[amsat-bb] ISS - Mission Control Comm Check
Today's ISS crew schedule shows VHF comm checks from the Russian segment while over North America. Ground stations are at White Sands and Wallops. The pass is from 20:00 UTC (west coast) to 20:15 UTC (east coast). VHF-1 is 143.625 MHz FM, there may also be something on VHF-2 at 130.167 MHz. Bob Christy ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] tisat-1
Hi Amsaters Can someone send me the keps or the satellite id number for Tisat-1 Thanks nick Office 337 593 8700 Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: tisat-1
Hi Nick, It will be one of the constellation 36795 to 36801 - they all seem to be fairly close together still. I listened for both Tisat and Studsat last evening but didn't hear anything so I am wondering if anyone has had recent success? 73 GrahamG3VZV --- On Wed, 14/7/10, Nick Pugh K5QXJ wrote: From: Nick Pugh K5QXJ Subject: [amsat-bb] tisat-1 To: amsat-bb@amsat.org Date: Wednesday, 14 July, 2010, 10:52 Hi Amsaters Can someone send me the keps or the satellite id number for Tisat-1 Thanks nick Office 337 593 8700 Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: tisat-1
Thanks Graham I will listen to you conference at the end of the week nick From: GRAHAM SHIRVILLE [mailto:g.shirvi...@btinternet.com] Sent: Wednesday, July 14, 2010 6:07 AM To: amsat-bb@amsat.org; Nick Pugh K5QXJ Subject: Re: [amsat-bb] tisat-1 Hi Nick, It will be one of the constellation 36795 to 36801 - they all seem to be fairly close together still. I listened for both Tisat and Studsat last evening but didn't hear anything so I am wondering if anyone has had recent success? 73 Graham G3VZV --- On Wed, 14/7/10, Nick Pugh K5QXJ wrote: From: Nick Pugh K5QXJ Subject: [amsat-bb] tisat-1 To: amsat-bb@amsat.org Date: Wednesday, 14 July, 2010, 10:52 Hi Amsaters Can someone send me the keps or the satellite id number for Tisat-1 Thanks nick Office 337 593 8700 Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: ISS - Mission Control Comm Check
Note: When the VHF-1 transmitter is Running, the Amateur Radio receivers in the 2-meter band will go deaf (Receiving on 145, 490, 145.200, 145.990). This is because the Transmitting antenna for VHF-1 is less than 50 feet away from the Amateur Radio antennas. The VHF-1 transmitter is usually left running for a few hours at a time for ground stations to test against. If you wish to test this theory, just try to ping the Amateur radio packet station ISS during a VHF-1 transmitter test. When VHF-1 is transmitting, you will not see any packet activity, other than internally generated Beacons on 145.800 (down 145.800, uplink 145.990). When VHF-1 shuts down, normal packet access will resume. Marex discovered this problem with the Mir Amateur Radio station. We then custom designed a filter by DCI, to resolve the issues. No such filter exists on ISS. http://www.marexmg.org/documents/DCIFilterProject1.doc WF1F, www.marexmg.org --- On Wed, 7/14/10, Bob Christy wrote: > From: Bob Christy > Subject: [amsat-bb] ISS - Mission Control Comm Check > To: amsat-bb@amsat.org > Date: Wednesday, July 14, 2010, 4:47 AM > Today's ISS crew schedule shows VHF > comm checks from the Russian segment while over North > America. Ground stations are at White Sands and Wallops. > > The pass is from 20:00 UTC (west coast) to 20:15 UTC (east > coast). > > VHF-1 is 143.625 MHz FM, there may also be something on > VHF-2 at 130.167 MHz. > > Bob Christy > ___ > Sent via amsat...@amsat.org. > Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur > satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: ISS - Mission Control Comm Check
A couple of corrections to Miles' post. Packet is on 145.825 simplex. VHF-1 does de-sense the D700 radio but not completely (I have see a station break through) but it takes a big gun to do so. The VHF-1 transmitter is only planned to be keyed when in range of the US ground stations as indicated by the crew timeline (10-20 minutes depending on the orbit and number of ground stations in the footprint). Kenneth - N5VHO -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of MM Sent: Wednesday, July 14, 2010 7:29 AM To: amsat-bb@amsat.org; Bob Christy Subject: [amsat-bb] Re: ISS - Mission Control Comm Check Note: When the VHF-1 transmitter is Running, the Amateur Radio receivers in the 2-meter band will go deaf (Receiving on 145, 490, 145.200, 145.990). This is because the Transmitting antenna for VHF-1 is less than 50 feet away from the Amateur Radio antennas. The VHF-1 transmitter is usually left running for a few hours at a time for ground stations to test against. If you wish to test this theory, just try to ping the Amateur radio packet station ISS during a VHF-1 transmitter test. When VHF-1 is transmitting, you will not see any packet activity, other than internally generated Beacons on 145.800 (down 145.800, uplink 145.990). When VHF-1 shuts down, normal packet access will resume. Marex discovered this problem with the Mir Amateur Radio station. We then custom designed a filter by DCI, to resolve the issues. No such filter exists on ISS. http://www.marexmg.org/documents/DCIFilterProject1.doc WF1F, www.marexmg.org --- On Wed, 7/14/10, Bob Christy wrote: > From: Bob Christy > Subject: [amsat-bb] ISS - Mission Control Comm Check > To: amsat-bb@amsat.org > Date: Wednesday, July 14, 2010, 4:47 AM > Today's ISS crew schedule shows VHF > comm checks from the Russian segment while over North > America. Ground stations are at White Sands and Wallops. > > The pass is from 20:00 UTC (west coast) to 20:15 UTC (east > coast). > > VHF-1 is 143.625 MHz FM, there may also be something on > VHF-2 at 130.167 MHz. > > Bob Christy > ___ > Sent via amsat...@amsat.org. > Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur > satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Recording from HO-68 on June 20?
