needed manual estimation of the delay the results were very good. Maybe the aliens who designed the system were not very aware of the humans idiosyncrasies I think that the idea was good, but the implementation was not so good. I can summarize the "peculiarities" as I remember them: - The transmissions had to be scheduled for a period of common moon view. The receiving station was manned 7/24 but the transmitting station (DSS13, if I remember it correctly) had to be manned specially for the event by a crew probably from Barstow, some 40 miles away. - Normally there were not provisions for voice communications between the two end points, so if we did not got correlations we didn't know if the transmitting station was working ok or even if it was not manned due to some problem. - There were not monitoring aids in the receiver, so if we did not have correlations, we has to climb to the roof, verify the pointing of the antenna (there were a rifle scope for that), and if it was, tried to contact DSS13 by phone and pray. - As you can figure it out, the antenna was not remotely controlled. One had to climb to the roof, set the moon declination for that day using a handwheel, slew the hour angle with a switch and select the hour angle rate with another switch. The moon position and rate was obtained from a nautical almanac and when the sky was clear we used the above mentioned rifle scope. The receiver was quite dumb, all intelligence was on the transmitter site. The TX equipment generated a PN code that lasted about 1s, and a full observation cycle lasted about a minute, I don't remember the exact figures. The code was sent advanced to take care of the round trip light time but an additional time bias of 30 us was also introduced which was the basis of the measurement. The bias was decreased 1us/s, so theoretically it was received just on time in the second 30. The receiver generated the same PN using the station timing reference (from a HP 5065A Rb) and it was correlated with the received code. The output of the correlator was integrated and sent to a strip chart recorder. The graph consisted in one trace with a quite noisy ramp and the other trace with 1PPS from the station reference. Now the weird thing: after finishing an observation, we put the graph in a desk and using a drafting rule we draw a straight line that tried to be the "best fit" to the noisy ramp. Were the line crossed the zero we read the PPS mark there and counting back to the start of the minute we got the PPS offset with respect to the transmitting station. Of course we averaged the values obtained from several minutes, after discarding the noisiest ones. Since we didn't had any faith in the system we didn't tried to suggest improvements or improve it ourselves. A good one could be to use a computer program to perform the best fit analytically, but this would mean to type the hundreds of points manually from the graph and we never tried this. There were not a digital version of the output, we also could use a digital voltmeter for acquiring it. We suggested or implemented a lot of improvements to other operational things, but this contraption was felt as a dead horse from the beginning and its operational life was short. Later it was replaced with a GPS based one: 2 full height racks filled with equipment and an antenna made from a 10 or 20 gallon
Re: [time-nuts] time sync by moonbounce
I also bought my copy of "Uplink-Downlink" through Amazon but had better luck. The cover photo is in color, not quite as sharp as I would have preferred but has no apparent compression artifacts. The text inside is of good quality- nop complaints in this department. However, the photos inside are of poor quality. They are screen-printed, with the screen elements as big as basketballs, and in general any text within the photo-proper is completely unreadable. But the captions are just fine. I've been unable to find any publisher's info, just a note on the back dustcover stating "Made in the USA; Coppell, TX; 30 May 2020". It arrived at my home in Kerrville, TX three days later, so I presume that the copy was custom printed just for me. Dana On Mon, Jun 8, 2020 at 7:23 AM Wannes Sels wrote: > I bought a used copy of Uplink-Downlink on Ebay. > Unfortunately the quality is downright bad. Printed on what looks like > bright white copy paper with a laser printer. > All the images and illustrations are rasterized, the text is low > resolution. The photo on the cover shows compression artifacts. > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > " > A quick search shows similar experiences with other print on demand books > from Amazon. > > Unfortunately there's no way to tell if a book was printed on demand, most > listings just show the cover image instead of a photo of the actual book. > > I will try to return it, if I don't have to cover shipping costs. > > Buyer beware... > > Wannes > > On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: > > > Hi Jim, > > > > This explains a lot of things. As an old time user of the Moon Bounce > > time synchronization in the Madrid Space Complex, I can say that the > > system was never popular among the users, it was cumbersome to use and > > there were already other systems with better accuracy and availability, > > such as VLBI and Loran-C. We used Loran-C as our daily reference > > because we had a station at a distance of 650 Km and the signal was very > > good, even with an old receiver who needed manual estimation of the > > delay the results were very good. Maybe the aliens who designed the > > system were not very aware of the humans idiosyncrasies > > > > I think that the idea was good, but the implementation was not so good. > > I can summarize the "peculiarities" as I remember them: > > > > - The transmissions had to be scheduled for a period of common moon > > view. The receiving station was manned 7/24 but the transmitting station > > (DSS13, if I remember it correctly) had to be manned specially for the > > event by a crew probably from Barstow, some 40 miles away. > > > > - Normally there were not provisions for voice communications between > > the two end points, so if we did not got correlations we didn't know if > > the transmitting station was working ok or even if it was not manned due > > to some problem. > > > > - There were not monitoring aids in the receiver, so if we did not have > > correlations, we has to climb to the roof, verify the pointing of the > > antenna (there were a rifle scope for that), and if it was, tried to > > contact DSS13 by phone and pray. > > > > - As you can figure it out, the antenna was not remotely controlled. One > > had to climb to the roof, set the moon declination for that day using a > > handwheel, slew the hour angle with a switch and select the hour angle > > rate with another switch. The moon position and rate was obtained from a > > nautical almanac and when the sky was clear we used the above mentioned > > rifle scope. > > > > The receiver was quite dumb, all intelligence was on the transmitter > > site. The TX equipment generated a PN code that lasted about 1s, and a > > full observation cycle lasted about a minute, I don't remember the exact > > figures. The code was sent advanced to take care of the round trip light > > time but an additional time bias of 30 us was also introduced which was > > the basis of the measurement. The bias was decreased 1us/s, so > > theoretically it was received just on time in the second 30. > > > > The receiver generated the same PN using the station timing reference > > (from a HP 5065A Rb) and it was correlated with the received code. The > > output of the correlator was integrated and sent to a strip chart > > recorder. The graph consisted in one trace with a quite noisy ramp and > > the other trace with 1PPS from the station reference. Now the weird > > thing: after finishing an observation, we put the graph in a desk and > > using a drafting rule we draw a straight line that tried to be the "best > > fit" to the noisy ramp. Were the line crossed the zero we read the PPS > > mark there and counting back to the start of the minute we got the PPS > > offset with respect to the transmitting station. Of course we averaged > > the values obtained from several minutes, after discarding the noisiest > > ones. > > > > Since we didn't had any
Re: [time-nuts] time sync by moonbounce
Many thanks Wannes for the warning Jean-Louis Le 06/06/2020 à 00:43, Wannes Sels a écrit : I bought a used copy of Uplink-Downlink on Ebay. Unfortunately the quality is downright bad. Printed on what looks like bright white copy paper with a laser printer. All the images and illustrations are rasterized, the text is low resolution. The photo on the cover shows compression artifacts. The last page reveals the culprit: "Printed in Great Britain by Amazon.co.uk " A quick search shows similar experiences with other print on demand books from Amazon. Unfortunately there's no way to tell if a book was printed on demand, most listings just show the cover image instead of a photo of the actual book. I will try to return it, if I don't have to cover shipping costs. Buyer beware... Wannes On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: Hi Jim, This explains a lot of things. As an old time user of the Moon Bounce time synchronization in the Madrid Space Complex, I can say that the system was never popular among the users, it was cumbersome to use and there were already other systems with better accuracy and availability, such as VLBI and Loran-C. We used Loran-C as our daily reference because we had a station at a distance of 650 Km and the signal was very good, even with an old receiver who needed manual estimation of the delay the results were very good. Maybe the aliens who designed the system were not very aware of the humans idiosyncrasies I think that the idea was good, but the implementation was not so good. I can summarize the "peculiarities" as I remember them: - The transmissions had to be scheduled for a period of common moon view. The receiving station was manned 7/24 but the transmitting station (DSS13, if I remember it correctly) had to be manned specially for the event by a crew probably from Barstow, some 40 miles away. - Normally there were not provisions for voice communications between the two end points, so if we did not got correlations we didn't know if the transmitting station was working ok or even if it was not manned due to some problem. - There were not monitoring aids in the receiver, so if we did not have correlations, we has to climb to the roof, verify the pointing of the antenna (there were a rifle scope for that), and if it was, tried to contact DSS13 by phone and pray. - As you can figure it out, the antenna was not remotely controlled. One had to climb to the roof, set the moon declination for that day using a handwheel, slew the hour angle with a switch and select the hour angle rate with another switch. The moon position and rate was obtained from a nautical almanac and when the sky was clear we used the above mentioned rifle scope. The receiver was quite dumb, all intelligence was on the transmitter site. The TX equipment generated a PN code that lasted about 1s, and a full observation cycle lasted about a minute, I don't remember the exact figures. The code was sent advanced to take care of the round trip light time but an additional time bias of 30 us was also introduced which was the basis of the measurement. The bias was decreased 1us/s, so theoretically it was received just on time in the second 30. The receiver generated the same PN using the station timing reference (from a HP 5065A Rb) and it was correlated with the received code. The output of the correlator was integrated and sent to a strip chart recorder. The graph consisted in one trace with a quite noisy ramp and the other trace with 1PPS from the station reference. Now the weird thing: after finishing an observation, we put the graph in a desk and using a drafting rule we draw a straight line that tried to be the "best fit" to the noisy ramp. Were the line crossed the zero we read the PPS mark there and counting back to the start of the minute we got the PPS offset with respect to the transmitting station. Of course we averaged the values obtained from several minutes, after discarding the noisiest ones. Since we didn't had any faith in the system we didn't tried to suggest improvements or improve it ourselves. A good one could be to use a computer program to perform the best fit analytically, but this would mean to type the hundreds of points manually from the graph and we never tried this. There were not a digital version of the output, we also could use a digital voltmeter for acquiring it. We suggested or implemented a lot of improvements to other operational things, but this contraption was felt as a dead horse from the beginning and its operational life was short. Later it was replaced with a GPS based one: 2 full height racks filled with equipment and an antenna made from a 10 or 20 gallon hermetic paint drum for housing the front end electronics, topped with a fiberglass radome about 1 1/2 ' in diameter. It was painted white, but the cylinder origin was discovered during a maintenance. It was a beautiful prototype that worked very well during its shot life. I don't keep pictures
Re: [time-nuts] time sync by moonbounce
I bought a used copy of Uplink-Downlink on Ebay. Unfortunately the quality is downright bad. Printed on what looks like bright white copy paper with a laser printer. All the images and illustrations are rasterized, the text is low resolution. The photo on the cover shows compression artifacts. The last page reveals the culprit: "Printed in Great Britain by Amazon.co.uk " A quick search shows similar experiences with other print on demand books from Amazon. Unfortunately there's no way to tell if a book was printed on demand, most listings just show the cover image instead of a photo of the actual book. I will try to return it, if I don't have to cover shipping costs. Buyer beware... Wannes On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: > Hi Jim, > > This explains a lot of things. As an old time user of the Moon Bounce > time synchronization in the Madrid Space Complex, I can say that the > system was never popular among the users, it was cumbersome to use and > there were already other systems with better accuracy and availability, > such as VLBI and Loran-C. We used Loran-C as our daily reference > because we had a station at a distance of 650 Km and the signal was very > good, even with an old receiver who needed manual estimation of the > delay the results were very good. Maybe the aliens who designed the > system were not very aware of the humans idiosyncrasies > > I think that the idea was good, but the implementation was not so good. > I can summarize the "peculiarities" as I remember them: > > - The transmissions had to be scheduled for a period of common moon > view. The receiving station was manned 7/24 but the transmitting station > (DSS13, if I remember it correctly) had to be manned specially for the > event by a crew probably from Barstow, some 40 miles away. > > - Normally there were not provisions for voice communications between > the two end points, so if we did not got correlations we didn't know if > the transmitting station was working ok or even if it was not manned due > to some problem. > > - There were not monitoring aids in the receiver, so if we did not have > correlations, we has to climb to the roof, verify the pointing of the > antenna (there were a rifle scope for that), and if it was, tried to > contact DSS13 by phone and pray. > > - As you can figure it out, the antenna was not remotely controlled. One > had to climb to the roof, set the moon declination for that day using a > handwheel, slew the hour angle with a switch and select the hour angle > rate with another switch. The moon position and rate was obtained from a > nautical almanac and when the sky was clear we used the above mentioned > rifle scope. > > The receiver was quite dumb, all intelligence was on the transmitter > site. The TX equipment generated a PN code that lasted about 1s, and a > full observation cycle lasted about a minute, I don't remember the exact > figures. The code was sent advanced to take care of the round trip light > time but an additional time bias of 30 us was also introduced which was > the basis of the measurement. The bias was decreased 1us/s, so > theoretically it was received just on time in the second 30. > > The receiver generated the same PN using the station timing reference > (from a HP 5065A Rb) and it was correlated with the received code. The > output of the correlator was integrated and sent to a strip chart > recorder. The graph consisted in one trace with a quite noisy ramp and > the other trace with 1PPS from the station reference. Now the weird > thing: after finishing an observation, we put the graph in a desk and > using a drafting rule we draw a straight line that tried to be the "best > fit" to the noisy ramp. Were the line crossed the zero we read the PPS > mark there and counting back to the start of the minute we got the PPS > offset with respect to the transmitting station. Of course we averaged > the values obtained from several minutes, after discarding the noisiest > ones. > > Since we didn't had any faith in the system we didn't tried to suggest > improvements or improve it ourselves. A good one could be to use a > computer program to perform the best fit analytically, but this would > mean to type the hundreds of points manually from the graph and we never > tried this. There were not a digital version of the output, we also > could use a digital voltmeter for acquiring it. We suggested or > implemented a lot of improvements to other operational things, but this > contraption was felt as a dead horse from the beginning and its > operational life was short. Later it was replaced with a GPS based one: > 2 full height racks filled with equipment and an antenna made from a 10 > or 20 gallon hermetic paint drum for housing the front end electronics, > topped with a fiberglass radome about 1 1/2 ' in diameter. It was > painted white, but the cylinder origin was discovered during a > maintenance. It was a beautiful prototype that worked very well during >
Re: [time-nuts] time sync by moonbounce
Hi Jim, This explains a lot of things. As an old time user of the Moon Bounce time synchronization in the Madrid Space Complex, I can say that the system was never popular among the users, it was cumbersome to use and there were already other systems with better accuracy and availability, such as VLBI and Loran-C. We used Loran-C as our daily reference because we had a station at a distance of 650 Km and the signal was very good, even with an old receiver who needed manual estimation of the delay the results were very good. Maybe the aliens who designed the system were not very aware of the humans idiosyncrasies I think that the idea was good, but the implementation was not so good. I can summarize the "peculiarities" as I remember them: - The transmissions had to be scheduled for a period of common moon view. The receiving station was manned 7/24 but the transmitting station (DSS13, if I remember it correctly) had to be manned specially for the event by a crew probably from Barstow, some 40 miles away. - Normally there were not provisions for voice communications between the two end points, so if we did not got correlations we didn't know if the transmitting station was working ok or even if it was not manned due to some problem. - There were not monitoring aids in the receiver, so if we did not have correlations, we has to climb to the roof, verify the pointing of the antenna (there were a rifle scope for that), and if it was, tried to contact DSS13 by phone and pray. - As you can figure it out, the antenna was not remotely controlled. One had to climb to the roof, set the moon declination for that day using a handwheel, slew the hour angle with a switch and select the hour angle rate with another switch. The moon position and rate was obtained from a nautical almanac and when the sky was clear we used the above mentioned rifle scope. The receiver was quite dumb, all intelligence was on the transmitter site. The TX equipment generated a PN code that lasted about 1s, and a full observation cycle lasted about a minute, I don't remember the exact figures. The code was sent advanced to take care of the round trip light time but an additional time bias of 30 us was also introduced which was the basis of the measurement. The bias was decreased 1us/s, so theoretically it was received just on time in the second 30. The receiver generated the same PN using the station timing reference (from a HP 5065A Rb) and it was correlated with the received code. The output of the correlator was integrated and sent to a strip chart recorder. The graph consisted in one trace with a quite noisy ramp and the other trace with 1PPS from the station reference. Now the weird thing: after finishing an observation, we put the graph in a desk and using a drafting rule we draw a straight line that tried to be the "best fit" to the noisy ramp. Were the line crossed the zero we read the PPS mark there and counting back to the start of the minute we got the PPS offset with respect to the transmitting station. Of course we averaged the values obtained from several minutes, after discarding the noisiest ones. Since we didn't had any faith in the system we didn't tried to suggest improvements or improve it ourselves. A good one could be to use a computer program to perform the best fit analytically, but this would mean to type the hundreds of points manually from the graph and we never tried this. There were not a digital version of the output, we also could use a digital voltmeter for acquiring it. We suggested or implemented a lot of improvements to other operational things, but this contraption was felt as a dead horse from the beginning and its operational life was short. Later it