From sierra_mtnview at sbcglobal.net Thu Dec 17 17:00:46 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Thu, 17 Dec 2009 14:00:46 -0800 Subject: [AstroPy] Meteor Methods--Atmospheric Trajectories, PC Book on Astronmy In-Reply-To: <40e64fa20912091858k4262fa21k362476e7801669b4@mail.gmail.com> References: <4B0C4E70.5060608@sbcglobal.net> <40e64fa20911241602p707fecbbw9cfa743401ba1ce3@mail.gmail.com> <4B0D52D0.6040200@sbcglobal.net> <4B140E41.6000302@sbcglobal.net> <40e64fa20912091858k4262fa21k362476e7801669b4@mail.gmail.com> Message-ID: <4B2AAA0E.2000509@sbcglobal.net> Hi, the problem is very complex. I only cited the book as a reference to give some idea of how what the plate reduction phase is done for an ordinary camera. I think the first solution to the more general method was provided by Ceplecha in his 1989 paper. He goes into multiple station observations, ground track, atmospheric track, orbit calculation and more.Our observations are from two video cameras spaced about 35 miles away. I was hoping to turn up someone who might be familiar with these ideas. I've begun working with a pro astronomer who has a fairly decent handle on these matters, and, I'm at the early stages of trying some methods he proposed. If nothing else, I think some rough estimates of the two trajectories can be made without months of coding. What I find odd about this type of meteor work is that I have yet to see it mentioned in any book on celestial mechanics. There are a number of papers on the web, but it takes a bit to understand them. Further, no one seems to have recently written any code to do the calculations. Ceplecha wrote a 4000 line FORTRAN program for it all, but it is no longer available. Paul Barrett wrote: > Hi Wayne, > > Sorry to take so long to respond. I have not been able to look at the > book that you referred to on Amazon - I will check it out of the > library tomorrow, but am quite familiar with the algorithms. What > exactly are are you trying to do? Do you have CCD images that you > would like to get accurate star positions from, or are you trying to > use known star positions to accurately measure the position of an > asteroid or similar object? These are variations on the same problem, > but the algorithms differ, i.e., can be simplified, depending on the > question that you are trying to ask. The latter problem just requires > accurately estimating the plate parameters in order to measure the > object's position. The size of the matrix depends on the number of > stars that have been measured and the number of plate or image > parameters. Of course there is freely available software that can do > much of this for you. Let me know your exact problem and I'll try to > provide a more explicit response. > > -- Paul > > On Mon, Nov 30, 2009 at 1:26 PM, Wayne Watson > wrote: > >> I sent a follow up msg that would make this easier; however, the >> moderator is holding on to it. It had attachments. >> >> Wayne Watson wrote: >> >>> Perhaps the best way is to refer you to the 2009 edition of the book. >>> You'll be using the Amazon Search Book facility. They've made it a bit >>> harder to use, perhaps, but the paragraph below will let you piece >>> together the critical pages in the astrometry section. I have some these >>> pages copied from a much earlier book, and this section has definitely >>> been expanded. The ppmcat portion I finally direct you looks like a big >>> improvement on the tiny catalog they used in an earlier edition. >>> >>> >>> See the Look Inside icon on the upper left and enter the word astrometry >>> when the small dialog window opens up. You will then see the first page >>> that shows that word. Use the right button to go to the next result. >>> That is the page that's the start of chapter 12. Now use the right arrow >>> to move through the pages. I can only get through the first three pages, >>> but you'll begin to see what they are doing. To go further, do this. Go >>> back to the search dialog and enter "plate reduction" (no quotes). Skip >>> to the second result and you should be on page 254. Now use the arrow to >>> go to successive pages. You'll get some more info about what they are >>> doing. If you care to go on, go back to find again and enter squares >>> adjustment. Move via next button to 256, then move ahead one page at a >>> time. By then you should have a good idea of what this is about. >>> >>> To get a summary of that section use ppmcat for find. Some of the >>> summary pages are blocked, but at least you'll get some idea what all >>> this produces. >>> >>> Paul Barrett wrote: >>> >>> >>>> Wayne, >>>> >>>> I am not familiar with the book, but your comment about astrometry >>>> caught my eye. We are currently implementing the plate reduction >>>> methods as part of our work, actually on a much larger scale, of order >>>> one million images. These calculations should be easy to do in Python >>>> for just a few images. The important point is to properly set up the >>>> arrays. You can then use the routines in scipy to do the least squares >>>> adjustment. >>>> >>>> I might be able to help if you can describe you problem in more detail. >>>> >>>> -- Paul >>>> >>>> On Tue, Nov 24, 2009 at 4:21 PM, Wayne Watson >>>> wrote: >>>> >>>> >>>> >>>>> Is anyone familiar with some of the mathematical methods for calculating >>>>> atmospheric trajectories for two stations. Have they been implemented in >>>>> Python? >>>>> >>>>> There's a computer book with the title something like PC Computations >>>>> for Astronomy. (Ah, Astronomy for the Personal Computer) I believe the >>>>> latest version provides methods for C++, and earlier editions for older >>>>> languages. In one of the later chapters the authors delve into what I >>>>> think is called plate reduction. (Ah, the chapter is titled Astrometry.) >>>>> The idea is that an image of the night sky is provided and a catalog is >>>>> examined to identify stars on the image. Has anyone implemented the >>>>> various algorithms used for this in Python? >>>>> >>>>> -- >>>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>>> >>>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>>>> >>>>> 350 350 350 350 350 350 350 350 350 350 >>>>> Make the number famous. See 350.org >>>>> The major event has passed, but keep the number alive. >>>>> >>>>> Web Page: >>>>> >>>>> _______________________________________________ >>>>> AstroPy mailing list >>>>> AstroPy at scipy.org >>>>> http://mail.scipy.org/mailman/listinfo/astropy >>>>> >>>>> >>>>> >>>>> >>>> >>> >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >> >> The popular press and many authorities believe the number >> of pedifiles that prowl the web is 50,00. There are no >> figures that support this. The number of children below >> 18 