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Author Topic: Split LOS in P23  (Read 6883 times)
abr35
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« on: July 04, 2011, 06:42:47 PM »

I'm trying to get a wiki article up on each group of vAGC programs. (One article covering P11, 17, another on P20, 21, 22, 23, 27 and etc). This will probably take some time b/c I'm going to be pretty busy in the next couple months. First, could someone supply me with an Apollo 8 scenario in cislunar space and another in lunar orbit? I need to play with P23, and P22 in lunar orbit has a slightly different procedure.

Second: I was testing P23 in earth orbit. The blinking SLOS is annoying at best when the earth takes up that much of the FOV  ROTFL Is there an alternate way to use the split line of sight? Thanks!
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eddievhfan1984
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« Reply #1 on: July 05, 2011, 08:21:34 AM »

I think that's pretty much it. If Orbiter could simulate split viewing windows like even Microsoft Flight Simulator could, that might help. But I found I could use it just fine.
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meik84
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« Reply #2 on: July 05, 2011, 09:10:09 AM »

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First, could someone supply me with an Apollo 8 scenario in cislunar space and another in lunar orbit?
You're a lucky guy Happy: I'm flying Apollo 8 at the moment to see in how far we can follow the real flightplan. Cislunar's below. W-matrix has already been initialised as said here http://history.nasa.gov/ap08fj/03day1_green_sep.htm at 03:46:31. I'm using Jim Lovell's horizon altitude (18.2 km), as described here http://history.nasa.gov/ap08fj/05day1_black.htm at 017:25:16. Seems to work, though I don't get all balls in both registers of N49, maybe due to this awkward SLOS/LLOS flickering. Yuck! A tip: you'd better use the SCS in min imp for the sightings -the min imp controller of the CMC tends to clip commands. SCS min imp does the same and is much more convenient -one hand for the sextant, the other for the RHC. Wink
P22 is a good question. I'm not in lunar orbit yet, so I can't tell. If you want to fly it by yourself, LTMFD already contains data for a lunar orbit which is at least similar to Apollo 8's (especially INC and LAN are at least near the original ones...).

* Apollo 8 at 04_54_XX.scn (79.46 KB - downloaded 142 times.)
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abr35
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« Reply #3 on: July 06, 2011, 07:43:17 PM »

To start I was getting around +00520 in Noun 49. Updated the state vector for the second try. I didn't get all balls, but managed to get four balls 3, so the program seems to work well enough. Looking at previous posts on the forum, people seemed to complain about it always giving all balls, so I'm glad it's now doing what it's supposed to. The flickering seems to get less annoying as you get out into deep space. Maybe the OVP people can find us away to superimpose images one day. P10s and P20s should be on the wiki soon.
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meik84
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« Reply #4 on: July 07, 2011, 08:14:45 AM »

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Looking at previous posts on the forum, people seemed to complain about it always giving all balls, so I'm glad it's now doing what it's supposed to.
That was due to the fact that the w-matrix was uninitialized, so that it contained only 0's. As far as I understand, the vector from the star/horizont mark is multiplied with the w-matrix to get the dV and dR for the SV update -and something multiplied with 0 is always 0... Wink
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I didn't get all balls, but managed to get four balls 3, so the program seems to work well enough.
AFAIK Jim Lovell's marks got more accurate the further away they were from earth. I guess that from a longer distance the fuzziness of earth's horizont is less, so that the LLOS point is better defined for the eye. Jim's moon marks were very percise, regardless of the distance, obviously to the fact that old luna lacks an atmosphere, so that it's horizont always contrasts sharply against dark space. Maybe we'll get the same phenomenon.
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Tschachim
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« Reply #5 on: July 07, 2011, 10:53:48 AM »

Maybe the OVP people can find us away to superimpose images one day.

Yeah, there's nothing I can do there at the moment, the rendering "magic" used by CameraMFD or the Vostok add-on is beyond my skills (and perhaps won't help here anyway), sorry...

Cheers
Tschachim
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abr35
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« Reply #6 on: July 07, 2011, 10:55:10 AM »

OK, some of the vAGC articles are up, their very rough, but I won't have time to work on them for at least a few weeks. When I find the time, they'll have screenshots and diagrams, which will probably make up most of the tutorials.
Also, how do you initialize the W-matrix?
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meik84
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« Reply #7 on: July 07, 2011, 11:49:20 AM »

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Also, how do you initialize the W-matrix?
V67E
FL V06N99
XXXXX POS ERR - Position error in .01 nm.
XXXXX VEL ERR - Velocity error in .1 fps.
0000X OPTION CODE

