[amsat-bb] Satellite Orbit Prediction in Python
I just thought I'd drop a quick note here about some fun I've been having today with satellite orbit prediction in Python. When I started mucking around with satellites, I used predict, which was pretty good, but at some point I wanted to answer some questions which weren't easy to answer using predict. Questions like when will AO-51 be visible from both my home in CM87 and locations in Hawaii, or what was the radius of the circle of visibility for AO-7 compared to ISS? Luckily, I'm a programmer. In fact, I'm a programmer who programs for fun. So, I did a bit of research, and then coded up a version of G3RUH's Plan 13 algorithm in Python, and then wrote some scripts to download elements from celestrak, and then a simple one to print data on the next pass of any named satellite. And, they worked pretty good. I've used them for the last year or so to do all my pass predictions. But there are still a couple of minor issues with the library. It didn't handle geosynchronous satellites very well. It implemented only the most basic of orbital models. I was never confident that the is this satellite in eclipse stuff working exactly right. Luckily though, it turns out that someone else has been busy writing a more complete library: PyEphem http://rhodesmill.org/pyephem/ It's a library whose primary purpose is to calculate the positions of astronomical objects.I've used it a couple of times to (for instance) figure out the size of Mars compared to Jupiter, and found it very easy to use. But today, I realized that it had a full implementation of the SGP4 and SDP4 orbital models built in, and could be used to predict satellite passes.As a proof of concept, I hacked together a 23 line script that could print the details of upcoming ISS passes. It seems to work great, and is really quite easy to use. You can find some of the simple example code at my blog: http://brainwagon.org/2009/09/27/how-to-use-python-to-predict-satellite-locations/ I'll probably be porting all of my existing scripts to use this soon. In the mean time, if you have a similar task, you might look to it to solve your custom satellite prediction problems. 73 Mark K6HX ___ 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] Sumbandila blog
For those who would like to keep up with what is happening see the following: http://sumbandilamission.blogspot.com/ Regards ZS1PK/M0PAK -- This message is subject to the CSIR's copyright terms and conditions, e-mail legal notice, and implemented Open Document Format (ODF) standard. The full disclaimer details can be found at http://www.csir.co.za/disclaimer.html. This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. MailScanner thanks Transtec Computers for their support. ___ 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: Satellite Orbit Prediction in Python
Great stuff, Mark. I'm an old, dusty assembler, and later a C programmer. Used to program for fun, then for profit, then after a few years of life I looked around and the art had snuck ahead of me. I used to hack up the PREDICT code for my own devious purposes, and just to have fun with the source. Your blog post reminded me of how fun it is to cobble together one's own code to solve a particular problem. Keep it up! Rich, N8UX Mark wrote: You can find some of the simple example code at my blog: http://brainwagon.org/2009/09/27/how-to-use-python-to-predict-satellite-locations/ I'll probably be porting all of my existing scripts to use this soon. In the mean time, if you have a similar task, you might look to it to solve your custom satellite prediction problems. 73 Mark K6HX ___ ___ 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: All Satellites
Hello AMSATs, I agree that APRS can have a higher power transmittter, because of its small amount of time to get the data broadcasted. However the workability with the HT and whipe antenna is only an advantage for the downlink. For the uplink there will be no advantage. Personally I believe that making a satellite easier accessable will also decrease its functional efficiency. This is especially the case for satellites with limited user access, like single channel FM satellites. This also includes APRS. The same issue is valide for a geostationary satellite, with the addition that a geostationary satellite would be overloaded in short time by more and more stronger stations as fixed antennas can be used. Only the uplink power level would be the parameter of competition. Resulting in a privat chat satellite for only few (high power) users. Satellites for emergency communication sounds very interresting, and personally I believe it can give a great advantage when doing it well. The question is only what will work well in an emergency situation. It will depend on the needs and the availability of equipment in the effected area. I believe that digital communication will be of limited use as you need also a computer, modem, keyboard, screen, software etc besides your radio. Only one thing missing and you will not be heared. I don't say it is impossible, but to make