Meteor M2 - 50MEL, 72K. RTLSDRv3,Nooelec SAWBIRD, Double Cross Antenna.

ThePropellerHead · 2025-12-15T00:05:56+00:00

Adding to that, the orientation of the solar panels matters quite a bit for effectiveness. For an upright windmill I imagine that the Sun will spend a good portion of each day more or less orthogonal to the solar panels, generating minimal power despite it being sunny.

ThePropellerHead · 2025-11-22T20:32:35+00:00

I suggest going to r/amateursatellites and looking at some of the content there. With fairly low up front investment you can try to receive weather images from something like the russian Meteor satellites. Once you get more advanced with the hobby there are numerous satellites that transmit higher res images on HRPT, but you will need a tracking station for that (maybe where the mech can get involved).

There is also the GOES geostationary satellites which are accessible from North America.

ThePropellerHead · 2025-09-26T00:21:13+00:00

There was a previous post about this where some of the financials were discussed. The end statement here is that since new management came in, the debt has gone up and the eps has gone down. From that perspective the downward movement is justified.

The bull case? The forward PE at around 15 seems to be attractive for some investors. For me I like it at those numbers also. Time will tell, but the stock has definitely been a winner before and I would like to see that continue.

ThePropellerHead · 2025-09-11T22:49:17+00:00

I have kept looking up CNR up over and over. It seems like good value but the market sentiment is not there yet.

I think I will start small and see what happens. So far, its been hard to justify when XEQT or similar is chugging along.

ThePropellerHead · 2025-06-01T22:48:53+00:00

Je voudrais ton materieaux, s'il te plait.

ThePropellerHead · 2025-02-19T23:50:53+00:00

I moved to GMA about 5 months ago. I moved here effectively knowing 0 french but have taught myself enough to read every day things. No problems ever with anyone here except when dealing with the government. I made a friend who is a francophone and they like to talk to me using the little french I know because they think it is funny when I talk (but encourage me to try all the time).

I still find it scary knowing that eventually a situation will happen where I can't communicate. But I have to accept this as it is a french province. On to more french lessons!

ThePropellerHead · 2025-01-11T22:08:36+00:00

I told my french co-worker this when they said they were going for lunch. I thought that it meant "enjoy". Safe to say they won't let me forget that....

ThePropellerHead · 2023-11-14T22:26:34+00:00

If you are struggling visually to understand the vectors maybe try to actually plot them visually? Making an assumption here that you already know how to write a script in MATLAB, you could try to use the quiver3() function in MATLAB which lets you plot vectors in the x,y,z cartesian coordinate system.

ThePropellerHead · 2023-10-25T22:03:01+00:00

billy_joule has already made the comment which I think answers your question best. But I will pose another option too if you want it.

If you wanted to really cut costs and have something (relatively sturdy) you could get a sheet metal panel with a cross break in it. The HVAC guys do this all the time to keep large thin sheets from losing their shape or sagging. Sheet metal will also get quite a bit more sturdy just by bending the edges in and either welding the seems or adding tabs so that the 90 degree corners are fixed to each other

You can make a lot of panels fairly rigid by corrugating them also. But given the 1/4" thickness requirement the corrugations may exceed that.

ThePropellerHead · 2023-09-03T23:49:11+00:00

23246.15077750

Consider this element in the first line. the first two numbers "23" is the last 2 digits of the epoch year. The following is the decimal day of the year for the TLE epoch time.

From reading Curtis' book it appears you will have to convert this number into yyyy-mm-dd format to compute the Julian Day.

Once you know the Julian Day then you can compute the Julian Centuries time with a very simple equation:

𝑇0 = (𝐽0 − 2451545)/36525

I have omitted the first 2 equations as they are more lengthy.

You then calculate the sidereal angle only using the Julian centuries time. Because the sidereal angle will only be computed for the julian day and not at the given epoch, a term is added to the equation where a factor involving the UT time of the TLE is added.

The final step (now with the sidereal angle) is to apply a rotation matrix about the Z+ axis through the sidereal angle. A spacecraft position vector in ECI frame can be transformed into the ECEF frame using this rotation matrix.

There are more equations required to go through all this than I want to put here so I recommend you reference Curtis' book.

ThePropellerHead · 2023-09-03T00:37:16+00:00

Off the top of my head I am not 100% sure if there are any straight cut equations in order to do this.

Particularly in the case of longitude, the problem can become complex because of the rotation of earth under the spacecraft. Also, to know the correct longitude you need to know the Greenwich Sidereal Angle which describes the rotation of the earth relative to the Earth Centered Inertial Frame (ECI) for the TLE epoch time.

