What's happening!

Have you eaten?

I like how different cultures greet each other.

I’ve been working on my Gravity project. The goal is to use GNSS satellites as a gravity telescope which can resolve the direction of the Sun as seen by gravity. Why? For fun. Which it has been. I located the data for GNSS satellites (all of them, though I will just be using GPS, GloNaSS, and Galileo) which after post processing to integrate all the observations from ground truth gives me 80 satellites accurate to about 3cm. The signal I need is probably around 2 meters of drift over 10 days so with 80 sats and about 2,880 measurements each there should be enough accuracy.

equatorial Celestial Reference Frame

The calculations are affected by the Sun and Moon, of course. And general relativity. And the oblateness of the Earth. And Jupiter, Saturn, Venus, Mars, Uranus, Mercury, and Neptune. In roughly that order. Ceres seems well below threshold. Fortunately (by design) the GNSS fleet is well above the effects of atmosphere. I do wonder about drag from the Earth’s magnetic field, but have not yet located any discussion of that.

Accelerations down to about 10 picometers/sec^2 will be relevant. I will need double-double precision in the calculations - fortunately the Julia language has a nice package for that. I should have this done in the coming week, which will be summarized here in Poratbo blog though the main report will be on arXiv and the code and sample data will be on GitHub.

Meanwhile, I’ve had an idea for a different SRAM layout buzzing around my head and when Fred Chen pointed to a publication estimating layout parameters for a 3nm process using ribbon-FETs it all clicked into place. I’ve finished the 3D model and it is quite pretty, as well as a lot more compact than my Mock4 design. This will be published on Monday morning (a week later for free access).

Have a good weekend, folks!