the system work the ground stations need to be made more easier somehow. Maybe HT APRS in combination with voice to text conversion (and opposite) would be an idea ? Besides the technical difficulty there is also the (human) organising factor. I heared some ideas about an easy to access geostationary satellite with high power downlink. That would be great, but without any communication control it would be like the FM LEOs where everyone talks at the same time and nobody is able to get there message through. It might be solved with a central control centre on a safe place (maybe by the Amateur Radio Emergency Service ?) that has control over the satellite radio and uses it as a remote radio ear in space. In this way it is also possible to use one frequency simplex system. Just some ideas, 73 de PE1RAH, William Leijenaar --- ___ 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: All Satellites
I am playing with RF modules that take ms to send not seconds 19k2 LPRS -- Andrew Rich Airways Technical Officer Grade 4 Surveillance - RADAR ADS-B Amateur Radio Callsign VK4TEC email: vk4...@tech-software.net web: www.tech-software.net - Original Message - From: William Leijenaar pe1...@yahoo.com To: amsat-bb@amsat.org Sent: Monday, September 28, 2009 8:04 PM Subject: [amsat-bb] Re: All Satellites Hello AMSATs, I agree that APRS can have a higher power transmittter, because of its small amount of time to get the data broadcasted. However the workability with the HT and whipe antenna is only an advantage for the downlink. For the uplink there will be no advantage. Personally I believe that making a satellite easier accessable will also decrease its functional efficiency. This is especially the case for satellites with limited user access, like single channel FM satellites. This also includes APRS. The same issue is valide for a geostationary satellite, with the addition that a geostationary satellite would be overloaded in short time by more and more stronger stations as fixed antennas can be used. Only the uplink power level would be the parameter of competition. Resulting in a privat chat satellite for only few (high power) users. Satellites for emergency communication sounds very interresting, and personally I believe it can give a great advantage when doing it well. The question is only what will work well in an emergency situation. It will depend on the needs and the availability of equipment in the effected area. I believe that digital communication will be of limited use as you need also a computer, modem, keyboard, screen, software etc besides your radio. Only one thing missing and you will not be heared. I don't say it is impossible, but to make the system work the ground stations need to be made more easier somehow. Maybe HT APRS in combination with voice to text conversion (and opposite) would be an idea ? Besides the technical difficulty there is also the (human) organising factor. I heared some ideas about an easy to access geostationary satellite with high power downlink. That would be great, but without any communication control it would be like the FM LEOs where everyone talks at the same time and nobody is able to get there message through. It might be solved with a central control centre on a safe place (maybe by the Amateur Radio Emergency Service ?) that has control over the satellite radio and uses it as a remote radio ear in space. In this way it is also possible to use one frequency simplex system. Just some ideas, 73 de PE1RAH, William Leijenaar --- ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.113/2399 - Release Date: 09/27/09 17:52:00 ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: FO-29 Operation
This is probably the most important email about FO-29. I've high lighted and underlined the most important parts of the message. I looks like FO-29 will not be in full operation until the first part of 2010. At this moment it is only commanded on over Japan as noted in the schedule. With the issue of the batteries, it seems JAMSAT would consider similiar operations as it is now doing when FO-29 enters long periods of darkness in the future. This would possibly allow a longer life for this great bird. Thanks to JE9PEL for this important infornation. Mike (K9QHO) AMSAT 33589 --- On Wed, 9/9/09, WILLIAMS MICHAEL k9qho6...@sbcglobal.net wrote: From: WILLIAMS MICHAEL k9qho6...