Brutkey

Trammell Hudson
@th@social.v.st
Trammell Hudson
@th@social.v.st

The goal is to replace the six pages per latitude of the Pub 249 sight reduction tables with a single chart that can be printed two to a page.

Nautical almanac open to a page full of numbers with a printed circular chart in front of it and a circular slide rule as well.
Trammell Hudson
@th@social.v.st

Since the Zn result is symmetric around LHA and it is important to have a higher-accuracy on the Hc height, I've split the chart into two so they can be read separately

two circular charts, one with something that looks sort of like a globe and the other with a curving plot that relates the declination and local hour angle of a celestial body to its computed height
Trammell Hudson
@th@social.v.st

Friends don't let friends mix degrees and radians.

a chart that is completely covered in black lines since the diagrams are spinning around way too fast since degrees are so much larger than radians.
Trammell Hudson
@th@social.v.st

Expanding the declination range to +/-60 and the LHA to +/-180 makes the globe more obvious and shows the polar regions.

twelve circular plots that are beginning to approximate spheres with lines of latitude and meridians of longitude
Trammell Hudson
@th@social.v.st

That's better (and actually usable for measuring Hc and Zn for a given latitude, declination and LHA)

chart with a compass rose and lines indicating the height of a celestial body based on the other three parameters.
Trammell Hudson
@th@social.v.st

That's not right, but it's not wrong either...

plot of the azimuth angle for a given latitude and declination that has glitched out so it created mutiple overlapping spirals.
Trammell Hudson
@th@social.v.st

Making lazy coffee this morning

Hand coffee mill chucked to a Makita power drill. Various kitchen stuff is in the background.
Trammell Hudson
@th@social.v.st

How many is too many slides for my forty minute talk on celestial navigation for #39c3? Currently around fifty and still have a few diagrams to make.
(My usual pace is thirty seconds per image, so I think I still have room for more)

one of the slides with a sextant, almanac and math done in longhand
Trammell Hudson
@th@social.v.st

The server transfer from the train to the cargo bike was a success.

Yellow cargo bike with a server in a yellow bag.
Trammell Hudson
@th@social.v.st

Upgraded server on its way to the laundry room data center.

Yellow bag with a 2u server in it next to a train platform.