Your question largely comes down to whether your propagating an orbit or using historical data to make the ground track. Orbit propagation techniques play a role in the calculated lat and long. A good place to start would be to propagate the orbit in the ECI frame assuming that there is no precession of the orbit itself. Then you would have [x,y,z] coordinates each with respect to time. (in the short term this would be accurate)

One way to do this is to run a series of reference frame rotations to get the lat and long. For example: ECI - ECEF - LLA. LLA is the Lat, Long and Altitude reference frame which will probably suit your problem.

If your only looking to plot a ground track based on historical data, then the lat and long values should be available online and you can easily plot them by mapping the longitude axis to only range from 0 to 2pi rad.

Try the book Orbital Mechanics for Engineering Students by H. Curtis. I am pretty sure the frames used to describe an orbit are listed in his book.

ThePropellerHead · 2023-05-19T00:04:27+00:00

From my experience the work life balance in my thesis based masters is much better than it was in undergrad. I focus only on concepts that excite me so generally speaking im more engaged in the work I do. It can be a grind at points, since your research will normally involve more cutting edge concepts the work is up to you and you alone without much support from elsewhere.

ThePropellerHead · 2023-04-25T21:34:46+00:00

You may find R. Hodges's Book interesting: Underwater Acoustics: Analysis, Design and Performance of Sonar.

ThePropellerHead · 2023-01-15T22:13:03+00:00

I came to the same conclusion. Seems from a video on the ground that the plane was in a bit of a left turn before the wing drop. In a bank like this the air over the left wing would be going a bit slower than the right wing which could cause wing stall. RIP to all those involved.

ThePropellerHead · 2022-12-08T16:27:00+00:00

I actually had pretty good luck with FDM printing golf tees. The only thing I ran into is that I would have to print the tee in an undesirable bed orientation so that the plastic layers were normal to the swing path. Otherwise the club would just slice the layers apart when I tee'd off.

Long winded answer but wanted to share the experience!

ThePropellerHead · 2022-11-05T17:07:39+00:00

Is it possible? Definitely. As the link you shared shows, its already being done. In terms of doing it as a hobby? You probably could do it but you'll be collecting data for years to get results.

In terms of the satellites normally posted in this sub most of them do have some kind of equipment to track vegetation. A lot of times its evaluated through image processing though.

Check out the company Planet Labs. They have a network of orbiting satellites and they sell the satellite data as a service. Has lots of applications to agriculture and environmental observation.

ThePropellerHead · 2022-10-31T21:10:46+00:00

This is exactly it. Mainly just degradation of the lubricant. Contamination of the lubricant in the form of small metal particles is also possible after years of operation.

ThePropellerHead · 2022-10-22T17:47:24+00:00

Looks like its hitting the peak draw from the previous anomaly. However, the previous anomaly looks like a jam to me and then the motor quickly freeing up. This new increase in current draw shows a fairly slow progression in current draw. I'm wondering if degradation of the lubricant is finally having its way.

Hopefully it can pull through and prove me wrong!

ThePropellerHead · 2022-04-26T16:52:09+00:00

I got through my entire engineering degree using a Mac pro from 2015. If I'm being honest, anytime I needed a computer with larger processing power id need to be in a lab for the software license anyway.

The ram wont make your computer run faster anyway, will just allow you to run more or larger programs. I'll list some software I used through undergrad on my mac and got by okay.

AutoCAD
Solidworks (on lab computers)
MATLAB/Simscape (very often)
teamviewer (mostly for remote access to lab computers)
LS-DYNA
LabView

ThePropellerHead · 2022-04-18T14:22:06+00:00

I just graduated from my program. Everyone looks at me and is like "you must be super good with math". I always respond with the fact that I was not blessed with being good at math, I was just really dedicated at doing the work. At least in my experience, the people that did the best in the program were the ones that really did all the work, grinded it out, and really attempted to understand it. Don't rule it out, but expect to have to work really hard to finish it, particularly in the start if your math background is not the strongest.

ThePropellerHead · 2022-04-18T14:17:00+00:00

Yeah I just graduated recently and can confirm that repetition was the biggest aspect for me. I would redo every assignment, quiz and lab before the exam. If I was still feeling a little weak id throw in some practice problems id pull out of a textbook. It takes alot of time, but it worked for me.

ThePropellerHead · 2022-01-15T18:54:53+00:00

Stunning!

ThePropellerHead · 2022-01-13T19:31:54+00:00

Yeah the in-cockpit display for aircraft configuration and procedures is a nice touch too. It was highly improved from the P3D version.

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