Would anyone happen to have any recordings from HO-68 over Fathers Day Weekend from June? I have had an unfortunate incident with my mp3 recorder which had a couple of passes of satellites from June 19 & 20 stored on it. I typically copy my recordings to a computer late in the evenings or early morning, but we were going to a family fathers day dinner and didn't get a chance to copy them over. To make my story short, I had a CreativeLabs recorder which I discovered did not like bouncing off of a brick patio. I thought it was just the switch on the unit which failed so I grabbed another unit from ebay. After putting the drive from into the new-to-me unit I was not able to recover the data. I then tried another drive with different firmware with again no success. Also the way Creative handles the formatting my PC (Windows and Linux) could not view data off of the drive. I have since grabbed a different recorder that has a good clip on it. So now I've hit the web searching for possible help. I am fairly sure the pass was Sunday the 20th, I know it was HO-68 and I worked a CM station which was maritime mobile. I have listened to the recording from K8YSE (who has a excellent site by the way) but my qso was not captured. I wish I could verify the time but in my desire to try to fix the recorder I failed to document the passes. I want to say it was around 14:00-18:00 UTC on Sunday. If anyone has a recording I would greatly appreciate if you would let me know... Thanks, Mike, K4MOA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Since there's been a lot of ISS chatter recently, I thought this might be a good time to post
Hey everyone. I'm a researcher at Cornell, and this fall, our experimental, 1 inch diameter, “chip satellites” are scheduled to be launched on the final space shuttle flight, STS-134. They're going to be mounted on the exterior of the ISS structure, and will be set to transmit a 902 MHz signal. Unfortunately, we do not yet have an antenna for receiving this transmission. After talking with Bob - Wb4APR for a while, it was suggested that the fine members of the AMSAT – BB might be able to help us. What we’re looking for is a digital capture of this 902MHz frequency (with a bandwidth of about 200KHz), during at least one ISS pass (only a few gigs of data, we believe). No decommutation or other analysis of the signal will be required, but actually capturing the signal will require at least a 20 dbB gain receive antenna (more details in a minute). If any of you can help us in this experiment, or are able to successfully capture the signal, not only would we be incredibly grateful, but we would also be prepared to add your names and contributions to all of the published papers that will result from this mission. It goes without saying, though, that we’d also be entirely open to suggestions if the community, or a member, were aware of some manner by which Cornell might be able to better avail itself to the both those who help us on this project and the community as a whole. So here are the technical details. There are 3 transmitting antennas, all tiny, center-fed dipoles: two of them use wires separated by 180 degrees, and one has wires separated by 90 degrees. Each of these dipoles is mounted a few mm from large metal panels on the ISS. The ChipSats will transmit for approximately 10ms every 1-2 seconds, but the signal is going to be beneath the noise floor. Detecting the signal requires a pseudorandom noise (PRN) code, which Cornell will handle once the dataset is in hand. Since we can/will take care of the post processing, and capture isn’t guaranteed on every ISS pass (attitude alignment problems still TBD) so anyone who can take a recording of this frequency at this bandwidth for us, of any ISS pass, would be incredibly helpful. The good news is that the chips will be live and transmitting almost immediately after they are installed from STS-134, and they will transmit continuously whenever the ISS is in sunlight. Additionally, should they survive in their environment, they are set to transmit for up to two years, which should give us many chances to receive the data and confirm that the ChipSats are functioning. Thanks for your time, everyone, Robert Christ http://www.spacecraftresearch.com/ P.S. a little extra information: Our website is http://www.spacecraftresearch.com/projects.html if you're interested. This mission isn't explicitly mentioned there yet, but is rather a proof of feasibility study for most of the projects listed on that site. Ah and lastly, the ERP of the transmitter is expected to be ~10 dBm, though it will almost certainly be facing in a poor orientation, giving us only a fraction of that power. We won't know the exact amount for a few more days. Thanks all! ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Recording from HO-68 on June 20?
