Hi,But if you enable the "Visual helpers", the Planetarium mode -> Target Equator line doesn't pass over the equator.
For the .cfg files, units are radians not degrees.if you use Obliquity = 177.6 (a reasonably accurate value), the spin axis seems to be about 100 deg (the ecliptic blue line is almost vertical instead of horizontal).
Here's my rather clunky manually work-intensive procedure:is there a procedure you can recommend to create the elevation data for Orbiter?
I'm probably misinterpreting the meaning of the lines, but I think there's something strange. I'll do some testing...looks ok to me. Checked by tracking equatorial feature.
Ooops! You're right.For the .cfg files, units are radians not degrees.
Thank you. I already read PlanetTextures.pdf, it's the reason I asked here.Here's my rather clunky manually work-intensive procedure:
or try googling for "orbiter forum elevation". Also, have a look in Orbiter Doc/PlanetTextures.pdf.
The first strange thing is that that line is purple in my installation (Orbiter 2016).The visual helper "Target Equator" green line is a projection of the target planet's equator onto the Celestial sphere, as far as I know.
Since I use SPICE to do all the calculation, I can calculate and verify anything, but the problem is to understand the exact meaning of those parameters in Orbiter.For a more accurate orientation of Bennu, you may want to figure out the axis LAN parameter in the .cfg file (currently set to LAN = 0 ).
The Wikipedia entry for Bennu gives RightAscension and Declination of the N.Pole, so it can be calculated from that. (I might have a go at some point).
Also, the rotation offset needs to be set (currently set to SidRotOffset = 0).
You might be able to do that if you have an image of Bennu with a time stamp from the spacecraft.
You can bet!Do let me know if you figure out those parameters!
You're right! With the default graphics it looks good.Hi,
I have a hunch you're using the D3D9 graphics client for Orbiter, yes?
For some reason the "Target Equator" display in D3D9 is a purple line and always shows along the Celestial sphere equator (whatever the target is). Try using the default Orbiter2016 graphics - the line is green and looks like it is in the correct place relative to Bennu (to me anyway!).
With SPICE I obtain the "exact" location of the bodies, but if I also want a correct Bennu prime meridian location, I also need to bother with those parameters (I remember the same for Pluto/Charon synchronism).If you're using SPICE to set the orbit and orientation, I guess you won't need to bother with those parameters in the .cfg file?
The values are 214.55 m and 289.351 m, but if we consider the .bmp image, those 8-bit converted altitudes become 214.404 and 289.205.FYI, from those red/blue height maps, I estimated the maximum elevation to be 287m, and minimum 215m, and processed the image accordingly. This may not be accurate enough for you. Do you have more accurate max./min. elevation values?
Thanks a lotNot much work to re-do those values and run the ele2png.exe
I'll have another go with more accurate max/min values.
At step 2 I read that you scale an image to several resolution; isn't it better to have all the necessary .bmp without having to scale them?Here's my rather clunky manually work-intensive procedure:
At step 2 I read that you scale an image to several resolution; isn't it better to have all the necessary .bmp without having to scale them?
If I correctly understand the doc "PlanetTextures.pdf" page 9, the elevation resolution is 1 m.Just working on a more accurate elevation model for Bennu - I think we are up against the maximum resolution that ele2png.exe can process(I believe it uses integers for max./min. values). I have got the accuracy down to ~0.1m at max/min points.
Very good!I think that's the best I can do! Will upload soon.
The most updated values used by NAIF are: RA= 85.4567, DE= -60.3574: https://naif.jpl.nasa.gov/pub/naif/ORX/kernels/pck/bennu_v14.tpcI'm just looking at the rotation axis parameters.
The Wikipedia RA/Dec for N.Pole implies an obliquity of ~173.32deg. relative to ecliptic. Do we believe that?