was replaced with a GPS based one: 2 full height racks filled with equipment and an antenna made from a 10 or 20 gallon hermetic paint drum for housing the front end electronics, topped with a fiberglass radome about 1 1/2 ' in diameter. It was painted white, but the cylinder origin was discovered during a maintenance. It was a beautiful prototype that worked very well during its shot life. I don't keep pictures of this equipment, but I have one with the same antenna used for other purposes. Sorry for the bandwidth, but the thread brought me old memories. Best regards, Ignacio El 23/05/2020 a las 19:17, jimlux escribió: On 5/23/20 9:18 AM, Mike Millen wrote: Probably a good idea... there are two page 19s and no page 20 in the pdf. :-( That's the page where the aliens came and told us how to build the DSN, then the story resumes with 26m antenna design and operation. (If anyone's interested, I can probably ask the librarians to find it at JPL - correcting the pdf/microfilm is probably beyond scope) -- El software de antivirus Avast ha analizado este correo electrónico en busca de virus. https://www.avast.com/antivirus
Re: [time-nuts] time sync by moonbounce
That’s it! And Author Mudgway turns out to be from Sonoma, a town in my county just a few miles east of me. I wonder if I can get him to sign my copy when it comes out? On Sat, May 23, 2020 at 3:52 PM Adam Kumiszcza wrote: > I think this is available here: > https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020033033.pdf and > here: > > https://books.google.pl/books?id=vn5TMAAJ=frontcover=pl=gbs_ge_summary_r=0#v=onepage=false > > Best regards, > Adam Kumiszcza > > On Sat, May 23, 2020 at 5:20 PM Jeremy Nichols wrote: > > > Sufficiently interesting that I bought a paper copy through Abebooks. > Looks > > like a somewhat later version, author given as Douglas Mudgway, title > > “ Uplink-Downlink: > > A History of the Deep Space Network 1957-1997.” “Oversized,” 674 > > pages. Abebooks > > lists a couple dozen copies in both hardback and paperback at prices from > > reasonable to ridiculous, as is usual for bookstores. > > > > Jeremy > > > > > > On Sat, May 23, 2020 at 3:47 AM ew via time-nuts < > time-nuts@lists.febo.com > > > > > wrote: > > > > > This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did > > > learn a lot at the same time fascinating > > > Bert Kehren > > > In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, > > > jim...@earthlink.net writes: > > > > > > Apparently, they used moonbounce between DSN stations to synchronize > to 5 > > > microseconds in 1968. It was easier and cheaper than flying cesium > clocks > > > around. (And the Rb standards weren't good enough). > > > https://ntrs.nasa.gov/search.jsp?R=19770007245 > > > History of DSN - mostly about politics, history, transmitters and > > > receivers, but a whole section on timekeeping, phase measurements, etc. > > > starting around page 133 (The DSN Inherent accuracy project), and the > > > discovery during Mariner that UTC and UTI were different enough to > cause > > > nav errors. > > > ___time-nuts mailing list > -- > > > time-n...@lists.febo.comTo unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand > > follow > > > the instructions there. > > > ___ > > > time-nuts mailing list -- time-nuts@lists.febo.com > > > To unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > > and follow the instructions there. > > > > > -- > > Jeremy Nichols > > Sent from my iPad 6. > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
I think this is available here: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020033033.pdf and here: https://books.google.pl/books?id=vn5TMAAJ=frontcover=pl=gbs_ge_summary_r=0#v=onepage=false Best regards, Adam Kumiszcza On Sat, May 23, 2020 at 5:20 PM Jeremy Nichols wrote: > Sufficiently interesting that I bought a paper copy through Abebooks. Looks > like a somewhat later version, author given as Douglas Mudgway, title > “ Uplink-Downlink: > A History of the Deep Space Network 1957-1997.” “Oversized,” 674 > pages. Abebooks > lists a couple dozen copies in both hardback and paperback at prices from > reasonable to ridiculous, as is usual for bookstores. > > Jeremy > > > On Sat, May 23, 2020 at 3:47 AM ew via time-nuts > > wrote: > > > This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did > > learn a lot at the same time fascinating > > Bert Kehren > > In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, > > jim...@earthlink.net writes: > > > > Apparently, they used moonbounce between DSN stations to synchronize to 5 > > microseconds in 1968. It was easier and cheaper than flying cesium clocks > > around. (And the Rb standards weren't good enough). > > https://ntrs.nasa.gov/search.jsp?R=19770007245 > > History of DSN - mostly about politics, history, transmitters and > > receivers, but a whole section on timekeeping, phase measurements, etc. > > starting around page 133 (The DSN Inherent accuracy project), and the > > discovery during Mariner that UTC and UTI were different enough to cause > > nav errors. > > ___time-nuts mailing list -- > > time-n...@lists.febo.comTo unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand > follow > > the instructions there. > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > -- > Jeremy Nichols > Sent from my iPad 6. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