Mike, Check out this page- http://www.papays.com/sat/general.html , it belongs to John K8YSE, he records all the FM passes. Dave - KB1PVH Sent from my Verizon Wireless DROID On Jul 14, 2010 12:38 PM, "Michael Elliott" wrote: Would anyone happen to have any recordings from HO-68 over Fathers Day Weekend from June? I have had an unfortunate incident with my mp3 recorder which had a couple of passes of satellites from June 19 & 20 stored on it. I typically copy my recordings to a computer late in the evenings or early morning, but we were going to a family fathers day dinner and didn't get a chance to copy them over. To make my story short, I had a CreativeLabs recorder which I discovered did not like bouncing off of a brick patio. I thought it was just the switch on the unit which failed so I grabbed another unit from ebay. After putting the drive from into the new-to-me unit I was not able to recover the data. I then tried another drive with different firmware with again no success. Also the way Creative handles the formatting my PC (Windows and Linux) could not view data off of the drive. I have since grabbed a different recorder that has a good clip on it. So now I've hit the web searching for possible help. I am fairly sure the pass was Sunday the 20th, I know it was HO-68 and I worked a CM station which was maritime mobile. I have listened to the recording from K8YSE (who has a excellent site by the way) but my qso was not captured. I wish I could verify the time but in my desire to try to fix the recorder I failed to document the passes. I want to say it was around 14:00-18:00 UTC on Sunday. If anyone has a recording I would greatly appreciate if you would let me know... Thanks, Mike, K4MOA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Chipsat
I may be missing something, but if I understand the following statement correctly: "The ChipSats will transmit for approximately 10ms every 1-2 seconds, but the signal is going to be beneath the noise floor. Detecting the signal requires a pseudorandom noise (PRN) code, which Cornell will handle once the dataset is in hand." This would require the receiving station to digitize the entire pass band, plus and minus doppler, so that Cornell could apply the PRN to pull the signal out of the noise floor for demodulation. This is beyond the capability of the "typical" ham station but may be practical with some SDR based radios. Not making use of the PRN code for the capture will mean that it will be totally blind. i.e. there will be no way to know if you are really receiving anything and if the 20 dB antenna was pointed correctly. This is certainly a challenging task. Howie AB2S _ The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5 ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Chipsat
We would of course be willing to work with anyone, and offer any help possible to individuals attempting this task, but this task is certainly not without its challenges. The positive side is that while individual passes may be blind, there are multiple passes, and anyone interested could try as many times as desired. As for digitizing the entire pass band, yes, this is what we are hoping for (though at 200KHz, this shouldn't be more than a few gigs of data). Of course, we would be willing to do any additional work in post-processing necessary, should a ground station be incapable, or partially successful, with their personal limitations. If it would help to modify the data for doppler effects, post-capture, we could investigate this as well. There is still planning time before the launch. "This is certainly a challenging task" Up to the challenge? Robert Christ On Wed, Jul 14, 2010 at 3:39 PM, Howie DeFelice wrote: > > I may be missing something, but if I understand the following statement > correctly: > > "The ChipSats will transmit for approximately 10ms every 1-2 seconds, but the > signal is going to be beneath the noise floor. Detecting the signal requires > a pseudorandom noise (PRN) code, which Cornell will handle once the dataset > is in hand." > This would require the receiving station to digitize the entire pass band, > plus and minus doppler, so that Cornell could apply the PRN to pull the signal > out of the noise floor for demodulation. This is beyond the capability of the > "typical" > ham station but may be practical with some SDR based radios. Not making use > of the PRN > code for the capture will mean that it will be totally blind. i.e. there will > be no way > to know if you are really receiving anything and if the 20 dB antenna was > pointed correctly. > This is certainly a challenging task. > > Howie > AB2S > > _ > The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with > Hotmail. > http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5 > ___ > Sent via amsat...@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Since there's been a lot of ISS chatter recently, I thought this might be a good time to post