@sbcglobal.net Subject: FO-29 Date: Wednesday, September 9, 2009, 11:06 PM Start of FO-29 article:- FO-29 status in 2009 FO-29 launched in August 1996 and has been working 14 years. FO-29 is planning to operate the consecutive use with the analog transponder until the end of August 2009, but it was confirmed that a transponder stopped on August 25. In the later pass, the transponder operation is confirmed when we sent a command of transponder ON from the control station, but we stopped transponder temporarily now. We had the a similar symptom of stopping the transponder in the spring of 2007 . FO-29 is in the high shade rate period now. Both of the transponder stop in the spring of 2007 and this time are thought that by this high shade rate and by the rise of the internal resistance of the deterioration of the battery and by the influence of the temperature of the battery. The power control system FO-29 (PCU) watches a terminal voltage of the battery and turns off the power supply of the transmitter automatically if it becomes less than the setting voltage. In addition, When FO-29 enters the sunshine area and it recovers to the setting voltage by sun battery power, it is designed to turn on a transmitter automatically. However malfunction occurred for this function in 2007. Because of transmitter was not turned on automatically, We made an operation schedule plan from the summer of 2007 and managed 1-2 times on in a day. This management operation worked well. The electricity income and expenditure restored or it was cured spontaneously.The transponder has been worked without control command from control station from summer of 2008. The power supply circumstances of current FO-29 is almost same situation as stop period spring of 2007, scheduled operation period, the consecutively operative period from the summer of 2008 and it is in a high shade rate. This transponder off is supposed to be a similar situation as when transponder stopped in the spring of 2007. ***From this , We decided that we make the operation schedule plan, and manage the limit of the operative number of times in one day like last time to keep the electricity income and expenditure untill improve the shade rate which is in January, 2010. --- Thanks control team JA1COU Yutaka Murata Message: 7 Date: Tue, 08 Sep 2009 20:25:03 +0900 From: Mineo Wakita ei7m-...@asahi-net.or.jp Subject: [amsat-bb] FO-29 schedule Sep. and Oct. To: amsat-bb@amsat.org Message-ID: 10ca3077029eecei7m-...@asahi-net.or.jp Content-Type: text/plain; charset=us-ascii FO-29 still has some trouble. Therefore it is examination use for a while only over Japan. We do not yet understand when it recover. There are the reception report from South America and Europe. You may listen to CW with luck over your area. Control station says that you may be listen in Australia, South America, North America, and Europe in particular. Control station says more as follows. The transmitter becomes OFF by UVC automatically in the eclipse. The station confirmed the moment when the transmitter became OFF please inform it of the date and time at the following address. lab (at) jarl.or.jp The below * is a predicted pass that command work take time. And please consent to be a possibility that we cannot turn ON the transponder by the state of the line. - September, UTC 11 21:37 12 12:21*, 22:26 13 11:30 14 22:23 15 None 16 12:15*, 22:20 17 None 18 12:03*, 22:15 19 11:15, 21:20 20 12:05* 21 12:55*, 22:58 22 10:10, 22:10 23 12:50 24 None 25 10:58, 22:50 26 11:50*, 21:55 27 12:36* 28 21:50 29 12:35*, 22:45 30 11:40*, 21:45 October, UTC 1 12:30*, 22:35 2 11:35, 21:45 3 12:25, 22:28 4 11:28 5 22:25 6 13:08, 21:33 7 12:10, 22:23 8 13:05, 21:35 9 None 10 11:12, 23:08 11 12:05*, 22:12 12 11:08 13 None - JE9PEL, Mineo Wakita -- ___ 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] Symposium Restaurant Locations
All, I had to go on some unexpected travel out of BWI the past couple of weeks. So I did some reconnaissance and developed a couple of maps that depict restaurants near the hotel and airport. You can retrieve these at the AMSAT Symposium Web Site. Go to the food and drink icon and click on the pdf or ppt file. I also included in this package directions to the GM Restaurant which is close to the hotel. This restaurant just received the WTOP Best Crab Cake award through a survey from the radio station's Baltimore/Washington listeners. This restaurant has good food at reasonable prices. We will be including paper copies of these maps in the symposium registration packet. But wanted to give you a heads up, so you can plan out your meals. And if you haven't registered for the symposium yet, please do so. We are less than 2 weeks away!! 73, Frank, KA3HDO ___ 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: All Satellites
Bruce Robertson wrote: On Mon, Sep 28, 2009 at 7:04 AM, William Leijenaar pe1...@yahoo.com wrote: Hello AMSATs, I agree that APRS can have a higher power transmittter, because of its small amount of time to get the data broadcasted. However the workability with the HT and whipe antenna is only an advantage for the downlink. For the uplink there will be no advantage. Personally I believe that making a satellite easier accessable will also decrease its functional efficiency. This is especially the case for satellites with limited user access, like single channel FM satellites. This also includes APRS. The same issue is valide for a geostationary satellite, with the addition that a geostationary satellite would be overloaded in short time by more and more stronger stations as fixed antennas can be used. Only the uplink power level would be the parameter of competition. Resulting in a privat chat satellite for only few (high power) users. Satellites for emergency communication sounds very interresting, and