years of age kidnapped by strangers is 1 in 600,00, >> or 115 per year. -- The Science of Fear by D. Gardner >> >> Web Page: >> >> _______________________________________________ >> AstroPy mailing list >> AstroPy at scipy.org >> http://mail.scipy.org/mailman/listinfo/astropy >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Thu Dec 17 17:00:54 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Thu, 17 Dec 2009 14:00:54 -0800 Subject: [AstroPy] Meteor Methods--Atmospheric Trajectories, PC Book on Astronmy In-Reply-To: <40e64fa20912091858k4262fa21k362476e7801669b4@mail.gmail.com> References: <4B0C4E70.5060608@sbcglobal.net> <40e64fa20911241602p707fecbbw9cfa743401ba1ce3@mail.gmail.com> <4B0D52D0.6040200@sbcglobal.net> <4B140E41.6000302@sbcglobal.net> <40e64fa20912091858k4262fa21k362476e7801669b4@mail.gmail.com> Message-ID: <4B2AAA16.5000606@sbcglobal.net> Hi, the problem is very complex. I only cited the book as a reference to give some idea of how what the plate reduction phase is done for an ordinary camera. I think the first solution to the more general method was provided by Ceplecha in his 1989 paper. He goes into multiple station observations, ground track, atmospheric track, orbit calculation and more.Our observations are from two video cameras spaced about 35 miles away. I was hoping to turn up someone who might be familiar with these ideas. I've begun working with a pro astronomer who has a fairly decent handle on these matters, and, I'm at the early stages of trying some methods he proposed. If nothing else, I think some rough estimates of the two trajectories can be made without months of coding. What I find odd about this type of meteor work is that I have yet to see it mentioned in any book on celestial mechanics. There are a number of papers on the web, but it takes a bit to understand them. Further, no one seems to have recently written any code to do the calculations. Ceplecha wrote a 4000 line FORTRAN program for it all, but it is no longer available. Paul Barrett wrote: > Hi Wayne, > > Sorry to take so long to respond. I have not been able to look at the > book that you referred to on Amazon - I will check it out of the > library tomorrow, but am quite familiar with the algorithms. What > exactly are are you trying to do? Do you have CCD images that you > would like to get accurate star positions from, or are you trying to > use known star positions to accurately measure the position of an > asteroid or similar object? These are variations on the same problem, > but the algorithms differ, i.e., can be simplified, depending on the > question that you are trying to ask. The latter problem just requires > accurately estimating the plate parameters in order to measure the > object's position. The size of the matrix depends on the number of > stars that have been measured and the number of plate or image > parameters. Of course there is freely available software that can do > much of this for you. Let me know your exact problem and I'll try to > provide a more explicit response. > > -- Paul > > On Mon, Nov 30, 2009 at 1:26 PM, Wayne Watson > wrote: > >> I sent a follow up msg that would make this easier; however, the >> moderator is holding on to it. It had attachments. >> >> Wayne Watson wrote: >> >>> Perhaps the best way is to refer you to the 2009 edition of the book. >>> You'll be using the Amazon Search Book facility. They've made it a bit >>> harder to use, perhaps, but the paragraph below will let you piece >>> together the critical pages in the astrometry section. I have some these >>> pages copied from a much earlier book, and this section has definitely >>> been expanded. The ppmcat portion I finally direct you looks like a big >>> improvement on the tiny catalog they used in an earlier edition. >>> >>> >>> See the Look Inside icon on the upper left and enter the word astrometry >>> when the small dialog window opens up. You will then see the first page >>> that shows that word. Use the right button to go to the next result. >>> That is the page that's the start of chapter 12. Now use the right arrow >>> to move through the pages. I can only get through the first three pages, >>> but you'll begin to see what they are doing. To go further, do this. Go >>> back to the search dialog and enter "plate reduction" (no quotes). Skip >>> to the second result and you should be on page 254. Now use the arrow to >>> go to successive pages. You'll get some more info about what they are >>> doing. If you care to go on, go back to find again and enter squares >>> adjustment. Move via next button to 256, then move ahead one page at a >>> time. By then you should have a good idea of what this is about. >>> >>> To get a summary of that section use ppmcat for find. Some of the >>> summary pages are blocked, but at least you'll get some idea what all >>> this produces. >>> >>> Paul Barrett wrote: >>> >>> >>>> Wayne, >>>> >>>> I am not familiar with the book, but your comment about astrometry >>>> caught my eye. We are currently implementing the plate reduction >>>> methods as part of our work, actually on a much larger scale, of order >>>> one million images. These calculations should be easy to do in Python >>>> for just a few images. The important point is to properly set up the >>>> arrays. You can then use the routines in scipy to do the least squares >>>> adjustment. >>>> >>>> I might be able to help if you can describe you problem in more detail. >>>> >>>> -- Paul >>>> >>>> On Tue, Nov 24, 2009 at 4:21 PM, Wayne Watson >>>> wrote: >>>> >>>> >>>> >>>>> Is anyone familiar with some of the mathematical methods for calculating >>>>> atmospheric trajectories for two stations. Have they been implemented in >>>>> Python? >>>>> >>>>> There's a computer book with the title something like PC Computations >>>>> for Astronomy. (Ah, Astronomy for the Personal Computer) I believe the >>>>> latest version provides methods for C++, and earlier editions for older >>>>> languages. In one of the later chapters the authors delve into what I >>>>> think is called plate reduction. (Ah, the chapter is titled Astrometry.) >>>>> The idea is that an image of the night sky is provided and a catalog is >>>>> examined to identify stars on the image. Has anyone implemented the >>>>> various algorithms used for this in Python? >>>>> >>>>> -- >>>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>>> >>>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>>>> >>>>> 350 350 350 350 350 350 350 350 350 350 >>>>> Make the number famous. See 350.org >>>>> The major event has passed, but keep the number alive. >>>>> >>>>> Web Page: >>>>> >>>>> _______________________________________________ >>>>> AstroPy mailing list >>>>> AstroPy at scipy.org >>>>> http://mail.scipy.org/mailman/listinfo/astropy >>>>> >>>>> >>>>> >>>>> >>>> >>> >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >> >> The popular press and many authorities believe the number >> of pedifiles that prowl the web is 50,00. There are no >> figures that support this. The number of children below >> 18 years of age kidnapped by strangers is 1 in 600,00, >> or 115 per year. -- The Science of Fear by D. Gardner >> >> Web Page: >> >> _______________________________________________ >> AstroPy mailing list >> AstroPy at scipy.org >> http://mail.scipy.org/mailman/listinfo/astropy >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Thu Dec 17 20:33:52 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Thu, 17 Dec 2009 17:33:52 -0800 Subject: [AstroPy] Rotating and Transforming Vectors--Flight Path of a Celestial Body Message-ID: <4B2ADC00.307@sbcglobal.net> I'm just getting used to the math and numpy library, and have begun working on a problem of the following sort. Two observing stations are equidistant, 1/2 degree, on either side of a line of longitude of 90 deg west, and both are at 45 deg latitude. Given the earth's circumference as 25020 miles, a meteor is 60 miles above the point between the two sites. That is, if you were standing at long 90deg and lat 45 deg, the meteor would be that high above you. 70 miles along the long line is 1 degree, so the stations are 70 miles apart. I want to know the az and el of the meteor from each station. With some geometry and trig, I've managed to get that first point; however, I can see moving the meteor say, 1/2 deg, along its circular path towards the north pole is going to require more pen and pencil work to get the az/el for it. Long ago in a faraway time, I used to do this stuff. It should be easy to rotate the vector to the first point 1/2 deg northward, and find the vector there, then compute the new az and el from each station. Maybe. I'm just beginning to look at the matrix and vector facilities in numpy. Maybe someone can comment on how this should be done, and steer me towards what I need to know in numpy. -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From peridot.faceted at gmail.com Thu Dec 17 23:55:42 2009 From: peridot.faceted at gmail.com (Anne Archibald) Date: Thu, 17 Dec 2009 23:55:42 -0500 Subject: [AstroPy] Rotating and Transforming Vectors--Flight Path of a Celestial Body In-Reply-To: <4B2ADC00.307@sbcglobal.net> References: <4B2ADC00.307@sbcglobal.net> Message-ID: 2009/12/17 Wayne Watson : > I'm just getting used to the math and numpy library, and have begun > working on a problem of the following sort. > > Two observing stations are equidistant, 1/2 degree, on either side of a > line of longitude of 90 deg west, and both are at 45 deg latitude. Given > the earth's circumference as 25020 miles, a meteor is 60 miles above the > point between the two sites. That is, if you were standing at long > 90deg ?and lat 45 deg, the meteor would be that high above you. 70 miles > along the long line is 1 degree, so the stations are 70 miles apart. ?I > want to know the az and el of the meteor from each station. ?With some > geometry and trig, I've managed to get that first point; however, ?I can > see ?moving the meteor say, 1/2 deg, along its circular path towards the > north pole is going to require more pen and pencil work to get the az/el > for it. > > Long ago in a faraway time, I used to do this stuff. It should be easy > to rotate the vector to the first point 1/2 deg northward, and find the > vector there, then compute the new az and el from each station. Maybe. > I'm just beginning to look at the matrix and vector facilities in numpy. > Maybe someone can comment on how this should be done, and steer me > towards what I need to know in numpy. You may find that the problem grows drastically easier if you work as much as possible in so-called earth-centered earth-fixed coordinates (sometimes called XYZ) coordinates. These are a rectilinear coordinate system that rotates with the earth, with the Z axis through the north pole and the X axis through the equator at the Greenwich meridian. It's kind of horrible for getting altitudes, since the Earth is sort of pear-shaped, but it makes the 3D geometry much simpler. If you don't go this route, I'd recommend picking one station and defining a rectilinear coordinate system based on its north and vertical vectors. The north and vertical vectors of the other station will be at somewhat funny angles (unless you can get away with treating the Earth as flat between the two), but whatever rectilinear coordinates you choose, a dot product lets you calculate vector lengths and angles between them, and a cross product lets you build vectors orthogonal to a given pair. So, for example, if your station has north vector N and up vector U, you can get its east vector as E=cross(N,U) (then normalize it); if you want to convert an absolute north to a local north (i.e. one that is horizontal) you can do N=cross(E,U) (and normalize it). Then you can get the azimuth of a vector V using dot(N,V)/sqrt(dot(V,V)) and dot(E,V)/sqrt(dot(V,V)). Anne From sierra_mtnview at sbcglobal.net Fri Dec 18 10:15:21 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Fri, 18 Dec 2009 07:15:21 -0800 Subject: [AstroPy] Meteor Methods--Atmospheric Trajectories, PC Book on Astronomy In-Reply-To: <40e64fa20912180620m215c048axdc1541ea0b0ac2af@mail.gmail.com> References: <4B0C4E70.5060608@sbcglobal.net> <40e64fa20911241602p707fecbbw9cfa743401ba1ce3@mail.gmail.com> <4B0D52D0.6040200@sbcglobal.net> <4B140E41.6000302@sbcglobal.net> <40e64fa20912091858k4262fa21k362476e7801669b4@mail.gmail.com> <4B2AA9B0.5010703@sbcglobal.net> <40e64fa20912171813w37890ef8p1b53c50e227f4cd7@mail.gmail.com> <4B2AF754.1000502@sbcglobal.net> <40e64fa20912180620m215c048axdc1541ea0b0ac2af@mail.gmail.com> Message-ID: <4B2B9C89.7070906@sbcglobal.net> It's the latter. If I understand your question correctly, the parallax is the angle the two planes make with one another, the angle of intersection. Ceplecha, I think I mentioned him, calls it Q. As the measure shrinks, the intersection fit loses its significance. I'm attaching his paper and a related one. (Omitted on post to mail list.) Paul Barrett wrote: > Yes, I understand. My question was do you intend to get the parallax > of the meteor trail using a simultaneous set of equations for each > plate or process each plate separately and then estimate the parallax. > Your response below indicates the latter: process each plate > separately and then determine the parallax. We will have to solve a > similar problem in the future. We may want to start looking into it > now. I'll let you know if I have any updates. > > -- Paul > > On Thu, Dec 17, 2009 at 10:30 PM, Wayne Watson > wrote: > >> Hi. >> Together. That is data from two stations widely separated, maybe 40-170 >> miles, possibly more. A meteor at 60 miles can be seen by an observer over >> an elevation of 15-20 degrees some 3-400 miles away. The rough idea is to ID >> stars in the image, and do a plate reduction to bring out dim stars, and >> identify them and produce their ra/dec. One then uses the reduction to get >> ra/dec on the track for each station. A plane is passed through each station >> and it's tracks. The two planes produce an intersection, and that is the >> track. It gets pretty deep, but those are necessary steps to get anything. >> >> One image might work in some usual case like a meteor flying directly >> overhead. >> >> Paul Barrett wrote: >> >>> Hi Wayne, >>> >>> Are you trying to calculate the meteor trajectory using both images >>> simultaneously or processing each image separately and then calculate >>> the trajectory? >>> >>> On Thu, Dec 17, 2009 at 4:59 PM, Wayne Watson >>> wrote: >>> >>> >>>> Hi, the problem is very complex. I only cited the book as a reference to >>>> give some idea of how what the plate reduction phase is done for an >>>> ordinary >>>> camera. >>>> >>>> I think the first solution to the more general method was provided by >>>> Ceplecha in his 1989 paper. He goes into multiple station observations, >>>> ground track, atmospheric track, orbit calculation and more.Our >>>> observations >>>> are from two video cameras spaced about 35 miles away. >>>> >>>> I was hoping to turn up someone who might be familiar with these ideas. >>>> I've >>>> begun working with a pro astronomer who has a fairly decent handle on >>>> these >>>> matters, and, I'm at the early stages of trying some methods he proposed. >>>> If >>>> nothing else, I think some rough estimates of the two trajectories can be >>>> made without months of coding. >>>> >>>> What I find odd about this type of meteor work is that I have yet to see >>>> it >>>> mentioned in any book on celestial mechanics. There are a number of >>>> papers >>>> on the web, but it takes a bit to understand them. Further, no one seems >>>> to >>>> have recently written any code to do the calculations. Ceplecha wrote a >>>> 4000 >>>> line FORTRAN program for it all, but it is no longer available. >>>> >>>> Paul Barrett wrote: >>>> >>>> >>>>> Hi Wayne, >>>>> >>>>> Sorry to take so long to respond. I have not been able to look at the >>>>> book that you referred to on Amazon - I will check it out of the >>>>> library tomorrow, but am quite familiar with the algorithms. What >>>>> exactly are are you trying to do? Do you have CCD images that you >>>>> would like to get accurate star positions from, or are you trying to >>>>> use known star positions to accurately measure the position of an >>>>> asteroid or similar object? These are variations on the same problem, >>>>> but the algorithms differ, i.e., can be simplified, depending on the >>>>> question that you are trying to ask. The latter problem just requires >>>>> accurately estimating the plate parameters in order to measure the >>>>> object's position. The size of the matrix depends on the number of >>>>> stars that have been measured and the number of plate or image >>>>> parameters. Of course there is freely available software that can do >>>>> much of this for you. Let me know your exact problem and I'll try to >>>>> provide a more explicit response. >>>>> >>>>> -- Paul >>>>> >>>>> On Mon, Nov 30, 2009 at 1:26 PM, Wayne Watson >>>>> wrote: >>>>> >>>>> >>>>> >>>>>> I sent a follow up msg that would make this easier; however, the >>>>>> moderator is holding on to it. It had attachments. >>>>>> >>>>>> Wayne Watson wrote: >>>>>> >>>>>> >>>>>> >>>>>>> Perhaps the best way is to refer you to the 2009 edition of the book. >>>>>>> You'll be using the Amazon Search Book facility. They've made it a bit >>>>>>> harder to use, perhaps, but the paragraph below will let you piece >>>>>>> together the critical pages in the astrometry section. I have some >>>>>>> these >>>>>>> pages copied from a much earlier book, and this section has definitely >>>>>>> been expanded. The ppmcat portion I finally direct you looks like a >>>>>>> big >>>>>>> improvement on the tiny catalog they used in an earlier edition. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> See the Look Inside icon on the upper left and enter the word >>>>>>> astrometry >>>>>>> when the small dialog window opens up. You will then see the first >>>>>>> page >>>>>>> that shows that word. Use the right button to go to the next result. >>>>>>> That is the page that's the start of chapter 12. Now use the right >>>>>>> arrow >>>>>>> to move through the pages. I can only get through the first three >>>>>>> pages, >>>>>>> but you'll begin to see what they are doing. To go further, do this. >>>>>>> Go >>>>>>> back to the search dialog and enter "plate reduction" (no quotes). >>>>>>> Skip >>>>>>> to the second result and you should be on page 254. Now use the arrow >>>>>>> to >>>>>>> go to successive pages. You'll get some more info about what they are >>>>>>> doing. If you care to go on, go back to find again and enter squares >>>>>>> adjustment. Move via next button to 256, then move ahead one page at a >>>>>>> time. By then you should have a good idea of what this is about. >>>>>>> >>>>>>> To get a summary of that section use ppmcat for find. Some of the >>>>>>> summary pages are blocked, but at least you'll get some idea what all >>>>>>> this produces. >>>>>>> >>>>>>> Paul Barrett wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>>> Wayne, >>>>>>>> >>>>>>>> I am not familiar with the book, but your comment about astrometry >>>>>>>> caught my eye. We are currently implementing the plate reduction >>>>>>>> methods as part of our work, actually on a much larger scale, of >>>>>>>> order >>>>>>>> one million images. These calculations should be easy to do in >>>>>>>> Python >>>>>>>> for just a few images. The important point is to properly set up the >>>>>>>> arrays. You can then use the routines in scipy to do the least >>>>>>>> squares >>>>>>>> adjustment. >>>>>>>> >>>>>>>> I might be able to help if you can describe you problem in more >>>>>>>> detail. >>>>>>>> >>>>>>>> -- Paul >>>>>>>> >>>>>>>> On Tue, Nov 24, 2009 at 4:21 PM, Wayne Watson >>>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>> Is anyone familiar with some of the mathematical methods for >>>>>>>>> calculating >>>>>>>>> atmospheric trajectories for two stations. Have they been >>>>>>>>> implemented >>>>>>>>> in >>>>>>>>> Python? >>>>>>>>> >>>>>>>>> There's a computer book with the title something like PC >>>>>>>>> Computations >>>>>>>>> for Astronomy. (Ah, Astronomy for the Personal Computer) I believe >>>>>>>>> the >>>>>>>>> latest