Here is what I calculate: 10 dBm Tx power 0 dBiczero gain Tx antenna 20 dBic Rx antenna gain 0 dB Cross polarity loss 902 MHz 0.001 millions of km (1000km) 20 K sky temp 40 K Rx antenna temp 36 K receiver noise temp 20 Hz bandwidth 151.5 dB space loss at 1000km -121.5 dBm received signal level 96 K total receive system noise temp -125.8 dBm EIRP 4.3 dB S/N this was calculated using the spreadsheet I made for determining the signal from MRO: http://www.kl7uw.com/raseti.htm click on the word "calculate" to download the spreadsheet. this works for determining any spacecraft signal reception. A 20-db antenna will have around a 10 degree beamwidth so much easier to point than what hams used for AO-40 on 2.4 GHz probably a 4 to 6 foot dish will suffice. At 08:40 AM 7/14/2010, Robert Christ wrote: >Hey everyone. I'm a researcher at Cornell, and >this fall, our experimental, 1 inch diameter, >âchip satellitesâ are scheduled to be >launched on the final space shuttle flight, >STS-134. They're going to be mounted on the >exterior of the ISS structure, and will be set >to transmit a 902 MHz signal. Unfortunately, >we do not yet have an antenna for receiving this >transmission.  After talking with Bob - Wb4APR >for a while, it was suggested that the fine >members of the AMSAT BB might be able to helpp >us. What weâre looking for is a digital >capture of this 902MHz frequency (with a >bandwidth of about 200KHz), during at least one >ISS pass (only a few gigs of data, we believe). > No decommutation or other analysis of the >signal will be required, but actually capturing >the signal will require at least a 20 dbB gain >receive antenna (more details in a minute). If >any of you can help us in this experiment, or >are able to successfully capture the signal, not >only would we be incredibly grateful, but we >would also be prepared to add your names and >contributions to all of the published papers >that will result from this mission.  It goes >without saying, though, that weâd also be >entirely open to suggestions if the community, >or a member, were aware of some manner by which >Cornell might be able to better avail itself to >the both those who help us on this project and >the community as a whole. So here are the >technical details. There are 3 transmitting >antennas, all tiny, center-fed dipoles: two of >them use wires separated by 180 degrees, and one >has wires separated by 90 degrees.  Each of >these dipoles is mounted a few mm from large >metal panels on the ISS.  The ChipSats will >transmit for approximately 10ms every 1-2 >seconds, but the signal is going to be beneath >the noise floor. Detecting the signal requires >a pseudorandom noise (PRN) code, which Cornell >will handle once the dataset is in hand.  Since >we can/will take care of the post processing, >and capture isnât guaranteed on every ISS pass >(attitude alignment problems still TBD) so >anyone who can take a recording of this >frequency at this bandwidth for us, of any ISS >pass, would be incredibly helpful. The good news >is that the chips will be live and transmitting >almost immediately after they are installed from >STS-134, and they will transmit continuously >whenever the ISS is in sunlight.  Additionally, >should they survive in their environment, they >are set to transmit for up to two years, which >should give us many chances to receive the data >and confirm that the ChipSats are functioning. >Thanks for your time, everyone, Robert Christ >http://www.spacecraftresearch.com/ P.S. a little >extra information: Our website is >http://www.spacecraftresearch.com/projects.html >if you're interested. This mission isn't >explicitly mentioned there yet, but is rather a >proof of feasibility study for most of the >projects listed on that site. Ah and lastly, >the ERP of the transmitter is expected to be ~10 >dBm, though it will almost certainly be facing >in a poor orientation, giving us only a fraction >of that power. We won't know the exact amount >for a few more days. Thanks all! >___ >Sent via amsat...@amsat.org. Opinions expressed >are those of the author. Not an AMSAT-NA member? >Join now to support the amateur satellite >program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb 73, Ed - KL7UW, WD2XSH/45 == BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-QRT*, 432-100w, 1296-QRT*, 3400-fall 2010 DUBUS Magazine USA Rep dubus...@hotmail.com == *temp ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Since there's been a lot of ISS chatter recently, I thought this might be a good time to post
Sorry a labled two lines backward: -121.5 dBm is Ps signal level received from the s/c -125.8 dBm is Pn sensitivity of receive system S/N = Ps-Pn in dB I also ignored any squint angle for the transmitter on the ISS so that could add a lot more dB of loss. But the link is not as bad as one would think reading the specs. At 12:32 PM 7/14/2010, you wrote: >Here is what I calculate: >10 dBm Tx power >0 dBiczero gain Tx antenna >20 dBic Rx antenna gain >0 dB Cross polarity loss >902 MHz >0.001 millions of km (1000km) >20 K sky temp >40 K Rx antenna temp >36 K receiver noise temp >20 Hz bandwidth > >151.5 dB space loss at 1000km >-121.5 dBm received signal level >96 K total receive system noise temp >-125.8 dBm EIRP >4.3 dB S/N > >this was calculated using the spreadsheet I made >for determining the signal from MRO: >http://www.kl7uw.com/raseti.htm >click on the word "calculate" to download the spreadsheet. >this works for determining any spacecraft signal reception. > >A 20-db antenna will have around a 10 degree >beamwidth so much easier to point than what hams used for AO-40 on 2.4 GHz > >probably a 4 to 6 foot dish will suffice. > > > >At 08:40 AM 7/14/2010, Robert Christ wrote: > >Hey everyone. I'm a researcher at Cornell, and > >this fall, our experimental, 1 inch diameter, > >âchip satellitesâ are scheduled to be > >launched on the final space shuttle flight, > >STS-134. They're going to be mounted on the > >exterior of the ISS structure, and will be set > >to transmit a 902 MHz signal. Unfortunately, > >we do not yet have an antenna for receiving this > >transmission.  