Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Orbital elements in JSON output not correctly normalized into correct range #49

Closed
talister opened this issue Aug 17, 2023 · 3 comments
Closed

Comments

@talister
Copy link

While fitting 2023 PC, I noticed a discrepancy in the normalization of the mean anomaly M between the elements.txt, which was correctly in the range of 0...360 degrees and the value in the elements.json which wasn't.
elements.txt:

Orbital elements:  2023 PC
   Perihelion 2023 Nov 18.166035 +/- 0.0107246 TT =  3:59:05 (JD 2460266.666035)
Epoch 2023 Aug 17.0 TT = JDT 2460173.5   Earth MOID: 0.0313   Ve: 0.0980
M 265.36145981 +/- 0.0118074        (J2000 ecliptic)          Find_Orb
n   1.01580516 +/- 9.82149e-6       Peri.  311.44475 +/- 0.0027232
a   0.98008205 +/- 6.31727e-6       Node   126.07916 +/- 0.0005508
e   0.1829179 +/- 8.47122e-5        Incl.    5.58480 +/- 0.0032467
P   0.97/354.39d           H 24.6   G  0.15   U  5.0  
q 0.80080746 +/- 7.78775e-5    Q 1.15935663 +/- 9.04761e-5
34 of 45 observations 2023 July 10-Aug. 10; mean residual 0".22

elements.json (relevant segment only, MOIDS trimmed):

  "elements":
  {
    "central body": "Sun",
    "epoch":  2460173.50000000,
    "M": -94.63854019, "M sigma": 0.0118074,
    "n":   1.01580517, "n sigma": 9.82149e-6,
    "a":   0.98008205, "a sigma": 6.31727e-6,
    "e":   0.18291793, "e sigma": 8.47122e-5,
    "q":   0.80080747, "q sigma": 7.78775e-5,
    "Q":   1.15935664, "Q sigma": 9.04761e-5,
    "i":   5.58480168, "i sigma": 0.0032467,
    "arg_per":  311.44475676, "arg_per sigma":  0.0027232,
    "asc_node": 126.07916128, "asc_node sigma": 0.0005508,
    "Tp": 2460266.66603521, "Tp sigma": 0.0107246,
    "H":   0.15,
  },

Files attached (JSON file renamed to elements_json.txt since github doesn't allow upload of that type)
elements.txt
elements_json.txt

@Bill-Gray
Copy link
Owner

Hi Tim - this is something that I fixed a while back in the source code. I think you're running a version that's at least three years old. (If you hit '.', you'll get some data that includes the version date.)

I do now notice that the Windows .exes on the site are now about a year old. So they'll fix this bug, but I really ought to post an update; various things have been improved/fixed since then.

Unfortunately, I'm currently in Tucson at CSS. I won't be able to actually do it until I get home very late Saturday. Sometime Sunday, I should be able to build the Windows .exes, put together notes on what's changed (quite a bit, actually), and put a note on the Find_Orb users list. But the version already on the site will at least fix this problem.

@talister
Copy link
Author

I do apologize, I had done a fresh git checkout and make && make install so I thought I had the newest version but I discovered that the make install installed to a different place and the version I was picking up in $PATH was indeed from 2019. I have verified that the new version does correctly normalize the values.
I'll leave this Issue for you to close as/when you see fit

@Bill-Gray
Copy link
Owner

Hi Tim -- no worries, just as well to nudge me on the elderly Windows .exes...

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants