Does anyone know of a tracking application or program or some other software or existing source that will still produces or publishes equatorial crossing data for current satellites?
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone
EMike,
If you enjoy diving into code, you can use my very simple python script to derive this data. It's 100% free for any and all purposes. I wrote it specifically for educational purposes. Check out the code here: https://code.google.com/p/ge-satellite-tracker/
Also, see my blog posts from Feb 2012 regarding ARISSat-1. I generated all of my plots using the same concept: http://libjoe.blogspot.com/2012/02/arissat-1-analysis-eclipses-and.html
If you have any questions, let me know.
Joseph Armbruster
On Thu, Jul 31, 2014 at 10:51 PM, EMike McCardel [email protected] wrote:
Does anyone know of a tracking application or program or some other software or existing source that will still produces or publishes equatorial crossing data for current satellites?
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone _______________________________________________ Sent via [email protected]. 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
i8CVS posted the directions to calculate EQX and everything else needed to use an OSCARLATOR from Keplerian elements back in 2003.
http://www.amsat.org/amsat/archive/amsat-bb/200203/msg00749.html
I haven't done any programming in forever, but maybe I'll try to write a short program to automate those calculations at some point (unless someone already has).
73,
Paul, N8HM
On Thu, Jul 31, 2014 at 10:51 PM, EMike McCardel [email protected] wrote:
Does anyone know of a tracking application or program or some other software or existing source that will still produces or publishes equatorial crossing data for current satellites?
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone _______________________________________________ Sent via [email protected]. 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
You can easily find the times for equatorial crossing for ascending passes from the element set.
Consider Oscar 7
Satellite: AO-07 Catalog number: 07530 Epoch time: 14211.80120610 Element set: 27 Inclination: 101.4754 deg RA of node: 192.2023 deg Eccentricity: 0.0011666 Arg of perigee: 207.8798 deg Mean anomaly: 270.9717 deg Mean motion: 12.53605918 rev/day Decay rate: -2.2e-07 rev/day^2 Epoch rev: 81698 Checksum: 281
The epoch time is the reference time for that element set. It also happens to be the time for the ascending node (equatorial crossing North-to-South). In this case it is "14211.80120610" which comes out to the year 2014, day 211 and the hour comes out to 19.22 hours.. or approximately 19 hours, 13 minutes, 44 seconds.
Ignoring the decay rate, the next ascending node will be in one orbital period. You can get this by dividing the number of minutes in a day by the mean motion: 1440/12.53605918=114.869 minutes after the epoch time.
Getting the descending node is more problematic if the orbit is highly eccentric. In the case of Oscar 7, the eccentricity is small, and it is close enough to a circular orbit that it is reasonable to assert that the descending crossing of the equator is very close to 1/2 orbital period after the ascending node (unless your TLE's are more than a few days old).
Glen AA8C
On 08/01/2014 03:07 AM, Paul Stoetzer wrote:
i8CVS posted the directions to calculate EQX and everything else needed to use an OSCARLATOR from Keplerian elements back in 2003.
http://www.amsat.org/amsat/archive/amsat-bb/200203/msg00749.html
I haven't done any programming in forever, but maybe I'll try to write a short program to automate those calculations at some point (unless someone already has).
73,
Paul, N8HM
On Thu, Jul 31, 2014 at 10:51 PM, EMike McCardel [email protected] wrote:
Does anyone know of a tracking application or program or some other software or existing source that will still produces or publishes equatorial crossing data for current satellites?
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone _______________________________________________ Sent via [email protected]. 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 [email protected]. 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
Glen, Paul and Joseph,
Thank you for your replies. I am learning a lot here. My imagination has been captured by learning to use the Satellabe and OscarLocator prepping for my presentation on tracking satellites at the AMSAT Training Day during the ARRL Centennial. I also discovered a construct involving a globe offering a 3D rendition of of a pass. This is an interesting way to demonstrate how the earth moves independent of the orbit. I can't help but think that some of the analogue tools of the day still have relevancy.
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone
On Aug 1, 2014, at 11:53 AM, Glen Gardner [email protected] wrote:
You can easily find the times for equatorial crossing for ascending passes from the element set.
Consider Oscar 7
Satellite: AO-07 Catalog number: 07530 Epoch time: 14211.80120610 Element set: 27 Inclination: 101.4754 deg RA of node: 192.2023 deg Eccentricity: 0.0011666 Arg of perigee: 207.8798 deg Mean anomaly: 270.9717 deg Mean motion: 12.53605918 rev/day Decay rate: -2.2e-07 rev/day^2 Epoch rev: 81698 Checksum: 281
The epoch time is the reference time for that element set. It also happens to be the time for the ascending node (equatorial crossing North-to-South). In this case it is "14211.80120610" which comes out to the year 2014, day 211 and the hour comes out to 19.22 hours.. or approximately 19 hours, 13 minutes, 44 seconds.
Ignoring the decay rate, the next ascending node will be in one orbital period. You can get this by dividing the number of minutes in a day by the mean motion: 1440/12.53605918=114.869 minutes after the epoch time.
Getting the descending node is more problematic if the orbit is highly eccentric. In the case of Oscar 7, the eccentricity is small, and it is close enough to a circular orbit that it is reasonable to assert that the descending crossing of the equator is very close to 1/2 orbital period after the ascending node (unless your TLE's are more than a few days old).
Glen AA8C
On 08/01/2014 03:07 AM, Paul Stoetzer wrote: i8CVS posted the directions to calculate EQX and everything else needed to use an OSCARLATOR from Keplerian elements back in 2003.
http://www.amsat.org/amsat/archive/amsat-bb/200203/msg00749.html
I haven't done any programming in forever, but maybe I'll try to write a short program to automate those calculations at some point (unless someone already has).
73,
Paul, N8HM
On Thu, Jul 31, 2014 at 10:51 PM, EMike McCardel [email protected] wrote: Does anyone know of a tracking application or program or some other software or existing source that will still produces or publishes equatorial crossing data for current satellites?
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone _______________________________________________ Sent via [email protected]. 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 [email protected]. 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 [email protected]. 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
participants (4)
-
EMike McCardel -
Glen Gardner -
Joseph Armbruster -
Paul Stoetzer