After talking with Bob - Wb4APR > >for a while, it was suggested that the fine > >members of the AMSAT BB might be able to helpp > >us. What weâre looking for is a digital > >capture of this 902MHz frequency (with a > >bandwidth of about 200KHz), during at least one > >ISS pass (only a few gigs of data, we believe). > > No decommutation or other analysis of the > >signal will be required, but actually capturing > >the signal will require at least a 20 dbB gain > >receive antenna (more details in a minute). If > >any of you can help us in this experiment, or > >are able to successfully capture the signal, not > >only would we be incredibly grateful, but we > >would also be prepared to add your names and > >contributions to all of the published papers > >that will result from this mission.  It goes > >without saying, though, that weâd also be > >entirely open to suggestions if the community, > >or a member, were aware of some manner by which > >Cornell might be able to better avail itself to > >the both those who help us on this project and > >the community as a whole. So here are the > >technical details. There are 3 transmitting > >antennas, all tiny, center-fed dipoles: two of > >them use wires separated by 180 degrees, and one > >has wires separated by 90 degrees.  Each of > >these dipoles is mounted a few mm from large > >metal panels on the ISS.  The ChipSats will > >transmit for approximately 10ms every 1-2 > >seconds, but the signal is going to be beneath > >the noise floor. Detecting the signal requires > >a pseudorandom noise (PRN) code, which Cornell > >will handle once the dataset is in hand.  Since > >we can/will take care of the post processing, > >and capture isnât guaranteed on every ISS pass > >(attitude alignment problems still TBD) so > >anyone who can take a recording of this > >frequency at this bandwidth for us, of any ISS > >pass, would be incredibly helpful. The good news > >is that the chips will be live and transmitting > >almost immediately after they are installed from > >STS-134, and they will transmit continuously > >whenever the ISS is in sunlight.  Additionally, > >should they survive in their environment, they > >are set to transmit for up to two years, which > >should give us many chances to receive the data > >and confirm that the ChipSats are functioning. > >Thanks for your time, everyone, Robert Christ > >http://www.spacecraftresearch.com/ P.S. a little > >extra information: Our website is > >http://www.spacecraftresearch.com/projects.html > >if you're interested. This mission isn't > >explicitly mentioned there yet, but is rather a > >proof of feasibility study for most of the > >projects listed on that site. Ah and lastly, > >the ERP of the transmitter is expected to be ~10 > >dBm, though it will almost certainly be facing > >in a poor orientation, giving us only a fraction > >of that power. We won't know the exact amount > >for a few more days. Thanks all! > >___ > >Sent via amsat...@amsat.org. Opinions expressed > >are those of the author. Not an AMSAT-NA member? > >Join now to support the amateur satellite > >program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > >73, Ed - KL7UW, WD2XSH/45 >== >BP
[amsat-bb] Re: Since there's been a lot of ISS chatter recently, I thought this might be a good time to post
My original back of the napkin calculations showed a 6-8' dish, so yes, this seems approximately correct. Point to keep in mind: the 10 dBm will not be the Tx power. 10 dBm will be the maximum Tx power. Due to bad orientation, we expect to only receive a fraction of that, unless someone gets particularly lucky with ISS orientation. I'll be simulating exactly how much of a fraction over the next few days, and of course could do so for anyone's particular location. Robert On Wed, Jul 14, 2010 at 4:32 PM, Edward R Cole wrote: > Here is what I calculate: > 10 dBm Tx power > 0 dBic zero gain Tx antenna > 20 dBic Rx antenna gain > 0 dB Cross polarity loss > 902 MHz > 0.001 millions of km (1000km) > 20 K sky temp > 40 K Rx antenna temp > 36 K receiver noise temp > 20 Hz bandwidth > > 151.5 dB space loss at 1000km > -121.5 dBm received signal level > 96 K total receive system noise temp > -125.8 dBm EIRP > 4.3 dB S/N > > this was calculated using the spreadsheet I made for determining the signal > from MRO: > http://www.kl7uw.com/raseti.htm > click on the word "calculate" to download the spreadsheet. > this works for determining any spacecraft signal reception. > > A 20-db antenna will have around a 10 degree beamwidth so much easier to > point than what hams used for AO-40 on 2.4 GHz > > probably a 4 to 6 foot dish will suffice. > > > > At 08:40 AM 7/14/2010, Robert Christ wrote: >> >> Hey everyone. I'm a researcher at Cornell, and this fall, our >> experimental, 1 inch diameter, “chip satellites†are scheduled to be >> launched on the final space shuttle flight, STS-134. They're going to be >> mounted on the exterior of the ISS structure, and will be set to transmit >> a 902 MHz signal. Unfortunately, we do not yet have an antenna for >> receiving this transmission.  