The CMC has 3 w-matrixes: rendezvous (P20, option code 1), orbital (P22, option code 2), cislunar (P23, option code 3). All three are completely independent from each other and thus, can be initialised seperately by choosing the desired option code. Option code 0 will leave N99 without changing any w-matrix. The values of R1 and R2 N99 pops up with derive from the last used w-matrix, i.e. when P20 was the last before V67, its w-matrix data is displayed. R3 is 00000 initially -prevents you from killing a good w-matrix by accident. Wink

V25E to change data

PRO to reinitialize selected w-matrix with entered data; return to P00

Edit: as it comes along: Tschachim, could you set EMEM2002 and 2003 to 77776? According to the RDVZ doc, RMAX and VMAX were preloaded to -1 on Apollo7, so that every mark they took on the SVIB would led to FL V06N49. I don't know if 77776 is -1 in octal, but at least the display comes up on every mark I take. Wink
« Last Edit: July 07, 2011, 12:21:28 PM by meik84 » Logged
meik84
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« Reply #8 on: July 10, 2011, 08:10:34 AM »

...and I can confirm that star/earth landmark sighting with P23 works neatly (4 balls one and all balls), too. Happy Did you know that Apollo 8 used the westernmost end of Isla Tiburon as landmark? Cool
« Last Edit: July 10, 2011, 08:15:15 AM by meik84 » Logged
Tschachim
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« Reply #9 on: July 13, 2011, 06:27:56 AM »

Edit: as it comes along: Tschachim, could you set EMEM2002 and 2003 to 77776? According to the RDVZ doc, RMAX and VMAX were preloaded to -1 on Apollo7, so that every mark they took on the SVIB would led to FL V06N49. I don't know if 77776 is -1 in octal, but at least the display comes up on every mark I take. Wink

Done, but please note that 77776 is not -1, 37777 is -1. 77777 is "-0", 77776 is the smallest possible negative number, for example -0,00005 is 77776, so you might want to check if 37777 is working for that, too?

Cheers
Tschachim
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meik84
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« Reply #10 on: July 13, 2011, 10:12:52 AM »

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you might want to check if 37777 is working for that, too?
It doesn't. You'd better leave it at 77776.  Sundisk seems to have more differences than I thought...

Something more related to Apollo 8: Is there any way to choose the slot (CSM or LM) for the SV update in PAMFD? It was common that MSFN linked up a new SV in the LM slot and the astronauts would move it to the CSM slot by V47. Background is that during transearth coast Jim Lovell always worked with the SV he got from shortly after TEI for his P23s. MSFN linked up a new SV regularly, but Jim's SV was never touched and in the end Houston left the choice to the astronauts which one to use for the last MCC as they weren't able to tell which one was better.
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vrouleau
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« Reply #11 on: July 13, 2011, 10:33:10 AM »

The PAMFD only the main SV. Its doesn't have the code to update the 'Other Vehicule SV' location. That's other thing I wanted to wanted to add to test out the RR. The LM needs the PAMFD to upload both CSM SV and its own SV to orient the LM in rendez-vous procedure.

I've just added the MarkX MarkY MarkReject handling so be able to coarse align, then P52 the LM. Next was updating the both SV data on both vehicule.
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Tschachim
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« Reply #12 on: July 13, 2011, 10:59:42 AM »

It doesn't. You'd better leave it at 77776. 

Roger that...  Happy

Something more related to Apollo 8: Is there any way to choose the slot (CSM or LM) for the SV update in PAMFD?

Currently the slot is chosen automatically. If the source vessel in PAMFD is the vessel in focus, the CSM/1st slot is used, otherwise the LM/other slot is used, see ProjectApolloMFD::GetStateVector. vrouleau, you can change that if you like, of course.
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meik84
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« Reply #13 on: July 13, 2011, 11:12:28 AM »

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Its doesn't have the code to update the 'Other Vehicule SV' location.
Oh, it has. Just select anything different then the CSM with the SRC button and have a look at the data that is uplinked: buffer address 306 is 77776 or 77775, which tells the CMC that this update goes to the 'other vehicle' slot. The stupid thing is that you can't get the CSM SV in the 'other vehicle' slot: when you select the CSM as source, PAMFD will always update the 'this vehicle' slot. What we need is the free choice of the source vehicle, the receiving vehicle (CSM/LM) and the slot (this/other) the upload goes in.
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Tschachim
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« Reply #14 on: July 13, 2011, 11:14:49 AM »

What we need is the free choice of the source vehicle, the receiving vehicle (CSM/LM) and the slot (this/other) the upload goes in.
This is what I meant with my last post...  Happy

But you don't need a "receiving vehicle", this is the vehicle where you opened the MFD.
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