Sweet, just brought back up my APRS radio station transmitting on both VHF and HF frequencies. Looks like it is working great I am being heard in both Ireland and Canada on the HF side!
Can't wait to get back to coding PEAK (the APRS software I run that runs a next gen version of APRS I am developing).
Just a reminder, historic climate change predictions modeling human caused global warming has turned out to be surprisingly accurate.
The attached image shows the average of the leading predictions from 2004 and how it tracks to the actual observed climate change. The accuracy turned out to be quite exceptional.
I have seen this claimed on reddit and imagur to be an actual composite image of a cell from "radiography, nuclear magnetic resonance and cryoelectron microscopy". Yet despite seeing it posted all over the inernet claiming its a real image I can not find a single scientific source for it. Anyone who can figure out if this is legit or not please comment.
In case you are unfamiliar Jupyter Labs is a way to write notebooks (formated text with inline code that runs and displays elements like graphs or text). These notebooks are often used in science settings and as such I have integrated all the science tools python has to offer more or less. It is a great place to write up technical documents with working code side by side with the data it produces, but its also a great environment to play around with various programming languages and try out snippets without needing a full project environment. Thanks to the support of many different languages it is a great way to learn and try a language without needing to set anything up, since it all runs from a container.
In short just run a single command to bring up the container (the image is pulled from docker hub) and in a few minutes you will have a running web server you can point your browser to and start coing in any of the 7 languages supported. I use it to share snippet ideas. It is backed by anaconda so you can easily upload a notebook to their servers and then share a static version of it with people by sharing a link to the notebook, which can be viewed directly without needing any apps, not even Jupyter Labs installed.
Check it out here:
or just get the docker container image directly: modjular/jupyter-all:latest
Interesting fact of the day: The speed of light has only been proven to be a constant speed round trip. Not the instantaneous speed of light nor the speed of light while heading in a single direction has ever been able to be proven as constant.
In other words, it has never been experimentally disproved that light doesn’t, for example, preferentially travel at half the speed of light in one orientation, but instantaneous in another. In fact it may very well be impossible to test the one-way speed of light due to the very consequences of relativity itself.
This is so cool. With just a little bit of modification using a single 3d printed part glued to the side of the head of a 3d printer this japanese team managed to create a fully autonomous robot that can basically built its own tools, pick them up, and then use them to manipulate its environment.
I was asked to explain the space-weather ticker I posted earlier (attached). This was my reply.
First off the are two categories of radio operation that is relevant and effected in opposite ways..
space to earth
Number 2 breaks down in two ways as well that is
2a. line of sight operation, vs
2b. skywave operation.
Skywave operation is really the most relevant here, line of sight might be effected somewhat by noise floor effects from sun but that is only relevant some of the time.
There are two main factors from the sun that affect operation. One is radio interference, this would be caused by flares and ejections directed at earth. In extreme cases it can cause an EMP but thats very rare.
The other is ionizing radiation in the form of UV (a much shorter wavelength version of UV than what reaches the earth), ionized particles, solar wind and similar. This ionizes the ionosphere in a specific way that causes radio waves to be blocked and/or reflected. Basically there are two regions in the ionosphere both in whats called the F-region.. These are F1 which is at 200 km above sea level, and F2 which is at 300 km. The higher F2 layer allows for radio signals at a particular angle to be reflected, this allows radio operators to bounce their signals off this part of the sky and reach distant receivers. Since F2 is much closer to the ground this particular region actually blocks long range communication and thus significantly reduces the distance a radio signal can reach to mostly line of sight.
Usually, when the radiation is high enough, we see the F2 layer ionize first in the morning (basically when the sun is just coming up for people who live near your horizon), which makes the morning the best time to transmit. By afternoon the F1 layer is ionized by sun radiation and thus the signal is blocked again.. the reverse happens in the evening. So early and late day propagation is best. This is called gray-line propagation.