version provides methods for C++, and earlier editions for >>>>>>>>> older >>>>>>>>> languages. In one of the later chapters the authors delve into what >>>>>>>>> I >>>>>>>>> think is called plate reduction. (Ah, the chapter is titled >>>>>>>>> Astrometry.) >>>>>>>>> The idea is that an image of the night sky is provided and a catalog >>>>>>>>> is >>>>>>>>> examined to identify stars on the image. Has anyone implemented the >>>>>>>>> various algorithms used for this in Python? >>>>>>>>> >>>>>>>>> -- >>>>>>>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>>>>>>> >>>>>>>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>>>>>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>>>>>>>> >>>>>>>>> 350 350 350 350 350 350 350 350 350 350 >>>>>>>>> Make the number famous. See 350.org >>>>>>>>> The major event has passed, but keep the number alive. >>>>>>>>> >>>>>>>>> Web Page: >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> AstroPy mailing list >>>>>>>>> AstroPy at scipy.org >>>>>>>>> http://mail.scipy.org/mailman/listinfo/astropy >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> -- >>>>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>>>> >>>>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>>>>> >>>>>> The popular press and many authorities believe the number >>>>>> of pedifiles that prowl the web is 50,00. There are no >>>>>> figures that support this. The number of children below >>>>>> 18 years of age kidnapped by strangers is 1 in 600,00, >>>>>> or 115 per year. -- The Science of Fear by D. Gardner >>>>>> >>>>>> Web Page: >>>>>> >>>>>> _______________________________________________ >>>>>> AstroPy mailing list >>>>>> AstroPy at scipy.org >>>>>> http://mail.scipy.org/mailman/listinfo/astropy >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>> -- >>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>> >>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>>> "... humans'innate skills with numbers isn't much >>>> better than that of rats and dolphins." >>>> -- >>>> Stanislas Dehaene, neurosurgeon >>>> Web Page: >>>> >>>> >>>> >>>> >>> >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >> "... humans'innate skills with numbers isn't much >> better than that of rats and dolphins." -- >> Stanislas Dehaene, neurosurgeon >> Web Page: >> >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Wed Dec 23 00:37:58 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Tue, 22 Dec 2009 21:37:58 -0800 Subject: [AstroPy] 3-D Graphics Tools for for Documentation, Presentations, etc. In-Reply-To: <49EB1DC5.8060109@sbcglobal.net> References: <49EB1DC5.8060109@sbcglobal.net> Message-ID: <4B31ACB6.2050003@sbcglobal.net> It was some months ago when I posted this, and had limited time to really look at the tools suggested. I did delve into Visual Python, but it wasn't really suitable for the task. I ended up doing my drawings in Word, and omitted spheres and arcs for the most part, but did draw coordinate systems with labels. It worked. However, I still am curious about drawing coordinate systems. In my present case I have three coordinate systems going for two observing stations on the earth, a meteor moving overhead, and the general earht centered system. What I'm ultimately trying to do is to solve for the az-el of points on the meteor path (great circle is fine, 60 miles high), for each station. Currently, I'm drawing this with pencil and paper. It's working, and helps my thinking and computations. It does produce a lot erasures and re-draws. I'd be curious if anyone has done this in mayavi2 or S2PLOT? Any examples? I have more freedom to see what's available. Wayne Watson wrote: > Many years ago to put together a presentation or article on celestial > mechanics, spherical trig, trajectory analysis, etc. I would use a > compass, ruler, and maybe a French curve to draw the figures, coordinate > axes, etc. on paper. Labels would be typed onto the sheets. I would like > to think that over the last decade that some modest software package > might be available to do this. Does anyone know of any? > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From William.T.Bridgman at nasa.gov Wed Dec 23 07:45:42 2009 From: William.T.Bridgman at nasa.gov (Bridgman, William T.) Date: Wed, 23 Dec 2009 07:45:42 -0500 Subject: [AstroPy] 3-D Graphics Tools for for Documentation, Presentations, etc. In-Reply-To: <4B31ACB6.2050003@sbcglobal.net> References: <49EB1DC5.8060109@sbcglobal.net> <4B31ACB6.2050003@sbcglobal.net> Message-ID: <6A282341-1FE4-42A0-81FA-4D41F2C45498@nasa.gov> If you are doing line plots, I believe matplotlib has some 3-D capabilities. http://matplotlib.sourceforge.net/ For 3-D datasets, I've had good luck with VisIt https://wci.llnl.gov/codes/visit/ If you are trying to do line drawings, Pyx has some of this capability but you'd have to do the 3-d projection yourself. http://pyx.sourceforge.net/ I've used Inkscape for Illustrator-type applicatios http://www.inkscape.org/ although some of its functionality is limited. For 3-D rendered plots, I've used pyPOV with POVray. http://code.google.com/p/pypov/ http://www.povray.org/ but these are steep learning curves. Tom On Dec 23, 2009, at 12:37 AM, Wayne Watson wrote: > It was some months ago when I posted this, and had limited time to > really look at the tools suggested. I did delve into Visual Python, > but > it wasn't really suitable for the task. I ended up doing my drawings > in > Word, and omitted spheres and arcs for the most part, but did draw > coordinate systems with labels. It worked. However, I still am curious > about drawing coordinate systems. > > In my present case I have three coordinate systems going for two > observing stations on the earth, a meteor moving overhead, and the > general earht centered system. What I'm ultimately trying to do is to > solve for the az-el of points on the meteor path (great circle is > fine, > 60 miles high), for each station. Currently, I'm drawing this with > pencil and paper. It's working, and helps my thinking and > computations. > It does produce a lot erasures and re-draws. I'd be curious if anyone > has done this in mayavi2 or S2PLOT? Any examples? I have more > freedom to > see what's available. > > > > Wayne Watson wrote: >> Many years ago to put together a presentation or article on celestial >> mechanics, spherical trig, trajectory analysis, etc. I would use a >> compass, ruler, and maybe a French curve to draw the figures, >> coordinate >> axes, etc. on paper. Labels would be typed onto the sheets. I would >> like >> to think that over the last decade that some modest software package >> might be available to do this. Does anyone know of any? >> >> > > -- > Wayne Watson (Watson Adventures, Prop., Nevada