After talking with Bob - Wb4APR for a while, >> it was suggested that the fine members of the AMSAT BB might be able to >> helpp us. What we’re looking for is a digital capture of this 902MHz >> frequency (with a bandwidth of about 200KHz), during at least one ISS pass >> (only a few gigs of data, we believe).  No decommutation or other analysis >> of the signal will be required, but actually capturing the signal will >> require at least a 20 dbB gain receive antenna (more details in a minute). >> If any of you can help us in this experiment, or are able to successfully >> capture the signal, not only would we be incredibly grateful, but we would >> also be prepared to add your names and contributions to all of the published >> papers that will result from this mission.  It goes without saying, though, >> that we’d also be entirely open to suggestions if the community, or a >> member, were aware of some manner by which Cornell might be able to better >> avail itself to the both those who help us on this project and the community >> as a whole. So here are the technical details. There are 3 transmitting >> antennas, all tiny, center-fed dipoles: two of them use wires separated by >> 180 degrees, and one has wires separated by 90 degrees.  Each of these >> dipoles is mounted a few mm from large metal panels on the ISS.  The >> ChipSats will transmit for approximately 10ms every 1-2 seconds, but the >> signal is going to be beneath the noise floor. Detecting the signal >> requires a pseudorandom noise (PRN) code, which Cornell will handle once the >> dataset is in hand.  Since we can/will take care of the post processing, >> and capture isn’t guaranteed on every ISS pass (attitude alignment >> problems still TBD) so anyone who can take a recording of this frequency at >> this bandwidth for us, of any ISS pass, would be incredibly helpful. The >> good news is that the chips will be live and transmitting almost immediately >> after they are installed from STS-134, and they will transmit continuously >> whenever the ISS is in sunlight.  Additionally, should they survive in >> their environment, they are set to transmit for up to two years, which >> should give us many chances to receive the data and confirm that the >> ChipSats are functioning. Thanks for your time, everyone, Robert Christ >> http://www.spacecraftresearch.com/ P.S. a little extra information: Our >> website is http://www.spacecraftresearch.com/projects.html if you're >> interested. This mission isn't explicitly mentioned there yet, but is rather >> a proof of feasibility study for most of the projects listed on that site. >> Ah and lastly, the ERP of the transmitter is expected to be ~10 dBm, though >> it will almost certainly be facing in a poor orientation, giving us only a >> fraction of that power. We won't know the exact amount for a few more days. >> Thanks all! ___ Sent via >> amsat...@amsat.org. Opinions expressed are those of the author. Not an >> AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription setti
[amsat-bb] Live Webstream of AMSAT-UK Space Colloquium
The 2010 Space Colloquium - the 25th held by AMSAT-UK, is taking place on July 31 and August 1 at the Holiday Inn in Guildford, England. As usual there will be many interesting presentations and demonstrations from the developers and users of the ever increasing number of amateur radio satellites. In addition there will be talks on nano propulsion systems, solar sails, cubesat sized linear transponders, the GENSO ground station network, GNU radios and numerous other topics. It is still possible to attend the meeting itself, although the "early booking" rates may now no longer be available - for booking details see http://www.uk.amsat.org/colloquium If, however, you are unable to attend in person, we can announce that the batc.tv webstream service will again be provided over the weekend starting from 1000BST (0900UTC) on the Saturday. The current programme - which is always subject to late changes - can be seen here http://www.uk.amsat.org/content/view/713/284/ again please note that all timings are given BST which is UTC +1. The BATC.TV webstream will be available here, click on Live Events http://www.batc.tv/ AMSAT-UK http://www.uk.amsat.org/ 73 Trevor M5AKA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: ISS
Anyone have a recording of the pass over NA at 6PM EDT, today? I worked Col. Wheelock from the mobile (5:50EDT) outside of Boston. He acknowledged calls and the fact that I was mobile. (thank you, Pete) I usually have a digital audio recorder in the car, but neglected to bring it today. Contact me at [my ca...@hotmail Bill W1PA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AO-51 obseved solar eclipse?
