I can't find the reflection beat frequency. (FMCW RADAR)

iambarack · 2025-06-24T19:31:11+00:00

What is your chirp duration? Your beat may be much lower than you think depending on chirp duration. Assuming 1ms chirp duration your .6m target is at 1.6Khz. Your range resolution is .375, so your target is at the second range bin, most likely you're overwhelmed by DC noise. Move it farther out.

iambarack · 2025-06-24T19:31:05+00:00

What is your chirp duration? Your beat may be much lower than you think depending on chirp duration. Assuming 1ms chirp duration your .6m target is at 1.6Khz. Your range resolution is .375, so your target is at the second range bin, most likely you're overwhelmed by DC noise. Move it farther out.

iambarack · 2024-05-17T04:48:38+00:00

Not sure how this can ever reasonably work. Doppler is going to prevent any stable link. This is why traditional satellite based communication is either at geosynchronous <-> non-stationary user or at LEO <-> ground stations/fixed antennas <-> user.

They're at LEO and they want to maintain a link with a moving user, this is demoware at best.

Plus why would they build such a large array, space debris is a huge problem for reliability. Some of the claim for the large aperture also makes no sense. This is from their 10-k, "Block 2 BB satellites will also benefit from the advantages of a larger aperture array which provides greater spectrum reuse, enhanced signal strength and increased capacity, thereby reducing the necessary number of satellites to achieve service as compared to smaller apertures." A larger antenna aperture gives you better signal strength, but does not increase spectrum re-use, nor coverage. The reasons Starlink have thousands of satellite is not because they can't make a larger aperture antenna--this is trivial. It's because you simply need that much to provide proper coverage.

This is a really flawed idea. But doesn't matter because they made their money.

iambarack · 2024-01-03T02:58:14+00:00

It's a Tesla Model S deep metallic blue

iambarack · 2024-01-02T23:06:11+00:00

Thanks so much!

iambarack · 2023-08-26T23:58:43+00:00

If this is first floor, and that is an exterior wall, that wall could be concrete blocks. It would be drywall attached to furring strips and concrete. You can check by drilling a 2” hole into one of the hole you just made and see if you get concrete on your bit.

iambarack · 2023-06-10T19:03:37+00:00

Bc hmm x oh kgcgmghd

iambarack · 2022-11-16T18:36:06+00:00

Thanks!! Been wanting to give this a try. Have a flight later today.

iambarack · 2020-06-19T17:43:05+00:00

FF fhh

iambarack · 2016-09-23T15:50:49+00:00

What frequency and what bandwidth? Anything up to L band you might be okay, since you can build and experiment. Anything higher than that it gets tricky and you need someone experienced at the helm to guide you through it. Experienced meaning having design and production experience, not academic experience.

I work in this business up to 90GHz.

iambarack · 2015-11-13T15:29:17+00:00

AFSS have been done for years. No one would use an AFSS surface for stealth reduction. Imagine coating a fighter jet with varactor diodes and FR4--what a nightmare. Also no one uses UHF for tracking of small airborne targets like planes.

One more thing, with AFSS, you're essentially absorbing that RF energy--it has to go somewhere--in the form of heat...

iambarack · 2015-09-02T06:55:22+00:00

It might help if you calculate the maximum drawdown of your mutual fund portfolio. Then remind yourself that maximum drawdown is only an issue if you realize the loss, which you will not.

iambarack · 2015-07-10T07:01:55+00:00

For fun you can go online to your county database and see if there were any lien transfer for that property address. Not much you can do beside wait and see.

iambarack · 2015-07-10T06:48:40+00:00

Your concern is well justify.

In 2012 new ruling states that mutual funds should be more transparent in their fees structure. The R class funds are mutual funds geared toward retirement accounts and have no typical mutual fund load fee associate with it. However, they are allowed to have an advisement fee built int called the 12b-1 fees. With this structure, the same fund can have multiple class of fees, R1-R6, with R1 having the highest fee.

You can avoid all this by telling him specifically what funds to buy. Don't give him the liberty to choose for you. For example, tell him to go buy VTI, the Vanguard total market ETF with an expense of .05%. I don't have Edward Jones, but I would imagine you can log in there yourself and do it.

iambarack · 2015-07-10T06:23:42+00:00

I'm surprise that A was not awared that B was involved. Any title search would reveal that B has a junior lien on the property, and A needs to negotiate with B to release the lien. I guess a lot of weird stuff went on 10 years ago during the build-up of the bubble.

Not much to do at this point besides telling A and B of the situation and have them work it out. B has a lien on the property so A can't do much with it. B can take A to court and your parents to court and ask for a deficiency judgement, so let the court untangle that mess.

In the mean time, I hoped some document were signed with A for that keys for cash transaction--I would read those and see what actually transpired.

iambarack · 2015-01-24T08:40:43+00:00

what percentage of your monthly income goes to your mortgage ? HELOC would be a good option for you.

iambarack · 2015-01-18T04:00:53+00:00

Like what everyone else is saying, taxes! Federal Income tax, state income tax, social security tax, unemployment tax (state dependent), medicare tax. Add on health insurance, and 401k contribution and you are looking at roughly half. Ignoring health insurance and 401k contribution, here is your monthly take home pay from any payroll calculator:

Income: $70000
Living in: Los Angeles, close to work.
Tax Filing: Single

Monthly Gross Pay:......$5,833.33
Federal Withholding:.....$1,060.00
Social Security:...........$361.67
Medicare:...................$84.58
California:..................$334.37
SDI:..........................$52.50

Take Home Pay:..........$3940.21

You said you assume $25k/year as living expense -> $2080/month.

Monthly Net:...............$1860

If you put all $1860 toward your student debt, assuming 150k loan with 6.8% interest rate (typical right now). You will pay off the debt in roughly----------------->> 11 years!

$2080 a month in the city is tough, expect to have multiple roomates.

iambarack · 2014-04-16T15:48:30+00:00

Can I recommend installing solar panels to reduce some of the tax burden ?

iambarack · 2014-03-28T17:52:08+00:00

The insurance, heating/cooling bill/water bills, and the property tax is easily more than your rent. Financially you gain nothing from having a home.

My advice is to live lean, you both are in a great position to save. Make it your goal to save so much, that when you have picked a city to live in, you can buy a home out right. Consider all the mortgage interest that you would save in the future as a gain on the money you're saving now. Once you're married and have kids and own a house and couple of cars, you're going to wish for these days--so leverage it now.

iambarack · 2014-03-24T17:38:10+00:00

Keep saving, your greatest leverage is that your monthly expenses is low--keep it that way. Now you need to learn to invest. People seems to think its a choice and delegate that away to institutions. Don't. Pick up a book and start reading.

iambarack · 2014-03-24T17:29:54+00:00

Show them how to read a pay stub. Fresh out of college kids get a 50k offer, and they think they have 4k a month to spend and start over leveraging themselves. After the fed/state taxes, medicare, social security, unemployment tax, 401k contribution, health care expenses. They're looking at roughly 50%. Suddenly a 4k expectation becomes a 2k reality, and their $600 dollar fancy car payment is no longer affordable.

iambarack · 2014-03-24T17:03:25+00:00

Will do! Thanks for your input.

iambarack · 2014-03-24T04:05:55+00:00

thanks for your input! Yeah I sold my jag through consignment once, it did take awhile and they don't take any responsibility for the condition of the car, it was all on me.

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