There is also E layer propagation which operates at much lower frequencies and at steeper angles. This is what is used for very short distance transmissions within the 100’s of km. This is called NVIS (Near Vertical Incidents Skywave).
Reading the screencap
Now with this said, it only works when the radiation from the sun is just right. Basically there needs to be enough radiation from the sun to actually fully ionize the layers.
SFI on the chart stands for “solar flux index” this is a measure of the quantity of ionized particles and solar wind measured. This is usually in the range of 0 - 400 with 0 - 100 being poor for propagation, 0 - 200 being marginal, and 200+ being ideal/good.
SN stands for sunspot numbers, these effect different layers selectively. sunspots reflect the intensity of the sun’s magnetic field. It ranges from about 0 to 400 as well.
Lower values here show a preference to ionize lower levels of our ionosphere. 0 to about 150 will preferentially ionize the E-region and be ideal for low frequency propagation (160m wavelength to 80M) in the NVIS configuration, so very short distance (100’s of km) propagation only which is all these low frequencies can ever do.
Higher values, above 200 means the F-regions are preferentially ionized. That means low frequencies like 160m and 80m will not propagate at all and only work line of sight (10’s of km), but higher frequencies ~20m and higher in frequency will propagate via skywave. These frequencies now can propagate 1000’s of km around the world in these conditions (assuming SFI and other factors are good).
The next line is K-index just labeled K. This one is rather complicated.. it basically looks at the horizontal component of the earth’s magnetic field and how it is disturbed (which is an indirect way of measuring the solar winds and its interaction of the earth).
This doesn’t effect the ionosphere itself so much as the other measures since its only partly effected by solar winds. This is used as a measure of expected band noise and thus how high the noise floor will be. the max value is 9 and indicates significant noise. 5 is about the cutoff where geomagnetic storms are present.
The K-index is not linear and is calculated from the a-index (lowercase a, different from A-index below).
is really just another way of measuring K-index. Or to be more precise both A-index and K-index are calculated from the underlying a-index (a-index is different from A-index). The A-index is the average of the last 8 a-index, and thus has a much simpler interpretation.
Think of A-index as a long-term rolling average of the K-index in a different scale.
Generally A-index is even less linear than K-index with 0-50 being low noise and 100 - 400 being high noise.. lower is better.
304A stands for “304 Angstroms” which is the wavelength of UV light measures. Basically its the strength of UV radiation from the sun as measured from space (different than earth UV levels). the “@ SEM” part refers to the instrument on the satellite used to record it, called SEM, SOHO and EVE are other possible instruments used to get this measurement and it changes depending on the instrument available at the time.
In this case higher is better as it means more of that F-layer ionization I mentioned.below 80 is poor, 150 and up is good, 250 and up is amazing.
This is Proton and Electron flux. These have a similar effect as UV except they ionize the E-layer more so than the F-layer. So they harm long distance short wavelength propagation but improve short distance long wave-length propagation.
This is just the predicted chance of aurora. Not directly relevant for radio.
This tells us the largest lattitude likely to see the aurora.
Bz and SW
This is the interplanetary (in space) magnetic field vector (B-field means magnetic field). This is the magnetic field that is incoming and striking the earth from space.
The Bz part is the intensity, the SW part is the direction in degrees. When it lines up with the earths magnetic field it strengthens it, when it doesnt it weakens it. Positive values strengthen it, negative weaken it.
Everything else is self explanatory I suspect. “solar flare prob” is the percentage change of a solar flare, which we dont tend to know until just a few minutes before their ejections strike.
“MUF” stands for “Maximum Usable Frequency”. It indicates the highest frequency (shortest wavelength) that is likely to be capable of bouncing off the ionosphere (f-layer or e-layer) and therefore the highest frequency capable of skywave propagation.
Hey everyone, a supernova just went off in Cassiopeia!!!! Right now it is in the early stage so only visible by telescope but after a few days it is likely to be visible to the naked eye. Supernovas are fairly rare so might want to make some time to see this one!
All science, all the time.
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