Need some help - coordinate systems

[Phil Smith]

Hey guys,
I'm in the process of writing a trajectory simulation software (on c++, using Runge-Kutta RK4 method) and now it's time to go beyond "Launch site coordinate system".. I spent a few days figuring out converting them to Geocentric coordinates, but maybe there are some good books on this topic and not re-inventing the wheel one more time? Because these transformation matrices aren't new at all.

PS. I found one, but it costs up to 200 bucks :facepalm::blink:-
http://www.amazon.com/Aerospace-Coo...ue&ref_=ox_sc_sfl_title_4&smid=A125ZX544T82QX

I appreciate any help,
Thanks!

 

[Urwumpe]

I spent a few days figuring out converting them to Geocentric coordinates, but maybe there are some good books on this topic and not re-inventing the wheel one more time?

What about starting with WGS 84, the coordinate system used by GPS

http://earth-info.nga.mil/GandG/publications/tr8350.2/tr8350_2.html

 

[Phil Smith]

What about starting with WGS 84, the coordinate system used by GPS

http://earth-info.nga.mil/GandG/publications/tr8350.2/tr8350_2.html

Thank you, Urwumpe! Gotta print & read this stuff :thumbup:

PS. By the way, I found some interesting books on this topic, I'll post em later in the "Space PDF Collection" thread

 

[Quick_Nick]

Regarding coordinate transformations, I've recently referenced this Appendix of a book on GPS and inertial navigation:
http://onlinelibrary.wiley.com/doi/10.1002/0471200719.app0c/pdf

I did notice a typo in the RPY to NED matrix (the only one I needed) so be careful.

 

[Col_Klonk]

Regarding coordinate transformations, I've recently referenced this Appendix of a book on GPS and inertial navigation:
http://onlinelibrary.wiley.com/doi/10.1002/0471200719.app0c/pdf

I did notice a typo in the RPY to NED matrix (the only one I needed) so be careful.

Nice.. thanks
:thumbup:

 

[Phil Smith]

Regarding coordinate transformations, I've recently referenced this Appendix of a book on GPS and inertial navigation:
http://onlinelibrary.wiley.com/doi/10.1002/0471200719.app0c/pdf

I did notice a typo in the RPY to NED matrix (the only one I needed) so be careful.

Thank you much!
So what type of typo? they just wrote a +/- sign somewhere incorrectly or something worse?

 

[Quick_Nick]

Thank you much!
So what type of typo? they just wrote a +/- sign somewhere incorrectly or something worse?

They represented sine and cosine with a big S or C. The matrix is a bunch of big Ss and Cs with subscripts representing what's operated on (roll, pitch, yaw).
Instead of S or C, one of the elements says P! (Never heard of a 'P' trig function!) If you multiply out the three component matrices yourself, you find that they meant to put C.

It's a minor thing there, but it would make me be alert to other possible errata.

Edit: In fact, Amazon reviews report numerous errors in this book! Hopefully it helps though.

 

[Phil Smith]

Roger understand, thanks!
As far I can see, it's a first edition of this book, but I found second edition (2007) -
http://www.amazon.com/Positioning-S...Systems,+Inertial+Navigation,+and+Integration
and, it seems, it's been written more accurate.
Take a look:
http://read.pudn.com/downloads165/e...stems_Inertial_Navigation_and_Integration.pdf

 

[Quick_Nick]

Roger understand, thanks!
As far I can see, it's a first edition of this book, but I found second edition (2007) -
http://www.amazon.com/Positioning-S...Systems,+Inertial+Navigation,+and+Integration
and, it seems, it's been written more accurate.
Take a look:
http://read.pudn.com/downloads165/e...stems_Inertial_Navigation_and_Integration.pdf

It still has the error I mentioned, for whatever that's worth (page 478 of book; page 507 of PDF - first element of matrix C.107).
Pretty cool that you found the full text though.