City, CA) > > (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) > Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet > > "... humans'innate skills with numbers isn't much > better than that of rats and dolphins." > -- Stanislas Dehaene, neurosurgeon > > Web Page: > > _______________________________________________ > AstroPy mailing list > AstroPy at scipy.org > http://mail.scipy.org/mailman/listinfo/astropy -- Dr. William T."Tom" Bridgman Scientific Visualization Studio Global Science & Technology, Inc. NASA/Goddard Space Flight Center Email: William.T.Bridgman at nasa.gov Code 610.3 Phone: 301-286-1346 Greenbelt, MD 20771 FAX: 301-286-1634 http://svs.gsfc.nasa.gov/ From sierra_mtnview at sbcglobal.net Sat Dec 26 11:51:10 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Sat, 26 Dec 2009 08:51:10 -0800 Subject: [AstroPy] Source Extraction from Star Trails? Message-ID: <4B363EFE.9040102@sbcglobal.net> Does anyone know of a program that produces selected star trails on a az equal-distance projection of the sky? Ultimately, it would be good if the program could match these trails against composite (long exposure) all-sky (fisheye) images. From that data, it would be useful to produce the location of the north celestial pole, north azimuth position, and possibly the zenith. Aside from possible star catalog need, one would need to supply lat/long, start time of trails, and maybe 5-10 stars that require trails for some specified time. -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Sat Dec 26 13:20:08 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Sat, 26 Dec 2009 10:20:08 -0800 Subject: [AstroPy] A Web Book--Foundations of Celestial Mechanics Message-ID: <4B3653D8.5050102@sbcglobal.net> I was roaming the web this morning looking for some reference material, and found this It looks quite good. Free. . The author seems to have gone to considerable length to make it available. -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Mon Dec 28 11:32:02 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Mon, 28 Dec 2009 08:32:02 -0800 Subject: [AstroPy] Is There an AstroCalc Modulo? Message-ID: <4B38DD82.4080709@sbcglobal.net> See Subject. I'm looking for something like the methods described in Meeus' Astro Formulae for Calculators. Something too that provides rotation matrices, calculations to find sidereal time, and az equal-distance projections. -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sierra_mtnview at sbcglobal.net Mon Dec 28 11:40:46 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Mon, 28 Dec 2009 08:40:46 -0800 Subject: [AstroPy] Is There an AstroCalc Module? Message-ID: <4B38DF8E.3040901@sbcglobal.net> See Subject. I'm looking for something like the methods described in Meeus' Astro Formulae for Calculators. Something too that provides rotation matrices, calculations to find sidereal time, and az equal-distance projections. -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: _______________________________________________ AstroPy mailing list AstroPy at scipy.org http://mail.scipy.org/mailman/listinfo/astropy From sransom at nrao.edu Mon Dec 28 11:53:24 2009 From: sransom at nrao.edu (Scott Ransom) Date: Mon, 28 Dec 2009 11:53:24 -0500 Subject: [AstroPy] Is There an AstroCalc Modulo? In-Reply-To: <4B38DD82.4080709@sbcglobal.net> References: <4B38DD82.4080709@sbcglobal.net> Message-ID: <200912281153.24377.sransom@nrao.edu> Hi Wayne, I wrapped all of SLALIB a year or two ago and it has most or all of what you are looking for I think. You can get it here: http://www.cv.nrao.edu/~sransom/pyslalib-1.0.tar.gz Scott On Monday 28 December 2009 11:32:02 am Wayne Watson wrote: > See Subject. I'm looking for something like the methods described in > Meeus' Astro Formulae for Calculators. Something too that provides > rotation matrices, calculations to find sidereal time, and az > equal-distance projections. > -- Scott M. Ransom Address: NRAO Phone: (434) 296-0320 520 Edgemont Rd. email: sransom at nrao.edu Charlottesville, VA 22903 USA GPG Fingerprint: 06A9 9553 78BE 16DB 407B FFCA 9BFA B6FF FFD3 2989 From wmcclain at watershade.net Mon Dec 28 11:56:27 2009 From: wmcclain at watershade.net (Bill McClain) Date: Mon, 28 Dec 2009 10:56:27 -0600 Subject: [AstroPy] Is There an AstroCalc Modulo? In-Reply-To: <4B38DD82.4080709@sbcglobal.net> References: <4B38DD82.4080709@sbcglobal.net> Message-ID: <20091228105627.35beb4c9@montag.site> On Mon, 28 Dec 2009 08:32:02 -0800 Wayne Watson wrote: > See Subject. I'm looking for something like the methods described in > Meeus' Astro Formulae for Calculators. Something too that provides > rotation matrices, calculations to find sidereal time, and az > equal-distance projections. See also http://astrolabe.sourceforge.net/ which has Python and C++ version of much of his later book. -Bill -- Sattre Press History of Astronomy http://sattre-press.com/ During the 19th Century info at sattre-press.com by Agnes M. Clerke http://sattre-press.com/han.html From sierra_mtnview at sbcglobal.net Mon Dec 28 13:27:43 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Mon, 28 Dec 2009 10:27:43 -0800 Subject: [AstroPy] Is There an AstroCalc Modulo? In-Reply-To: <200912281153.24377.sransom@nrao.edu> References: <4B38DD82.4080709@sbcglobal.net> <200912281153.24377.sransom@nrao.edu> Message-ID: <4B38F89F.5080706@sbcglobal.net> Hello. What is SLALAB, and where do I put the unzipped file (Windows)? Is there documentation for this? Scott Ransom wrote: > Hi Wayne, > > I wrapped all of SLALIB a year or two ago and it has most or all of what > you are looking for I think. You can get it here: > > http://www.cv.nrao.edu/~sransom/pyslalib-1.0.tar.gz > > Scott > > On Monday 28 December 2009 11:32:02 am Wayne Watson wrote: > >> See Subject. I'm looking for something like the methods described in >> Meeus' Astro Formulae for Calculators. Something too that provides >> rotation matrices, calculations to find sidereal time, and az >> equal-distance projections. >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "... humans'innate skills with numbers isn't much better than that of rats and dolphins." -- Stanislas Dehaene, neurosurgeon Web Page: From sransom at nrao.edu Mon Dec 28 13:41:11 2009 From: sransom at nrao.edu (Scott Ransom) Date: Mon, 28 Dec 2009 13:41:11 -0500 Subject: [AstroPy] Is There an AstroCalc Modulo? In-Reply-To: <4B38F89F.5080706@sbcglobal.net> References: <4B38DD82.4080709@sbcglobal.net> <200912281153.24377.sransom@nrao.edu> <4B38F89F.5080706@sbcglobal.net> Message-ID: <200912281341.11466.sransom@nrao.edu> Hi Wayne, SLALIB is a professional-grade library of Astronomical routines, mostly for coordinate and time conversion. You can find documentation of all the routines at many sites on the web. e.g.: http://star-www.rl.ac.uk/star/docs/sun67.htx/sun67.html