Greetings, I ran a simulation using the Celestia space simulator and could indeed observe a partial solar eclipse as seen from AO-51 :) I have recorded the simulation to a video and you can watch it on Youtube: http://www.youtube.com/watch?v=7ET8BhbqmVk I couldn't find any 3d model of AO-51 so I used a model of AO-7 - sorry for that. Also note that I used TLEs from today to generate orbital data for Celestia so the time and may not be scientifically accurate. If you want to run the simulation for yourself, watch from other angles, etc., you can get Celestia for free from http://shatters.net/celestia/ You'll need to add the data files for AO-51 in the "extras" folder; you can use mine to begin with. There is a .zip file here: http://files.oz9aec.net/video/SolarEclipse/ You'll also find the H.264 encoded video there that you are free to download (~100MB). 73 Alex Oz9AEC On Tue, 13 Jul 2010 13:10:41 -0400 "Mark L. Hammond" wrote: > Hello Masahiro, > > Thank you for your message! You have made a great observation, and I > think you are exactly right about the cause of the observed "glitches" > in the telemetry. Usually at this point in its orbit we would observe > AO-51 charging its batteries at a steady rate from fully illuminated > panels. > > >From what I've read from page 43 here: > http://eclipse.gsfc.nasa.gov/SEpubs/2010/TP214171a.pdf the eclipse > was from 18:15 to 20:52 UTC.Look also at the areas experiencing > eclipse. > > Please be aware that the "clock" on AO-51 runs fast. It is now about > 3 minutes fast, so look at telemetry timestamped from about 18:18 > until 20:55 UTC. > > Since the duration of the solar eclipse was 2 hrs 39 min (or 159 mins) > and AO-51 orbits every 100 minutes or so, it could have been affected > two times. > > I've plotted some of the telemetry collected from that period > (telemetry from 1800-2130utc) and posted it here: > http://www.amsat.org/amsat/ftp/telemetry/ao51/2010WOD/July2010/Wd071100_1800to2130utc_solar_eclipse.xls > > And here's a screenshot of AO-51 at the time: > http://www.amsat.org/amsat/ftp/telemetry/ao51/2010WOD/July2010/ao51_11July2010_2045utc_solar_eclipse.jpg > > 73! > > Mark N8MH > > > > 2010/7/13 Masahiro Arai : > > > > Total solar eclipse was observed in southern Pacific Ocean at 11th > > July. I checked AO-51 WOD file. Total Array I shows glitch at > > 2043-2045z. AO-51 was located on east of Argentina at the time. Is > > this glitch made with solar eclipse?? > > > > > > AO-51 Wd071100 > > 2010/7/11 > > UTC Total Array I [mA] > > 20:35 -2.111 > > 20:36 -0.323 > > 20:37 -0.323 > > 20:38 1.465 > > 20:39 -0.323 > > 20:40 528.851 > > 20:41 321.472 > > 20:42 307.170 > > 20:43 183.815 > > 20:44 190.966 > > 20:45 176.664 > > 20:46 249.962 > > 20:47 300.019 > > 20:48 396.557 > > 20:49 498.459 > > 20:50 519.912 > > 20:51 729.079 > > 20:52 634.328 > > 20:53 936.458 > > 20:54 843.495 > > 20:55 948.972 > > > > > > WOD file > > ftp://ftp.amsat.org/pub/amsat/telemetry/ao51/2010WOD/July2010/Wd071100 > > > > AO-51 WOD decoder > > http://tinyurl.com/DK3WNsoftware > > > > > > 73 > > > > Masa JN1GKZ Tokyo Japan > > > > > > > > ___ > > Sent via amsat...@amsat.org. Opinions expressed are those of the > > author. Not an AMSAT-NA member? Join now to support the amateur > > satellite program! Subscription settings: > > http://amsat.org/mailman/listinfo/amsat-bb > > > > > ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AO-51 obseved solar eclipse?
