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orbital elements
On Feb 23, 7:07*pm, "U. N. McGregor" wrote:
How difficult is it to read this and understand it? *Is it written for engineers and scientists etc.? Remember , I am an amateur with limited math skills. I don't think that determining orbital elements from observations is described in too many places except in textbooks of celestial mechanics, which, of course, are aimed at stretching the brains of students rather than giving them pat cookbook formulae, and so this sort of thing will usually be available in a form that requires a lot of math to understand. But I see some people on this thread have been able to provide helpful answers. |
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orbital elements
On Feb 23, 5:31*pm, Llanzlan Klazmon wrote:
On Feb 24, 1:03*pm, "U. N. McGregor" wrote: Where can I find concise directions on how to determine orbital elements. All I ever see on the internet is description about what they are and mean but never the way to actually do that type of calculation. http://www.projectpluto.com/find_orb.htm#gauss Ah, I looked up and found that http://www.projectpluto.com/find_orb.htm is a page about software that does orbit determination. The page doesn't itself explain the algorithm, but gives references to a coupleof books. John Savard |
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orbital elements
On Feb 24, 2:04*am, Martin Brown
wrote: If you want to do your own orbit determinations rather than derive the equations from scratch then take a look at Project Plutos FindOrb. And there's a link from there - didn't work, had to use Google - to another program, http://adams.dm.unipi.it/~orbmaint/orbfit/ of which source code in FORTRAN is available, so the mysteries of orbit determination can be plumbed that way. John Savard |
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orbital elements
On Tue, 24 Feb 2009 00:03:41 GMT, "U. N. McGregor"
wrote: Where can I find concise directions on how to determine orbital elements. All I ever see on the internet is description about what they are and mean but never the way to actually do that type of calculation. I've found _Methods of Orbit Determination for the Micro Computer_, by Dan Boulet, to be the best _practical_ book on orbital dynamics (by far). It briefly covers history and derivations, but is strongly focused on practical math and algorithms. It's available at http://www.willbell.com/math/mc10.htm . _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
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orbital elements
Chris L Peterson wrote:
On Tue, 24 Feb 2009 03:30:14 GMT, Golden California Girls wrote: It can't be calculated without calculus math skills. I do orbital analysis all the time, and I never use calculus. You only need that if you want to derive the equations. Just determining orbital elements from observations requires nothing more than vector algebra. It only requires search engine and data entry skills. Free software is out there to do the computation, but it doesn't leave one with any understanding of what is going on. |
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orbital elements
Ok group thanks. As someone who wants to make observations of at least NEO's , I understand that carefully determining the changes in RA and DEC relative to known star positions is the first step. What is the least quality of CCD or CMOS digital camera is needed to take photos of orbits? What is the best what is the best way to determine good RA and DEC measures? "Chris L Peterson" wrote in message ... On Tue, 24 Feb 2009 00:03:41 GMT, "U. N. McGregor" wrote: Where can I find concise directions on how to determine orbital elements. All I ever see on the internet is description about what they are and mean but never the way to actually do that type of calculation. I've found _Methods of Orbit Determination for the Micro Computer_, by Dan Boulet, to be the best _practical_ book on orbital dynamics (by far). It briefly covers history and derivations, but is strongly focused on practical math and algorithms. It's available at http://www.willbell.com/math/mc10.htm . _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
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orbital elements
On Feb 25, 8:32*am, "U. N. McGregor" wrote:
Ok group thanks. *As someone who wants to make observations of at least NEO's , I understand that carefully determining the changes in RA and DEC relative to known star positions is the first step. What is the least quality of CCD or CMOS digital camera is needed to take photos of orbits? What is the best what is the best way to determine good RA and DEC measures? I suppose by reference to star/stars in the same image of known RA and DEC. You have to assume that the pros like the ESA Hipparchos team have done their job properly. |
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orbital elements
On Tue, 24 Feb 2009 19:32:09 GMT, "U. N. McGregor"
wrote: Ok group thanks. As someone who wants to make observations of at least NEO's , I understand that carefully determining the changes in RA and DEC relative to known star positions is the first step. What is the least quality of CCD or CMOS digital camera is needed to take photos of orbits? That's a difficult question to answer. It depends on the brightness of the NEOs you expect to detect, and on the degree of accuracy you want to achieve. With an ordinary DSLR you can certainly do some acceptable work, even though you are limited by camera noise and the color sensor. If you want to do really accurate work, however, you want a cooled, B&W CCD camera specifically designed for long exposure astroimaging. What is the best what is the best way to determine good RA and DEC measures? You need to use plate solving software. This analyzes an image, determines the positions of all the stars and compares them to catalog positions. You can readily get sub-arcsecond positions for asteroids this way. I use a program called Pinpoint. There is also software built into TheSky/CCDSoft, as well as several programs that are cheap or free. It is important to pick your reference catalogs carefully if you want the best results- there is a balance between the depth of the catalog (more stars is good), and the accuracy of the stellar positions (some rich catalogs are not very accurate). _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
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orbital elements
On Tue, 24 Feb 2009 19:32:09 GMT, "U. N. McGregor"
wrote: Ok group thanks. As someone who wants to make observations of at least NEO's , I understand that carefully determining the changes in RA and DEC relative to known star positions is the first step. What is the least quality of CCD or CMOS digital camera is needed to take photos of orbits? What is the best what is the best way to determine good RA and DEC measures? You want to get a telescope and imager that has a large enough field to have sufficient reference stars. A monochrome detector also is better than a one-shot color camera. The Handbook of Astronomical Image Processing from Willmann-Bell also includes AIP4WIN software, which does astrometry (finding positions from images). It is a decent book with practical information. University textbooks on spherical astronomy will have the heavy duty math. Bud |
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On Feb 24, 7:32*pm, "U. N. McGregor" wrote:
Ok group thanks. *As someone who wants to make observations of at least NEO's , I understand that carefully determining the changes in RA and DEC relative to known star positions is the first step. What is the least quality of CCD or CMOS digital camera is needed to take photos of orbits? What is the best what is the best way to determine good RA and DEC measures? Ra/Dec effectively ignores the Earth's orbital elements and runs everything off axial coordinates,the worse part is that it does so within the equable 365/366 day calendar system. If you are an astrophotgrapher who is snap happy working off the astrologiccal Ra/Dec system then it is a great convenience as as the forground objects such as the moon,planets,comets are pasted on to the celestial background like ornaments on a rotating christmas tree. The original astronomers,both geocentric and heliocentric,distinguished the motions of the planets AGAINST the stellar background whereas empiricists beginning with Newton, was working off Flamsteed's newly invented Equatorial Coordinate System and its 'predictive' positional nature based on the motion of the planets WITH the stellar background. The empirical 'predictions' therefore contain the original astrological framework that Flamsteed introduced to the daily rotation and orbital motion of the Earth.Wasnt to see what it looks like - http://www.youtube.com/watch?v=XTTDWhky9HY If you want orbital elements then start with the Earth and the specific way it orbits the Sun otherwise you will be nothing more than an astrologer with a magnification habit rather than an astronomer. "Chris L Peterson" wrote in messagenews:r248q45fqrjph7lcne1evkqae3d2uhgi6u@4ax .com... On Tue, 24 Feb 2009 00:03:41 GMT, "U. N. McGregor" wrote: Where can I find concise directions on how to determine orbital elements. All I ever see on the internet is description about what they are and mean but never the way to actually do that type of calculation. I've found _Methods of Orbit Determination for the Micro Computer_, by Dan Boulet, to be the best _practical_ book on orbital dynamics (by far). It briefly covers history and derivations, but is strongly focused on practical math and algorithms. It's available at http://www.willbell.com/math/mc10.htm. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com- Hide quoted text - - Show quoted text - |
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