You install it using the normal "python setup.py install" in the directory where it was unzipped. However, I've never used it under Windows and am not sure if anything special is needed or not (I suspect there will be some trickery involved). Scott On Monday 28 December 2009 01:27:43 pm you wrote: > Hello. What is SLALAB, and where do I put the unzipped file > (Windows)? Is there documentation for this? > > Scott Ransom wrote: > > Hi Wayne, > > > > I wrapped all of SLALIB a year or two ago and it has most or all of > > what you are looking for I think. You can get it here: > > > > http://www.cv.nrao.edu/~sransom/pyslalib-1.0.tar.gz > > > > Scott > > > > On Monday 28 December 2009 11:32:02 am Wayne Watson wrote: > >> See Subject. I'm looking for something like the methods described > >> in Meeus' Astro Formulae for Calculators. Something too that > >> provides rotation matrices, calculations to find sidereal time, > >> and az equal-distance projections. > -- Scott M. Ransom Address: NRAO Phone: (434) 296-0320 520 Edgemont Rd. email: sransom at nrao.edu Charlottesville, VA 22903 USA GPG Fingerprint: 06A9 9553 78BE 16DB 407B FFCA 9BFA B6FF FFD3 2989 From sierra_mtnview at sbcglobal.net Tue Dec 29 13:43:01 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Tue, 29 Dec 2009 10:43:01 -0800 Subject: [AstroPy] Determining DST in Python? Message-ID: <4B3A4DB5.6070505@sbcglobal.net> I'm trying to adjust a years worth of date-time stamps to UTC, and would like to determine where DST starts and finishes in years from about 2006 to 2009. Is there an "easy" way to do this? -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "We're leaving you with a world that runs like clockwork. And the clock it runs like is a cuckoo clock." -- Frank Oppenheimer, physicist Web Page: From sierra_mtnview at sbcglobal.net Tue Dec 29 19:22:47 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Tue, 29 Dec 2009 16:22:47 -0800 Subject: [AstroPy] Determining DST in Python? In-Reply-To: References: <4B3A4DB5.6070505@sbcglobal.net> Message-ID: <4B3A9D57.305@sbcglobal.net> Yes, I've begun to prowl around in that murky library. It has just a bit too much to 'easily' digest at the moment. I have used several of the functions. I would think that someone has faced this issue before. For the moment, the best I can think of is hard coding dates-times for my time zone in each of the last 3 years. I think there really only four, 2 for the past year, and 2 for prior years. I really only need to worry about my particularly time zone, Calif. Anne Archibald wrote: > 2009/12/29 Wayne Watson : > >> I'm trying to adjust a years worth of date-time stamps to UTC, and would >> like to determine where DST starts and finishes in years from about 2006 >> to 2009. Is there an "easy" way to do this? >> > > You can almost certainly do this with the standard library's datetime module: > http://docs.python.org/library/datetime.html > > Anne > > >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >> >> "We're leaving you with a world that runs like >> clockwork. And the clock it runs like is a cuckoo >> clock." -- Frank Oppenheimer, physicist >> >> Web Page: >> >> _______________________________________________ >> AstroPy mailing list >> AstroPy at scipy.org >> http://mail.scipy.org/mailman/listinfo/astropy >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "We're leaving you with a world that runs like clockwork. And the clock it runs like is a cuckoo clock." -- Frank Oppenheimer, physicist Web Page: From sierra_mtnview at sbcglobal.net Tue Dec 29 21:49:37 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Tue, 29 Dec 2009 18:49:37 -0800 Subject: [AstroPy] Determining DST in Python? In-Reply-To: <4B3A9D57.305@sbcglobal.net> References: <4B3A4DB5.6070505@sbcglobal.net> <4B3A9D57.305@sbcglobal.net> Message-ID: <4B3ABFC1.1000003@sbcglobal.net> This should do it for now. 2010 March 14 November 07 March 28 October 31 Sunday, March 8, 2009 at 2:00:00 AM Sunday, November 1, 2009 at 2:00:00 AM In 2008, daylight time begins on March 9 and ends on November 2. In 2007, daylight time begins on March 11 and ends on November 4.New Law NASA has a nice site all the way out to 2015 . Wayne Watson wrote: > Yes, I've begun to prowl around in that murky library. It has just a > bit too much to 'easily' digest at the moment. I have used several of > the functions. I would think that someone has faced this issue > before. For the moment, the best I can think of is hard coding > dates-times for my time zone in each of the last 3 years. I think there > really only four, 2 for the past year, and 2 for prior years. I really > only need to worry about my particularly time zone, Calif. > > Anne Archibald wrote: > >> 2009/12/29 Wayne Watson : >> >> >>> I'm trying to adjust a years worth of date-time stamps to UTC, and would >>> like to determine where DST starts and finishes in years from about 2006 >>> to 2009. Is there an "easy" way to do this? >>> >>> >> You can almost certainly do this with the standard library's datetime module: >> http://docs.python.org/library/datetime.html >> >> Anne >> >> >> >>> -- >>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>> >>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet >>> >>> "We're leaving you with a world that runs like >>> clockwork. And the clock it runs like is a cuckoo >>> clock." -- Frank Oppenheimer, physicist >>> >>> Web Page: >>> >>> _______________________________________________ >>> AstroPy mailing list >>> AstroPy at scipy.org >>> http://mail.scipy.org/mailman/listinfo/astropy >>> >>> >>> >> >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "We're leaving you with a world that runs like clockwork. And the clock it runs like is a cuckoo clock." -- Frank Oppenheimer, physicist Web Page: From sierra_mtnview at sbcglobal.net Wed Dec 30 14:07:17 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Wed, 30 Dec 2009 11:07:17 -0800 Subject: [AstroPy] Is There an AstroCalc Module? In-Reply-To: <4FEEB42C-4B53-4EC9-8293-200D4D3BA5CA@uw.edu> References: <4B38DF8E.3040901@sbcglobal.net> <8044925C-1661-4AF6-800E-64D2E3515EED@uw.edu> <4B38FA1D.2050009@sbcglobal.net> <4FEEB42C-4B53-4EC9-8293-200D4D3BA5CA@uw.edu> Message-ID: <4B3BA4E5.50500@sbcglobal.net> Before I install it, is there a document that summarizes what's in it? That is, gives a brief summary of each function? Russell Owen wrote: > The RO package is pure python so I only have a source code version > available. That is the one you want. > > I suggest you use "easy_install" or "pip" to install it. > > You can also install it by downloading it and running "setup.py > install" in the main directory--though it may require setuptools. Once > you have installed setuptools you have "easy_install" so