Very interesting, Alex! Thank you for sharing that video. 73, Mark N8MH At 08:37 PM 7/14/2010 +0200, Alexandru Csete wrote: >Greetings, > >I ran a simulation using the Celestia space simulator and could indeed >observe a partial solar eclipse as seen from AO-51 :) >I have recorded the simulation to a video and you can watch it on >Youtube: >http://www.youtube.com/watch?v=7ET8BhbqmVk > >I couldn't find any 3d model of AO-51 so I used a model of AO-7 - sorry >for that. Also note that I used TLEs from today to generate orbital >data for Celestia so the time and may not be scientifically accurate. > >If you want to run the simulation for yourself, watch from other >angles, etc., you can get Celestia for free from >http://shatters.net/celestia/ >You'll need to add the data files for AO-51 in the "extras" folder; >you can use mine to begin with. There is a .zip file here: >http://files.oz9aec.net/video/SolarEclipse/ > >You'll also find the H.264 encoded video there that you are free to >download (~100MB). > >73 >Alex Oz9AEC > > >On Tue, 13 Jul 2010 13:10:41 -0400 >"Mark L. Hammond" wrote: > >> Hello Masahiro, >> >> Thank you for your message! You have made a great observation, and I >> think you are exactly right about the cause of the observed "glitches" >> in the telemetry. Usually at this point in its orbit we would observe >> AO-51 charging its batteries at a steady rate from fully illuminated >> panels. >> >> >From what I've read from page 43 here: >> http://eclipse.gsfc.nasa.gov/SEpubs/2010/TP214171a.pdf the eclipse >> was from 18:15 to 20:52 UTC.Look also at the areas experiencing >> eclipse. >> >> Please be aware that the "clock" on AO-51 runs fast. It is now about >> 3 minutes fast, so look at telemetry timestamped from about 18:18 >> until 20:55 UTC. >> >> Since the duration of the solar eclipse was 2 hrs 39 min (or 159 mins) >> and AO-51 orbits every 100 minutes or so, it could have been affected >> two times. >> >> I've plotted some of the telemetry collected from that period >> (telemetry from 1800-2130utc) and posted it here: >> http://www.amsat.org/amsat/ftp/telemetry/ao51/2010WOD/July2010/Wd071100_1800to2130utc_solar_eclipse.xls >> >> And here's a screenshot of AO-51 at the time: >> http://www.amsat.org/amsat/ftp/telemetry/ao51/2010WOD/July2010/ao51_11July2010_2045utc_solar_eclipse.jpg >> >> 73! >> >> Mark N8MH >> >> >> >> 2010/7/13 Masahiro Arai : >> > >> > Total solar eclipse was observed in southern Pacific Ocean at 11th >> > July. I checked AO-51 WOD file. Total Array I shows glitch at >> > 2043-2045z. AO-51 was located on east of Argentina at the time. Is >> > this glitch made with solar eclipse?? >> > >> > >> > AO-51 Wd071100 >> > 2010/7/11 >> > UTC   Total Array I [mA] >> > 20:35  -2.111 >> > 20:36  -0.323 >> > 20:37  -0.323 >> > 20:38   1.465 >> > 20:39  -0.323 >> > 20:40  528.851 >> > 20:41  321.472 >> > 20:42  307.170 >> > 20:43  183.815 >> > 20:44  190.966 >> > 20:45  176.664 >> > 20:46  249.962 >> > 20:47  300.019 >> > 20:48  396.557 >> > 20:49  498.459 >> > 20:50  519.912 >> > 20:51  729.079 >> > 20:52  634.328 >> > 20:53  936.458 >> > 20:54  843.495 >> > 20:55  948.972 >> > >> > >> > WOD file >> > ftp://ftp.amsat.org/pub/amsat/telemetry/ao51/2010WOD/July2010/Wd071100 >> > >> > AO-51 WOD decoder >> > http://tinyurl.com/DK3WNsoftware >> > >> > >> > 73 >> > >> > Masa  JN1GKZ   Tokyo Japan >> > >> > >> > >> > ___ >> > Sent via amsat...@amsat.org. Opinions expressed are those of the >> > author. Not an AMSAT-NA member? Join now to support the amateur >> > satellite program! Subscription settings: >> > http://amsat.org/mailman/listinfo/amsat-bb >> > >> >> >> Mark L. Hammond [N8MH] ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
