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» Online Classroom   »   » Public Discussion of Cel Nav   » Starpilot 89 Strange LHAA Sunrise/Set

   
Author Topic: Starpilot 89 Strange LHAA Sunrise/Set
Herman


 - posted January 01, 2017 07:07 AM      Profile for Herman           Edit/Delete Post 
Today 1-1-2017 DR 51degr 18min N, 08degr 32 min E
ZD -1, Well first Happy Newyear and clear skys.
Run Sunrise/LAN/Sunset [2][1] input Today + DR
Last Screen is LHAA AM twilight. The Manual gives LHAAries at the midpoint between nautical and civil twilights. The gives times are correct between, but the corresponding LHAA are not?? If I use the AM time off GMT+1 07:27:53 and use this time corrected to UT 06:27:53 as input off the LTA Aries Pub 249 V1 I get 198degr 04min, the programs gives 206degr 36.4min thats much higher, the same output at LHAA PM, also about 8degr 30min higher?? This LHAA has to be used for Setting the 2102-D starfinder but It seems me it is set to late. I cannot understand how the LHAA is calculated by the program, from which time??
Again a bug in the program??
HermanD

From: Holland
Capt Steve Miller


 - posted January 02, 2017 11:08 AM      Profile for Capt Steve Miller           Edit/Delete Post 
I have looked at your data.
The 198° 04.4' (I got this from the Nautical Almanac and agree with you re the GHA Aries) that you mention is the GHA Aries and when you add your Assumed Longitude of 8° 32' to compute LHA Aries - the LHA Aries is 206° 36.4' which is the value that the SP89 gives.
It looks like the computation you did 'off the LTA Aries Pub 249 V1' gave you the GHA Aries NOT the LHA Aries.

From: Starpath
Herman


 - posted January 02, 2017 11:45 AM      Profile for Herman           Edit/Delete Post 
Hello Steve.

I see the TI-89 ad the lon of the DR to the GHAA directly.
Now I understand how that is calculated.
The only thing I mis in the TI-89 is calculating off GHAA for a given time. That can be used for workout textbook examples.
Could be for instance Star no:0= Aries.
Thats not much coding I suppose, could be done directly by solving the sight-analyser ZD bug.
Thanks for the Info.
HermanD

From: Holland


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