24b0ac3700
For #406 , add Time constructors from datetimes
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This was previously an implicit power of `ts.utc()` which was more
difficult for users to find.
2020-07-17 09:41:48 -04:00
d23ce4e1ee
For #406 , mention more modern timezone sources
2020-07-17 08:18:50 -04:00
b8fdc4dc4a
For #407 , explain that open() does not re-download
2020-07-17 06:08:15 -04:00
5d17b96fcb
Lock in velocity accuracy with an actual test
2020-07-17 05:55:34 -04:00
3c5b869131
Fix order of operations in ITRF_to_GCRS2()
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Because two components of the position vector are used to finish
building the velocity vector, it was a mistake to rotate the position
vector using the M matrix until after the velocity vector has also been
built. This increases by almost two magnitudes the agreement between
Earth satellite reported velocities and the actual difference between
their successive positions.
2020-07-16 16:31:02 -04:00
d5736b1832
Fix docs: slight change in satellite numbers
2020-07-16 06:09:07 -04:00
aff3731cf7
Use JD whole + fraction when computing GMST1982
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This eliminates one source of noise as I dive into why Skyfield
satellite velocities do not hew as closely to actual satellite motion as
they do when the underlying sgp4 library is used alone.
2020-07-16 05:53:22 -04:00
d2b105d6a0
Extend two-float precision to how UT1 is stored
2020-07-15 06:24:48 -04:00
da2e1fd735
Make TEME→ITRF test 20,000 times more sensitive
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It turns out I was somehow being hamfisted in how I built the Julian
date to pass to `TEME_to_ITRF()` in the test. By building the Julian
date manually, without going through a `Time` object, I can produce far
more exactly the quantities specified in AIAA-2006-6753 Appendix C.
2020-07-14 15:44:55 -04:00
af622b7f69
Add another TODO item, for making API friendlier
2020-07-14 15:38:40 -04:00
87f4611030
Remove some old comment debris
2020-07-13 05:13:57 -04:00
72ff2c2348
For #402 , try describing each axis of ICRS
2020-07-09 21:09:29 -04:00
2c13217b05
Update Positions doc: we now do comets, asteroids
2020-07-09 20:45:44 -04:00
1e7a7a0b58
Update Circular 179 link, and save it just in case
2020-07-09 20:21:18 -04:00
43bb53036d
Remove old Keplerian library
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With thanks to its author, @hoylemd, for this early prototype!
2020-07-09 19:31:46 -04:00
4fb5e7a9f4
Fix a :doc: link in documentation
2020-07-09 19:31:06 -04:00
b4efc4f06a
Update changelog and declare 1.23
2020-07-09 15:11:05 -04:00
1bec4666f2
Fix CI: only run pyflakes if already installed
2020-07-09 15:02:52 -04:00
dbd2d3c9ec
Start running pyflakes locally again; and, fixes
2020-07-09 14:56:57 -04:00
fa8fdc2315
Remove internal round-trips through unit objects
2020-07-09 14:51:43 -04:00
3f2b8a6941
Have comet and minor planet orbits take GM as arg
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This replaces the flawed design where GM is a hidden parameter, which
would put Skyfield in a bad position when a higher precision estimate
for GM became available: Skyfield would have had to choose between
keeping the old value for compatibility (maybe with a way to supply an
updated value instead), or updating the value and suddenly having the
new version of Skyfield give different results. Instead, each user’s
program will now make explicit its choice of constant.
2020-07-09 14:18:09 -04:00
c39c67a051
Move all MPC-specific knowledge into "mpc" module
2020-07-09 11:30:54 -04:00
f8af2591c5
Document minor planet orbits; many tweaks
2020-07-08 06:26:51 -04:00
8a0a60fd6a
Sample script for filtering the MPCORB file
2020-07-07 21:05:24 -04:00
5f655a517e
Commit a copy of CometEls.txt for CI to use
2020-07-07 15:17:52 -04:00
b14185584e
Document how to generate a comet position
2020-07-07 14:15:04 -04:00
872583504c
Rewrite comet import with RE-powered CSV transform
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Nearly as fast as the previous “fast” version, but (a) this one never
gets the wrong values in the wrong columns, and (b) it returns the full
names instead of the awkward packed designations.
2020-07-07 13:42:58 -04:00
b254335063
Fix #395 by making Time objects hashable
2020-07-02 12:47:07 -04:00
d67462be78
Fix docstring of Geocentric to name GCRS, not ITRF
2020-07-01 13:53:24 -04:00
ba1172a0cc
Add some TODO items inspired by a Stack Overflow Q
2020-07-01 12:29:25 -04:00
a59e0d8796
Use packed designation for minor planet target
2020-06-17 16:06:47 -04:00
0249ff9c68
Move unpacking into a separate function
2020-06-17 15:59:52 -04:00
393deb3df6
Try unpacking comet designation automatically
2020-06-17 15:50:17 -04:00
f24edc2c61
Give comet objects a string target as well
2020-06-17 15:09:35 -04:00
8cf61540c6
Use minor planet name as its "target" value
2020-06-17 12:23:51 -04:00
77564f8b23
Fix an unused import
2020-06-17 11:11:51 -04:00
733185e07e
First successful test of a minor planet position!
2020-06-17 11:06:11 -04:00
f9e854c029
Expand test to both comet import routines
2020-06-16 16:28:03 -04:00
32f4a86cf5
Also check comet distance in test
2020-06-16 15:37:49 -04:00
56d7656cbf
Also rotate velocity of Kepler position
2020-06-16 15:33:20 -04:00
ac19f76593
Factor ecliptic matrix building into a function
2020-06-16 15:17:03 -04:00
7b93ce0fc8
Switch test away from deprecated ".ix", to fix CI
2020-06-16 12:52:54 -04:00
c1904851dc
First tested round-trip of a comet position!
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This also starts simplifying the keplerlib itself.
2020-06-16 12:44:48 -04:00
d4e83ce822
Rename the “horizons/” directory to “authorities/”
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And add the directory’s first non-HORIZONS file; hence, the name change.
2020-06-16 12:38:15 -04:00
59b7319724
Remove some completed TODO items
2020-06-16 09:57:29 -04:00
40675178ac
Explain: it’s more efficient to loop over strings
2020-06-16 09:52:50 -04:00
89ed1cb824
Add time array “for” loops in Date arrays section
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For #390 . There is a single `for` loop illustrated in the previous
section, but users not concerned with leap seconds might easily skip
that whole topic; so let’s also include some `for` loops in the section
on date arrays, where they certainly belong.
2020-06-16 08:07:01 -04:00
8e03c8200c
Add changelog entry about TLE behavior
2020-06-16 07:26:42 -04:00
94a307a9fa
For #391 , set a very low bar for satellite names
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Hopefully not too many users will get nonsense text as a result, and
hopefully those that do will see the option letting them avoid it.
2020-06-15 22:46:37 -04:00
9fe659a280
Add "spktype21" to dependencies needed under CI
2020-06-15 18:11:38 -04:00
Brandon Rhodes