personally I believe it can give a great advantage when doing it well. The question is only what will work well in an emergency situation. It will depend on the needs and the availability of equipment in the effected area. I believe that digital communication will be of limited use as you need also a computer, modem, keyboard, screen, software etc besides your radio. Only one thing missing and you will not be heared. I don't say it is impossible, but to make the system work the ground stations need to be made more easier somehow. Maybe HT APRS in combination with voice to text conversion (and opposite) would be an idea ? In some cases, the groundstation situation might not be as complicated as you describe. The popular TH-D7A Kenwood HT, though no longer manufactured, has integrated APRS messaging with a TNC on board. So, too, does Yaesu's new VX-8R. And there are mobile 2m radios with similar capabilities. Moreover, if there were a wide satellite network of APRS birds, we could hope that even more new HTs would include this feature, since the cost of implementing a modem is quite low these days. Not to be picky but the VX-8 do not have an inbuilt TNC but it has a TNC doing APRS and could not be used to connect to a computer. But i think that APRS is a nice function for the sats. It's easy to use and you can do i.e e-mail too. It's easy to operate and requires very little hardware to operate. APRS is a nice mode to allow more people use the same bandwidth. Doing the sats portable with voice is not always an easy task if the majority is using rotators and high power. I really would like more APRS sats and more igates as i'm happy with messaging capability and positioning. Most new tracker like TinyTrack etc have message and display capability so that you don't need a special made APRS radio. Kai Gunter LA3QMA ___ 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: FO-29 Operation
I don't see anything highlighted or underlined! WILLIAMS MICHAEL wrote: This is probably the most important email about FO-29. I've high lighted and underlined the most important parts of the message. I looks like FO-29 will not be in full operation until the first part of 2010. At this moment it is only commanded on over Japan as noted in the schedule. With the issue of the batteries, it seems JAMSAT would consider similiar operations as it is now doing when FO-29 enters long periods of darkness in the future. This would possibly allow a longer life for this great bird. Thanks to JE9PEL for this important infornation. Mike (K9QHO) AMSAT 33589 --- On Wed, 9/9/09, WILLIAMS MICHAEL k9qho6...@sbcglobal.net wrote: From: WILLIAMS MICHAEL k9qho6...@sbcglobal.net Subject: FO-29 Date: Wednesday, September 9, 2009, 11:06 PM Start of FO-29 article:- FO-29 status in 2009 FO-29 launched in August 1996 and has been working 14 years. FO-29 is planning to operate the consecutive use with the analog transponder until the end of August 2009, but it was confirmed that a transponder stopped on August 25. In the later pass, the transponder operation is confirmed when we sent a command of transponder ON from the control station, but we stopped transponder temporarily now. We had the a similar symptom of stopping the transponder in the spring of 2007 . FO-29 is in the high shade rate period now. Both of the transponder stop in the spring of 2007 and this time are thought that by this high shade rate and by the rise of the internal resistance of the deterioration of the battery and by the influence of the temperature of the battery. The power control system FO-29 (PCU) watches a terminal voltage of the battery and turns off the power supply of the transmitter automatically if it becomes less than the setting voltage. In addition, When FO-29 enters the sunshine area and it recovers to the setting voltage by sun battery power, it is designed to turn on a transmitter automatically. However malfunction occurred for this function in 2007. Because of transmitter was not turned on automatically, We made an operation schedule plan from the summer of 2007 and managed 1-2 times on in a day. This management operation worked well. The electricity income and expenditure restored or it was cured spontaneously.The transponder has been worked without control command from control station from summer of 2008. The power supply circumstances of current FO-29 is almost same situation as stop period spring of 2007, scheduled operation period, the consecutively operative period from the summer of 2008 and it is in a high shade rate. This transponder off is supposed to be a similar situation as when transponder stopped in the spring of 2007. ***From this , We decided that we make the operation schedule plan, and manage the limit of the operative number of times in one day like last time to keep the electricity income and expenditure untill improve the shade rate which is in January, 2010. --- Thanks control team JA1COU Yutaka Murata Message: 7 Date: Tue, 08 Sep 2009 20:25:03 +0900 From: Mineo Wakita ei7m-...@asahi-net.or.jp Subject: [amsat-bb] FO-29 schedule Sep. and Oct. To: amsat-bb@amsat.org Message-ID: 10ca3077029eecei7m-...