02-10-2021, 04:58 AM
I was debating whether to call this post ah ha moment or IM SO STUPID.
Its been raining for days around here so when the clouds took a break yesterday I quickly grabbed the sextant, a plate of vegetable oil, a watch, paper and pencil, and hit the back yard.
It only took a moment to set up and I didnt have much time; the clouds were closing in again and already dimming the sun. it was necessary to reduce the sextant shades.
I took the shot between ripples in the reflection and was satisfied I got a reasonable single shot. I immediately recorded HS and time and went inside.
I then turned on my short wave radio and dialed in WWV. My watch proved 2 seconds fast. No problem, I added the notation to the sight record. I put everything aside and finished my laundry.
Later I put the sun shot to work. I gathered my reduction stuff and sat down to work the problem.
I use a small plasticized card I developed which very briefly outlines the reduction steps. I dont use a proforma perse, but apply the reductiom math to any old scratch paper or notebook. I save tons of paper that way. My reductions use as little as half a page in a pocket size notebook.
So off I went on my merry way doing the reduction then plotting Zn and the intercept... Hmmmmm
Something wasnt right.
I've done this a hundred times, but my lop was short about 8 miles. I began to doubt my shot and went over it in my head. I redid the math, rechecked gmt, dec, d correction, hc, everything. I took the reduction to the dinner table - I still couldnt figure it out. I put the reduction away and turned on the big screen.
I started watching the movie CONVOY, that great old trucking classic, which moved me into a sense of persistance. I hit the pause button and started reworking the reduction. - then it hit me... I'm sooooo stupid.
So here is the confession - there are two ways to get the first difference for Hc. You can do the math, dec increments/ 60 X d correction factor, or use table 5. So I mistakenly did two thing wrong complicating the error. I divided 60 by the increments, then I multiplied by table 5 result. I slapped myself in the head - hard. 24 hours later I'm still asking myself why I did that.
It literally took hours to find the error and correctly reduce the shot, but the result was absolutely satisfying. The lop was almost spot on which boosted my confidence in taking sun shots.
I have the script writer of CONVOY to thank for instilling in me the desire to persevere. I conquered my own ignorance and lived to tell about it.
Cheers
Its been raining for days around here so when the clouds took a break yesterday I quickly grabbed the sextant, a plate of vegetable oil, a watch, paper and pencil, and hit the back yard.
It only took a moment to set up and I didnt have much time; the clouds were closing in again and already dimming the sun. it was necessary to reduce the sextant shades.
I took the shot between ripples in the reflection and was satisfied I got a reasonable single shot. I immediately recorded HS and time and went inside.
I then turned on my short wave radio and dialed in WWV. My watch proved 2 seconds fast. No problem, I added the notation to the sight record. I put everything aside and finished my laundry.
Later I put the sun shot to work. I gathered my reduction stuff and sat down to work the problem.
I use a small plasticized card I developed which very briefly outlines the reduction steps. I dont use a proforma perse, but apply the reductiom math to any old scratch paper or notebook. I save tons of paper that way. My reductions use as little as half a page in a pocket size notebook.
So off I went on my merry way doing the reduction then plotting Zn and the intercept... Hmmmmm
Something wasnt right.
I've done this a hundred times, but my lop was short about 8 miles. I began to doubt my shot and went over it in my head. I redid the math, rechecked gmt, dec, d correction, hc, everything. I took the reduction to the dinner table - I still couldnt figure it out. I put the reduction away and turned on the big screen.
I started watching the movie CONVOY, that great old trucking classic, which moved me into a sense of persistance. I hit the pause button and started reworking the reduction. - then it hit me... I'm sooooo stupid.
So here is the confession - there are two ways to get the first difference for Hc. You can do the math, dec increments/ 60 X d correction factor, or use table 5. So I mistakenly did two thing wrong complicating the error. I divided 60 by the increments, then I multiplied by table 5 result. I slapped myself in the head - hard. 24 hours later I'm still asking myself why I did that.
It literally took hours to find the error and correctly reduce the shot, but the result was absolutely satisfying. The lop was almost spot on which boosted my confidence in taking sun shots.
I have the script writer of CONVOY to thank for instilling in me the desire to persevere. I conquered my own ignorance and lived to tell about it.
Cheers