On 5/23/20 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy A good read (there's a morning for you)... Not much technical detail in the book (it's a history, not a textbook), but there are good references. An interesting comment in the early part about why there's not a good set of documents to refer to. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
On 5/23/20 9:18 AM, Mike Millen wrote: Probably a good idea... there are two page 19s and no page 20 in the pdf. :-( That's the page where the aliens came and told us how to build the DSN, then the story resumes with 26m antenna design and operation. (If anyone's interested, I can probably ask the librarians to find it at JPL - correcting the pdf/microfilm is probably beyond scope) Mike - M0MLM On 23/05/2020 17:12, Wes wrote: You talked me in to it. Wes N7WS On 5/23/2020 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
On 5/23/20 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Different author (The report I pointed to is by William Corliss), but perhaps the same source material, (at least up to 1975) it's available as a downloadable pdf, theoretically (although the link is to the cover page only) - I'll talk to the site owner and get that fixed. https://descanso.jpl.nasa.gov/history/dsnHistory.html (there's a version here: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020033033.pdf) The second link on the dsnhistory page, to a list of references, is something you might find interesting. There's a set of books published by JPL at https://descanso.jpl.nasa.gov/ Various series.. Some are not particularly time-nutty, but some are - I'd look for things on radiometric tracking and nav. Here's a whole series on it: https://descanso.jpl.nasa.gov/evolution/evolution.html - not much technical detail in the paper, more a history of what was done when, but the papers in the references might be useful. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
Probably a good idea... there are two page 19s and no page 20 in the pdf. :-( Mike - M0MLM On 23/05/2020 17:12, Wes wrote: You talked me in to it. Wes N7WS On 5/23/2020 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
You talked me in to it. Wes N7WS On 5/23/2020 8:19 AM, Jeremy Nichols wrote: Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy On Sat, May 23, 2020 at 3:47 AM ew via time-nuts wrote: This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did learn a lot at the same time fascinating Bert Kehren In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, jim...@earthlink.net writes: Apparently, they used moonbounce between DSN stations to synchronize to 5 microseconds in 1968. It was easier and cheaper than flying cesium clocks around. (And the Rb standards weren't good enough). https://ntrs.nasa.gov/search.jsp?R=19770007245 History of DSN - mostly about politics, history, transmitters and receivers, but a whole section on timekeeping, phase measurements, etc. starting around page 133 (The DSN Inherent accuracy project), and the discovery during Mariner that UTC and UTI were different enough to cause nav errors. ___time-nuts mailing list -- time-n...@lists.febo.comTo unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy On Sat, May 23, 2020 at 3:47 AM ew via time-nuts wrote: > This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did > learn a lot at the same time fascinating > Bert Kehren > In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, > jim...@earthlink.net writes: > > Apparently, they used moonbounce between DSN stations to synchronize to 5 > microseconds in 1968. It was easier and cheaper than flying cesium clocks > around. (And the Rb standards weren't good enough). > https://ntrs.nasa.gov/search.jsp?R=19770007245 > History of DSN - mostly about politics, history, transmitters and > receivers, but a whole section on timekeeping, phase measurements, etc. > starting around page 133 (The DSN Inherent accuracy project), and the > discovery during Mariner that UTC and UTI were different enough to cause > nav errors. > ___time-nuts mailing list -- > time-n...@lists.febo.comTo unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow > the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] time sync by moonbounce
This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did learn a lot at the same time fascinating Bert Kehren In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, jim...@earthlink.net writes: Apparently, they used moonbounce between DSN stations to synchronize to 5 microseconds in 1968. It was easier and cheaper than flying cesium clocks around. (And the Rb standards weren't good enough). https://ntrs.nasa.gov/search.jsp?R=19770007245 History of DSN - mostly about politics, history, transmitters and receivers, but a whole section on timekeeping, phase measurements, etc. starting around page 133 (The DSN Inherent accuracy project), and the discovery during Mariner that UTC and UTI were different enough to cause nav errors. ___time-nuts mailing list -- time-n...@lists.febo.comTo unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] time sync by moonbounce
Apparently, they used moonbounce between DSN stations to synchronize to 5 microseconds in 1968. It was easier and cheaper than flying cesium clocks around. (And the Rb standards weren't good enough). https://ntrs.nasa.gov/search.jsp?R=19770007245 History of DSN - mostly about politics, history, transmitters and receivers, but a whole section on timekeeping, phase measurements, etc. starting around page 133 (The DSN Inherent accuracy project), and the discovery during Mariner that UTC and UTI were different enough to cause nav errors. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
