Posts by revent

by revent
25.04.2008, 06:29
Forum: Celestia Users
Topic: Antialiasing Problem
Replies: 31
Views: 8103

Re: Antialiasing Problem

Easiest it to open the file once in Wordpad, then immediately save it with no changes. That way, next time you doubleclick on the file (and it opens in Notepad) it will be correct in Notepad.
by revent
23.04.2008, 11:11
Forum: Celestia Users
Topic: Antialiasing Problem
Replies: 31
Views: 8103

Re: Antialiasing Problem

Make sure you have enabled mipmapping and anisotropic filtering also.

BTW, blurring the edges of objects is really only a side effect of antialiasing. When you really need it is if you're seeing odd-looking moire patterns in the middle of a object that aren't in the texture.
by revent
23.04.2008, 10:02
Forum: Celestia Users
Topic: Antialiasing Problem
Replies: 31
Views: 8103

Re: Antialiasing Problem

It's not a problem with antialiasing, it's that you're looking at something where antialiasing has no effect. Unless you are actually /seeing/ aliasing, antialiasing does nothing. Go look at http://en.wikipedia.org/wiki/Antialiasing For that matter, your images are so lo-rez that any differnce would...
by revent
22.04.2008, 00:13
Forum: Celestia Users
Topic: data output for other apps?
Replies: 2
Views: 2020

Re: data output for other apps?

No, that's not supported in Celestia.
by revent
21.04.2008, 22:37
Forum: Physics and Astronomy
Topic: Lunar Orbit Precession Tutorial?
Replies: 1
Views: 2343

Re: Lunar Orbit Precession Tutorial?

Draconic month? (ruffles around Wikipedia) Nodical month sounds more familiar. :) The Nodical month is just another way of measuring the lunar orbit. It's the average length of time between crossings of the ascending node, i.e. between times the moon crosses the ecliptic while moving northward. I th...
by revent
21.04.2008, 21:30
Forum: Physics and Astronomy
Topic: space craft change speed as they swing by Earth
Replies: 2
Views: 2260

Re: space craft change speed as they swing by Earth

I've kinda suspected for a long time that the 'Pioneer Anomaly' was due to disregarding the effects of the (admittedly minute) change in rotational inertia (and rotational kinetic energy) of the solar system as the probes move outward. The same effect would occur during a close approach, but would g...
by revent
21.04.2008, 20:48
Forum: Ideas & News
Topic: SPICE rotation models
Replies: 23
Views: 16541

Re: SPICE rotation models

Just to make sure I understand this clearly, since there's some confusion between the 'types' of Spice kernels and their filenames.. .bsp files are SPK kernels, what we're used to for ephemerides your 'tpc' file is a text PCK kernel, for 'target' parameters and orientation your 'tf' file is a text F...
by revent
20.04.2008, 08:21
Forum: Utilities
Topic: Useful Helpers Repository (Programs/Spreadsheets etc.)
Replies: 35
Views: 29284

Re: Converting Galactic Coordinates to Equitorial J2000 coordina

Here are some links to an alltime favorite: Coordinate transformations. A nice usefull programm, that can convert nearly everything. It is called "Coordinate Conversions in Astronomy" or "CooC". That programm is also able to batch convert, by giving it a preformatted CSV file fo...
by revent
20.04.2008, 08:06
Forum: Add-on development
Topic: Pseudo Globular Clusters
Replies: 20
Views: 5218

Re: Pseudo Globular Clusters

It isn?t working.I don?t know what format it have to be able to use,but simply saving in .txt format and putting in extras don?t works.Maybe there is a .ssc lacking.I have a M4.ssc and M4.dsc from an old addon of Selden,but Celestia didn?t recognizes it. Daniel, the filename has to end with '.dsc' ...
by revent
20.04.2008, 07:37
Forum: Celestia Users
Topic: Ephemeris Accuracy
Replies: 29
Views: 13395

Re:

The "period "needs to be extended this shows the orbit from 01-01-2007 until 2049. I still don't understand why the orbit isn't drawn prior to 2007, although by running time back Voyager2 orbit can be tracked so it would appear that all the orbit info is in the file.????? Actually, the tr...
by revent
18.04.2008, 11:19
Forum: Celestia Users
Topic: Pluto's orbit
Replies: 18
Views: 6671

Re: Re:

FYI, the pluto orbit in the Celestia distribution is pretty bogus anyhow. VSOP87 is based on DE200, and the DE200 Pluto orbit wasn't fit to observations. VSOP87 doesn't include an orbit for Pluto, so we're using a different theory. It's still not very good, however. If you (or anyone) knows of a go...
by revent
18.04.2008, 03:45
Forum: Celestia Users
Topic: Opinions: dwarf planets and minor moons
Replies: 48
Views: 15412

Re: Opinions: dwarf planets and minor moons

⋅ While the existing data files may contradict this, I'd personally like to define "minor-moon" as a moon without an official name (i.e. numbered moons). That may provide a more concrete definition than currently proposed. As I commented elsewhere a little while ago, I'd suggest...
by revent
18.04.2008, 03:28
Forum: Celestia Users
Topic: Celestia Venus Upside down? or is it me?
Replies: 14
Views: 4419

Re: Celestia Venus Upside down? or is it me?

I wonder when I look at Venus Express UV images where you cant see the ground as reference points, what system are they using? The ESA's website describes Venus as a 'clockwise, or retrograde' rotator, which would imply that they define the north pole wrt the celestial sphere, not rotation. They al...
by revent
18.04.2008, 02:33
Forum: Celestia Users
Topic: Is Amalthea considered a minor moon?
Replies: 28
Views: 6772

Re: Is Amalthea considered a minor moon?

I would think the logical criteria for separating 'minor' and 'major' moons would be whether or not the moon in question is massive enough that it's gravitational effects need to be considered when calculating the orbits of the other moons.
by revent
07.03.2008, 03:49
Forum: Celestia Users
Topic: Pluto's orbit
Replies: 18
Views: 6671

Re: Pluto's orbit

FYI, the pluto orbit in the Celestia distribution is pretty bogus anyhow. VSOP87 is based on DE200, and the DE200 Pluto orbit wasn't fit to observations.
by revent
07.03.2008, 03:28
Forum: Celestia Users
Topic: Ephemeris Accuracy
Replies: 29
Views: 13395

Re: Ephemeris Accuracy

I think the orbital elements of most asteroids and comets can be updated with much more accurate numbers from NASA's Horizons system, but question is at what epoch do you generate them, since they're more accurate at a time you know it passes at a known distance from another body. I.e. you know tha...
by revent
07.03.2008, 01:21
Forum: Celestia Users
Topic: Ephemeris Accuracy
Replies: 29
Views: 13395

New version of JPL ephemeris

CAP-Team, What are you trying to say? That that's a good value or bad value? Which version of Celestia did you use? Celestia v1.5.0 has had many improvements in the way it calculates trajectories. The most accurate trajectories will be seen if you configure Celestia to use JPL's DE405 or DE406 ephe...
by revent
08.12.2007, 01:06
Forum: Ideas & News
Topic: SPICE
Replies: 62
Views: 47857

Re: SPICE

[...] I figure that the kernel date should be close to the respective mission configuration. But I can't even read uniquely what e.g. 50825R_SCPSE_05186_05205.bsp is going to mean... Ran across this message again, and I was actually just looking at the Cassini spice files earlier. The files that PD...
by revent
14.10.2007, 20:48
Forum: Physics and Astronomy
Topic: Quick question
Replies: 3
Views: 2414

Re: Quick question

I did a SIMBAD search on a star and under the 'flux' section, it told me: B 13.158 V 13.524 I 13.894 U 11.894 R 13.689 J 14.332 H 14.490 K 14.548 Now, if I understand correctly, V is visual magnitude. Are B, I, U, R, etc other wavelengths (IR, Ultraviolet, etc)? If so, what do each of them correspo...

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