@asahi-net.or.jp Content-Type: text/plain; charset=us-ascii FO-29 still has some trouble. Therefore it is examination use for a while only over Japan. We do not yet understand when it recover. There are the reception report from South America and Europe. You may listen to CW with luck over your area. Control station says that you may be listen in Australia, South America, North America, and Europe in particular. Control station says more as follows. The transmitter becomes OFF by UVC automatically in the eclipse. The station confirmed the moment when the transmitter became OFF please inform it of the date and time at the following address. lab (at) jarl.or.jp The below * is a predicted pass that command work take time. And please consent to be a possibility that we cannot turn ON the transponder by the state of the line. - September, UTC 11 21:37 12 12:21*, 22:26 13 11:30 14 22:23 15 None 16 12:15*, 22:20 17 None 18 12:03*, 22:15 19 11:15, 21:20 20 12:05* 21 12:55*, 22:58 22 10:10, 22:10 23 12:50 24 None 25 10:58, 22:50 26 11:50*, 21:55 27 12:36* 28 21:50 29 12:35*, 22:45 30 11:40*, 21:45 October, UTC 1 12:30*, 22:35 2 11:35, 21:45 3 12:25, 22:28 4 11:28 5 22:25 6 13:08, 21:33 7 12:10, 22:23 8 13:05, 21:35 9 None 10 11:12, 23:08 11 12:05*, 22:12 12 11:08 13 None - JE9PEL, Mineo Wakita --
[amsat-bb] Re: Satellite Orbit Prediction in Python
Awesome stuff!! I'll have to check out this library tonight. I started hacking at something similar but started digging into the internals of SGP4/SDP4, then got distracted and never finished. If you have a rotator, it'd be a cool quick project to slap pyserial on there and control your rotator. It'd be pretty awesome to have a Kep to Rotator Control in about 10 lines of code :-) Joe On Mon, Sep 28, 2009 at 4:12 AM, Rich Dailey (Gmail) redail...@gmail.comwrote: Great stuff, Mark. I'm an old, dusty assembler, and later a C programmer. Used to program for fun, then for profit, then after a few years of life I looked around and the art had snuck ahead of me. I used to hack up the PREDICT code for my own devious purposes, and just to have fun with the source. Your blog post reminded me of how fun it is to cobble together one's own code to solve a particular problem. Keep it up! Rich, N8UX Mark wrote: You can find some of the simple example code at my blog: http://brainwagon.org/2009/09/27/how-to-use-python-to-predict-satellite-locations/ I'll probably be porting all of my existing scripts to use this soon. In the mean time, if you have a similar task, you might look to it to solve your custom satellite prediction problems. 73 Mark K6HX ___ ___ 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: keps
ANDE POLLUX SPHERE 1 35693U 09038E 09270.75161923 .00024150 0-0 11738-3 0 589 2 35693 051.6396 136.9854 0002884 219.5067 140.5754 15.82296457 9347 ANDE CASTOR SPHERE 1 35694U 09038F 09271.09002049 .00012500 0-0 65843-4 0 562 2 35694 051.6405 135.5071 0003090 230.6994 129.3762 15.81148215 9394 TATIANA-2 (RS-28) 1 35868U 09049D 09269.80165911 +.0177 +0-0 +1-3 0 00113 2 35868 098.7998 319.9570 0005066 042.4864 317.6631 14.22084863001298 SUMBANDILA 1 35870U 09049F 09271.12594053 .2270 0-0 1-3 0 236 2 35870 097.3722 320.9996 0010180 259.0098 185.4894 15.22803326 1581 SWISSCUBE 1 35932U 09051B 09269.75151502 +.5219 +0-0 +12986-2 0 00074 2 35932 098.3367 004.4323 0007042 275.0402 084.9893 14.52119461000510 UWE-2 1 35933U 09051C 09269.75016994 +.7797 +0-0 +19109-2 0 00088 2 35933 098.3342 004.4307 0004574 288.0186 072.0499 14.52693268000518 BEESAT 1 35934U 09051D 09270.71435912 .3303 0-0 81574-3 076 2 35934 098.3277 005.3821 0005951 295.3450 064.7052 14.52721073 656 ITUpSAT1 1 35935U 09051E 09271.19850776 .1930 0-0 48744-3 075 2 35935 098.3396 005.8711 0007236 274.7355 085.3039 14.52122969 715 ___ 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] HamSat iPhone App
An update has just been released and it is very good. The improvements are extensive and useful. 73, Bob KIØG ___ 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: Sumbandila blog
On 28 Sep 2009 at 9:52, Pieter Kotze wrote: Date sent: Mon, 28 Sep 2009 09:52:52 +0200 From: Pieter Kotze pko...@csir.co.za Subject:[amsat-bb] Sumbandila blog To: amsat-bb@amsat.org For those who would like to keep up with what is happening see the following: http://sumbandilamission.blogspot.com/ Regards ZS1PK/M0PAK From this site what we can read does not seems to be very positive for a long trouble free operation? Could be some hardware are not radiation resistant or enough to sustain long nominal operation. One factor will remain radiation will not vanished and the effect on material will only added up. There seems to be a high incidence of Single Event Effects (SEE) due to radiation, especially on the On-Board Computer (OBC). We have however designed all the electronics with latch-up protection, so none of the SEE occurrences to date have caused any permanent damage. Sometimes an SEE causes the OBC to reset and we have recently noticed that an auto restart of the processor then does not fully complete. With the WOD now available to us it seems that the lengthening of a timing constraint in software will be able to alleviate this problem. Note that we could not test for SEE on the ground so were not able to observe this timing effect prior to launch. I just hope they will be able to go around theses issues - Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE ___ 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: Symposium Restaurant Locations
In a message dated 9/28/2009 7:47:44 AM Central Daylight Time, ka3...@comcast.net writes: Subj: [amsat-bb] Symposium Restaurant Locations Date:9/28/2009 7:47:44 AM Central Daylight Time From:ka3...@comcast.net To:amsat-bb@amsat.org Received from Internet: All, I had to go on some unexpected travel out of BWI the past couple of weeks. So I did some reconnaissance and developed a couple of maps that depict restaurants near the hotel and airport. You can retrieve these at the AMSAT Symposium Web Site. Go to the food and drink icon and click on the pdf or ppt file. I also included in this package directions to the GM Restaurant which is close to the hotel. This restaurant just received the WTOP Best Crab Cake award through a survey from the radio station's Baltimore/Washington listeners. This restaurant has good food at reasonable prices. We will be including paper copies of these maps in the symposium registration packet. But wanted to give you a heads up, so you can plan out your meals. And if you haven't registered for the symposium yet, please do so. We are less than 2 weeks away!! 73, Frank, KA3HDO ___ 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 Thank's for reminding me about GM's. This is the place that we frequently sent out to for Subs at all hours when working late at Westinghouse - BWI in the 70s and 80s. We nicknamed it Grease and Mayonaise but it was excellent. The last time I ate there it had expanded into a very good full service restaurant, but still retined the Sub Shop as well. I hope the Sunset Restaurant in Glen Burnie made the list. http://www.sunsetrestaurant.com/ 73 - Keith, W5IU ___ 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: All Satellites (Alan P. Biddle)
FDMDV uses a 1400 bps codec, occupies only 1100 Hz and operates with any SSB transceiver. Comunications doesn't have to be full duplex. At 12-16 kbps the satellite and ground stations could alternate with short bursts of voice or text. This wouldn't fit in a 2.4 kHz SSB bandwidth but would require a 16-20 kHz wide filter or use of a transverter and a simple SDR radio like the SoftRock. 73, John KD6OZH - Original Message - From: Gordon JC Pearce gordon...@gjcp.net KD6OZH's mentioning of a 1200 bps voice codec is very interesting, too. I see that DSTAR's AMBE is down to 2000 with error correction, and Speex operates down to 2000, too, though I think without error correction. (I find the latter much more engaging as a ham, since it is open source.) It would be a hoot to do a voice conference over the Internet using a sample of low bitrate codecs and just get a sense of what might be possible. One downside of voice is that it would occupy the transponder far more than messaging, and Bob's favorable power calculations would need to be estimated downwards. Would the packet satellite be capable of bent-pipe operation though? You'd need to transmit and receive simultaneously to get that working. I'd far prefer to use Speex rather than the locked-down proprietary AMBE codecs. ___ 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: SAT32PC issue-sat drops off
Craig, I have not had this problem but have heard you mention it before. I did have a pass come up way off frequency and not sure why that happened...has only happened once as far as I remember. Hope you catch you on VO-52 soon. David K6CDW -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of D. Craig Fox Sent: Sunday, September 27, 2009 8:40 PM To: amsat-bb@amsat.org Subject: [amsat-bb] SAT32PC issue-sat drops off hello all on this distinguished listserv! I love staying in the loop thru this listerv. But I digress. Recently I notice that VO52 has been getting dropped off of my sat 32 pc sat list. I have to make a point of adding it back on. This never used to happen. Any clues/suggestions? Thanks in advance! Craig N6RSX AMSAT # 36607 - NOTICE: This communication may contain privileged or other confidential information. If you are not the intended recipient of this communication, or an employee or agent responsible for delivering this communication to the intended recipient, please advise the sender by reply email and immediately delete the message and any attachments without copying or disclosing the contents. Thank you. ___ 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] kpc9612
hi all, the kpc9612 will not do 300 baud on one port and 1200 on the other. what were they thinking when they made this. geee. all along thought it did. kc8gkf ___ 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] FO-29
When posting to AMSAT-BB, the high lighting and underlining must have been stripped. Here is what I high lighted and underlined. 1. FO-29 is in the high shade rate period now. 2. high shade rate and by the rise of the internal resistance of the deterioration of the battery and by the influence of the temperature of the battery. 3.it is designed to turn on a transmitter automatically. However malfunction occurred for this function in 2007. 4. The transponder has been worked without control command from control station from summer of 2008. 5. ***From this , We decided that we make the operation schedule plan, and manage the limit of the operative number of times in one day like last time to keep the electricity income and expenditure untill improve the shade rate which is in January, 2010. 6. The transmitter becomes OFF by UVC automatically in the eclipse. All the best, Mike (K9QHO) ___ 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: Satellite Orbit Prediction in Python
Joseph Armbruster wrote: Awesome stuff!! I'll have to check out this library tonight. I started hacking at something similar but started digging into the internals of SGP4/SDP4, then got distracted and never finished. If you have a rotator, it'd be a cool quick project to slap pyserial on there and control your rotator. It'd be pretty awesome to have a Kep to Rotator Control in about 10 lines of code :-) Joe That reminds me, I should give thanks to Howard, G6LVB. I've never met Howard, but his G6LVB tracker project first put me onto G3RUH's Plan 13 work. Howards PIC based tracker implements Plan 13 to do automatic antenna guiding, and seems very cool. I have actually experimented with using my library to predict and compensate for Doppler shift using my FT-817.I used pyserial to send out frequency change commands as documented in the FT-817 manual. It worked reasonably well. For example, following is a simple visual display of a pass of the three small satellites COMPASS-1, CUTE-1.7 APD and SEEDS that I did back on Jun 13, 2008. WARNING: this JPG is 1.7Mb, and 1600x8000 or so in size. Don't blame me if your computer melts trying to display it. http://brainwagon.org/wp-content/uploads/2008/06/three.jpg You can see COMPASS-1 at the beginning, with its sharply whistling tones. Then CUTE will step in, and finally SEEDS. You can clearly see the steps in frequency every second or so. If you'd rather have the audio, you can get it here: http://brainwagon.org/wp-content/uploads/2008/06/threefer-20080613.mp3 73 Mark K6HX ___ 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: Cute 1.7 Re-Entry
I posted the following on this a week or so ago: Spacetrack is predicting that CUTE 1.7 will decay on 10th October. My predix software predicts that the first time the satellite hits terra firma will be 19th December. What do others think? John Heath wrote: Hi Based on day 271 keps from Celestrak the Perigee height for Cute 1.7 Object 28941 has now dropped below 300km. Re-entry probably early October. Anyone care to predict the date and time? If you would, how about sending it to me off list. g7...@btinternet.com I will complile a table and provide a small prize for the person who is nearest. Closing date midnight utc last day of September. 73 John G7HIA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.113/2400 - Release Date: 09/28/09 05:51:00 -- Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032 Amateur Radio G8IFF W8IFF (was KC8NHF), e-mail ni...@ngunn.net www http://www.ngunn.net Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pigs QRP Club International #385, Dayton ARA #2128, AMSAT-NA LM-1691, AMSAT-UK 0182, MKARS, ALC, GCARES, XWARN. ___ 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: Cute 1.7 Re-Entry
Hi Nigel, Thanks for alerting me, and the list, to the upcommong re-entry. I have been tracking the orbital changes of the Castor Pollux pair with an interest. Their mass differences are showing up quite clearly in the Mean Motion. Cute 1.7 is different again being such a small mass, and adds another level of interest. Glad to have your prediction to add to the table. 73 John G7HIA From: Nigel Gunn G8IFF/W8IFF ni...@ngunn.net To: John Heath g7...@btinternet.com Cc: Amsat amsat-bb@AMSAT.Org Sent: Monday, 28 September, 2009 6:36:55 PM Subject: [amsat-bb] Re: Cute 1.7 Re-Entry I posted the following on this a week or so ago: Spacetrack is predicting that CUTE 1.7 will decay on 10th October. My predix software predicts that the first time the satellite hits terra firma will be 19th December. What do others think? John Heath wrote: Hi Based on day 271 keps from Celestrak the Perigee height for Cute 1.7 Object 28941 has now dropped below 300km. Re-entry probably early October. Anyone care to predict the date and time? If you would, how about sending it to me off list. g7...@btinternet.com I will complile a table and provide a small prize for the person who is nearest. Closing date midnight utc last day of September. 73 John G7HIA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.113/2400 - Release Date: 09/28/09 05:51:00 -- Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032 Amateur Radio G8IFF W8IFF (was KC8NHF), e-mail ni...@ngunn.net www http://www.ngunn.net Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pigs QRP Club International #385, Dayton ARA #2128, AMSAT-NA LM-1691, AMSAT-UK 0182, MKARS, ALC, GCARES, XWARN. ___ 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: Satellite Orbit Prediction in Python
Bryan, Thanks for the link especially to the source as I am very interested in implementing something very similar. (for my QTH of course) Thanks Josh Smith KD8HRX email/jabber: juice...@gmail.com phone: 304.237.9369(c) On Mon, Sep 28, 2009 at 2:41 PM, Bryan Klofas bklo...@gmail.com wrote: Hey Mark-- We also use pyephem for web-based pass times calculations at Cal Poly. http://mstl.atl.calpoly.edu/~ops/passtimes/ Source is here, but it was written a few years back, and uses the older (now depreciated) ephem.Body attributes. It also sometimes has trouble with the formatting on the webpage, although that may be a firefox bug, I'm not sure. http://mstl.atl.calpoly.edu/~ops/passtimes/passtimes.py -- Bryan Klofas, KF6ZEO Mark VandeWettering wrote: I just thought I'd drop a quick note here about some fun I've been having today with satellite orbit prediction in Python. When I started mucking around with satellites, I used predict, which was pretty good, but at some point I wanted to answer some questions which weren't easy to answer using predict. Questions like when will AO-51 be visible from both my home in CM87 and locations in Hawaii, or what was the radius of the circle of visibility for AO-7 compared to ISS? Luckily, I'm a programmer. In fact, I'm a programmer who programs for fun. So, I did a bit of research, and then coded up a version of G3RUH's Plan 13 algorithm in Python, and then wrote some scripts to download elements from celestrak, and then a simple one to print data on the next pass of any named satellite. And, they worked pretty good. I've used them for the last year or so to do all my pass predictions. But there are still a couple of minor issues with the library. It didn't handle geosynchronous satellites very well. It implemented only the most basic of orbital models. I was never confident that the is this satellite in eclipse stuff working exactly right. Luckily though, it turns out that someone else has been busy writing a more complete library: PyEphem http://rhodesmill.org/pyephem/ It's a library whose primary purpose is to calculate the positions of astronomical objects. I've used it a couple of times to (for instance) figure out the size of Mars compared to Jupiter, and found it very easy to use. But today, I realized that it had a full implementation of the SGP4 and SDP4 orbital models built in, and could be used to predict satellite passes. As a proof of concept, I hacked together a 23 line script that could print the details of upcoming ISS passes. It seems to work great, and is really quite easy to use. You can find some of the simple example code at my blog: http://brainwagon.org/2009/09/27/how-to-use-python-to-predict-satellite-locations/ I'll probably be porting all of my existing scripts to use this soon. In the mean time, if you have a similar task, you might look to it to solve your custom satellite prediction problems. 73 Mark K6HX ___ 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] FT-897D Fine Tuning
Does the use of a CAT cable and Ham Radio Deluxe allow me to tune the vfo with Better resolution than the current 10Hz? That's what I currently get with the Dial set to FINE . Ordered the cable and programming software, but was curious. I like doing the FMT's and would like to have more resolution .. Randy - N2CUA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Sill question
Randy wrote: Has anyone tried any digital modes thru the satellites? Uhmmm not APRS .. I mean like RTTY or PSK31 ?? I guess you would have to try that on a linear bird .. But I am guessing that the doppler would be a major problem? Like I said .. Silly question.. Randy - N2CUA Hellschreiber works really well, I've used it several times. There has been a fair amount of SSTV over the years as well. 73, Drew KO4MA ___ 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: Fox Delta ST2
I bought one a couple of months ago, but haven't had time to build it yet. Looks very nice, all quality parts, and the shipping was quite fast, considering it came from India. Jim KQ6EA --- On Mon, 9/28/09, Randy rswa...@twcny.rr.com wrote: From: Randy rswa...@twcny.rr.com Subject: [amsat-bb] Fox Delta ST2 To: amsat-bb@amsat.org Date: Monday, September 28, 2009, 4:58 PM I am thinking about getting this interface to control my rotor. Was wondering if others have it and if so , how do you like it? Other rotor controller preferences? Randy - N2CUA ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Road trip to DM07 this weekend.
Hey all, I will be working every possible pass of ao27, so5o, and ao-51 starting noonish friday oct 2 pacific time. We will end mid day on sunday. This and DM08 may be valuable to some. I will sql each call that needs one. Have a great weekend Steve. KI6OQU Sent via BlackBerry by ATT ___ 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