you might as > well use that. (pip also requires setuptools -- nearly any sort of > installer does these days). > > Or if you wish to avoid setuptools then you can download the source > and copy or move the "RO" directory (/python/RO) into > your site-packages directory. I don't know where site-packages is on > Windows. > > Regards, > > -- Russell > > On Dec 28, 2009, at 10:34 AM, Wayne Watson wrote: > >> Hi, I'm on Python 2.5, Windows. Are any of the downloads on the link >> applicable to my situation? If I use it, where under c:/Python25 do I >> put it? Lib? >> >> Russell Owen wrote: >>> There is various software that will perform astronomical >>> transformations of time and position. I do not know what exists for >>> projections (other than any projections that might exist in >>> matplotlib). >>> >>> One option is RO.Astro >>> , which I >>> wrote. The routines are easy to use (see documentation in doc >>> strings) and the coordinate transformations are performed to high >>> accuracy. It is pure python (though it uses numpy) so it is trivial >>> to install and fully cross-platform, but not as fast as some other >>> options. >>> >>> Overview: >>> RO.Sph: handles computations in spherical coordinates (e.g. RA/Dec >>> to Az/Alt). RO.Sph.coordConv is the "do it all" routine. It also has >>> angSideAng, a routine to handle spherical geometry computations, and >>> routines to convert between spherical and cartesian coordinates. >>> RO.Cnv: handles computations in cartesian coordinates; this is where >>> most of the real computations are performed >>> RO.Tm: handles various time computations >>> >>> >>> -- Russell >>> >>> On Dec 28, 2009, at 8:40 AM, Wayne Watson wrote: >>> >>>> See Subject. I'm looking for something like the methods described in >>>> Meeus' Astro Formulae for Calculators. Something too that provides >>>> rotation matrices, calculations to find sidereal time, and az >>>> equal-distance projections. >>> >>> >> >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 >> feet "... humans'innate skills with >> numbers isn't much >> better than that of rats and >> dolphins." -- Stanislas Dehaene, >> neurosurgeon Web Page: >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "We're leaving you with a world that runs like clockwork. And the clock it runs like is a cuckoo clock." -- Frank Oppenheimer, physicist Web Page: From sierra_mtnview at sbcglobal.net Wed Dec 30 15:20:21 2009 From: sierra_mtnview at sbcglobal.net (Wayne Watson) Date: Wed, 30 Dec 2009 12:20:21 -0800 Subject: [AstroPy] Is There an AstroCalc Module? In-Reply-To: References: <4B38DF8E.3040901@sbcglobal.net> <8044925C-1661-4AF6-800E-64D2E3515EED@uw.edu> <4B38FA1D.2050009@sbcglobal.net> <4FEEB42C-4B53-4EC9-8293-200D4D3BA5CA@uw.edu> <4B3BA4E5.50500@sbcglobal.net> Message-ID: <4B3BB605.2050006@sbcglobal.net> What is PyPI? I unzipped the file, and searched for an html, but don't see any. I guess it's only at PyPI. Snap shot of my folder below this line. Russell Owen wrote: > There is an overview at PyPI and in an html doc that is part of the > source distro. Other than that, no...use the doc strings and the info > I sent you. > > -- Russell > > On Dec 30, 2009, at 11:07 AM, Wayne Watson wrote: > >> Before I install it, is there a document that summarizes what's in >> it? That is, gives a brief summary of each function? >> >> Russell Owen wrote: >>> The RO package is pure python so I only have a source code version >>> available. That is the one you want. >>> >>> I suggest you use "easy_install" or "pip" to install it. >>> >>> You can also install it by downloading it and running "setup.py >>> install" in the main directory--though it may require setuptools. >>> Once you have installed setuptools you have "easy_install" so you >>> might as well use that. (pip also requires setuptools -- nearly any >>> sort of installer does these days). >>> >>> Or if you wish to avoid setuptools then you can download the source >>> and copy or move the "RO" directory (/python/RO) into >>> your site-packages directory. I don't know where site-packages is on >>> Windows. >>> >>> Regards, >>> >>> -- Russell >>> >>> On Dec 28, 2009, at 10:34 AM, Wayne Watson wrote: >>> >>>> Hi, I'm on Python 2.5, Windows. Are any of the downloads on the >>>> link applicable to my situation? If I use it, where under >>>> c:/Python25 do I put it? Lib? >>>> >>>> Russell Owen wrote: >>>>> There is various software that will perform astronomical >>>>> transformations of time and position. I do not know what exists >>>>> for projections (other than any projections that might exist in >>>>> matplotlib). >>>>> >>>>> One option is RO.Astro >>>>> , which I >>>>> wrote. The routines are easy to use (see documentation in doc >>>>> strings) and the coordinate transformations are performed to high >>>>> accuracy. It is pure python (though it uses numpy) so it is >>>>> trivial to install and fully cross-platform, but not as fast as >>>>> some other options. >>>>> >>>>> Overview: >>>>> RO.Sph: handles computations in spherical coordinates (e.g. RA/Dec >>>>> to Az/Alt). RO.Sph.coordConv is the "do it all" routine. It also >>>>> has angSideAng, a routine to handle spherical geometry >>>>> computations, and routines to convert between spherical and >>>>> cartesian coordinates. >>>>> RO.Cnv: handles computations in cartesian coordinates; this is >>>>> where most of the real computations are performed >>>>> RO.Tm: handles various time computations >>>>> >>>>> >>>>> -- Russell >>>>> >>>>> On Dec 28, 2009, at 8:40 AM, Wayne Watson wrote: >>>>> >>>>>> See Subject. I'm looking for something like the methods described in >>>>>> Meeus' Astro Formulae for Calculators. Something too that provides >>>>>> rotation matrices, calculations to find sidereal time, and az >>>>>> equal-distance projections. >>>>> >>>>> >>>> >>>> -- >>>> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >>>> >>>> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >>>> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 >>>> feet "... humans'innate skills with >>>> numbers isn't much >>>> better than that of rats and >>>> dolphins." -- Stanislas Dehaene, >>>> neurosurgeon Web Page: >>>> >>> >>> >> >> -- >> Wayne Watson (Watson Adventures, Prop., Nevada City, CA) >> >> (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) >> Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 >> feet "We're leaving you with a world >> that runs like >> clockwork. And the clock it runs like is a cuckoo >> clock." -- Frank Oppenheimer, physicist >> Web Page: >> > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39? 15' 7" N, 121? 2' 32" W, 2700 feet "We're leaving you with a world that runs like clockwork. And the clock it runs like is a cuckoo clock." -- Frank Oppenheimer, physicist Web Page: