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 Incoming gamma radiation 
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
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predictor.png
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color codes:
Yellow dot: SNAPSHOT satellite body. Height of dot proportional to satellite elevation ie 90 degrees = 1
Cyan: (pale blue) LND7311 700V outdoors in open top lead box
Grey: LND714 500V in window frame facing East (exposed on outdoor end of tube)
Blue: new LND714 500V outdoor in open top lead box (replaces LND 7311) short run due to thunderstorm


Tue Jun 28, 2016 7:22 am
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
just discovered that the SD card was hanging the system...and now it's
going to rain again...argggggh


Tue Jun 28, 2016 9:09 am
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Joined: Sat Feb 01, 2014 3:46 pm
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File comment: Gamma spikes vs SNAPSHOT orbit track
predictor.png
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Just when I was asking myself " where's the pattern"? I found it!


Tue Jun 28, 2016 8:06 pm
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Joined: Sat Feb 01, 2014 3:46 pm
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File comment: Update Gamma spikes vs SNAPSHOT Satellite orbit track
predictor.png
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LND7311 data removed for clarity
Y axis is now scaled so that elevations are divided by 100, ie 90 degrees will appear at the 0.9 tick.
To request a copy of the raw data please email me at peter@well.com


Wed Jun 29, 2016 9:57 pm
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
With help from Chip at the N2YO satellite tracking website I started pulling debris data for SNAPSHOT followed by a prediction sheet for 10 days ahead for each numbered fragment. The plot below shows the tracks for about 50 out of 160 that have published orbital elements. This is from the NASA database with our blue dot up-facing gamma tube. I am now visually tagging each fragment if it is in sync with the radiation peak in timing, and falls in the 75-90 degree elevation window of the lead box.
Attachment:
debris.png
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Sat Jul 02, 2016 5:48 pm
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Joined: Sat Feb 01, 2014 3:46 pm
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shielded tube test.png
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Trial analysis is now in progress. Looking visually at orbit peak elevations vs gamma peak height using the software cursor to line up on the dots. Already have several hits. The NASA data is on their database and is an API that has to be ASCII screen grabs instead of downloads so it will take a while to collect all of the orbital elements for the rest of the debris. Once I get the flow of the analysis, it will be time to write code to process and generate new graphics suitable for framing... :!:


Sun Jul 03, 2016 3:32 pm
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Joined: Fri Jul 03, 2015 7:04 pm
Posts: 147
Location: Toronto Canada
That's good thinking digging up the predictions for all the SNAPSHOT debris. It might explain why the original orbital predictions don't always line up with your higher readings. The main satellite body takes approximately 3 minutes to travel its 1300 km overhead path. Do all the debris pieces remain in a "cloud" near the main body? That is, are they passing overhead within the same time window? Assuming all the debris is highly radioactive, it would extend the 3 minute window (if the debris is ahead or behind the main body), or extend the east-west strip (if they are beside the main body). The idea is that it should have an apparently larger size, but still have predictable passes above a shielded detector.

The main peaks in your data show a clear 24 hour pattern. Looking at this satellite's orbit, and assuming a debris cloud not too large, one would expect the gaps (< 70 degrees elevation for passes) to follow a kind of a beating pattern where the 111 minute orbit and our 24 hour rotation results in a longer term gap width pattern something like this: 24, 12, 24, 24, 72, 24, 24, 12, 24, 24, 72, 24, etc. Here is the next 10 day's orbit marked with red dots when passing over my location at 70 degrees or more elevation:
ImageImage

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http://netc.com/chart/view.php?n=1%3A77D9CCCA.5 Toronto, Ontario, Canada SBM-20 indoors


Sun Jul 03, 2016 9:23 pm
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
Bert, you have a knack for this like no other!


Mon Jul 04, 2016 4:24 pm
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
NORAD number on bottom, Becquerel intensity on left axis. We can now see the individual chunks within several well defined clouds. A list of the chunks with calculated emission intensity is in process.

This is the complete database minus a handful of undefined objects that may be classified.
The main satellite body is #1314 on the far left.
Attachment:
File comment: NORAD number vs Becquerls
NORBQ-1.JPG
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Tue Jul 05, 2016 8:25 am
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Joined: Sat Feb 01, 2014 3:46 pm
Posts: 47
One question we needed to answer is do we really need a shielded tube pointing up? This graph shows the results between the two LND714 GM tubes in use, one in the window frame and the other in a lead box with no top, physically selecting orbit peak elevations above 70 degrees.
The top plot is the shielded tube, middle plot is in the window frame, using software to only show orbit peaks 70 degrees and over. The bottom plot uses the software to select only orbit peaks between 30 and 70 degrees. Conclusion is not much difference. We can most likely use older NETC data to compare results successfully.

Attachment:
File comment: Comparison of detector setups and acceptance angle constraints
COMPAR.JPG
COMPAR.JPG [ 130.92 KiB | Viewed 24829 times ]


Tue Jul 05, 2016 12:33 pm
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