Hacker News: m2fkxy

New comment by m2fkxy in "NTSB Preliminary Report – UPS Boeing MD-11F Crash [pdf]"

m2fkxy — Fri, 21 Nov 2025 08:17:18 +0000

Mad dogs are MD-80s.

New comment by m2fkxy in "Mapping latitude and longitude to country, state, or city"

m2fkxy — Wed, 04 Jun 2025 10:00:16 +0000

That's true. I have a bias of having part of my formal education quite focused on geospatial topics. Seeing non-geospatial folks reinventing wheels taught in GIS 101 both makes me smile and grimace thinking that we have have been doing something wrong with basic tools and aspects of the trade not being wider known.

You can look into TopoJSON here: https://github.com/topojson/topojson And a good general introduction to topology in GIS setting is nicely found in QGIS documentation: https://docs.qgis.org/3.40/en/docs/gentle_gis_introduction/t...

New comment by m2fkxy in "Mapping latitude and longitude to country, state, or city"

m2fkxy — Wed, 04 Jun 2025 08:14:43 +0000

https://github.com/topojson/topojson

New comment by m2fkxy in "Mapping latitude and longitude to country, state, or city"

m2fkxy — Wed, 04 Jun 2025 08:09:53 +0000

> A side effect of the geometry simplication is that there are some very small gaps between states. Based on your use case, you'll need to handle the case of the point not being within any state borders. In these rare cases, you could fall back to a different method, such as distance checking centroid points, adding an episilon to all state borders, or simply asking the user. (The user may also be in another country or in the ocean...)

This is a common topic and easily dealt with by working with topology-informed geometries; most simplification algorithms support topology handling between different features. For instance, TopoJSON can be used.

New comment by m2fkxy in "The 'invisible crew' who have 35 seconds to prevent a Eurovision blunder"

m2fkxy — Thu, 15 May 2025 10:11:38 +0000

it depends on what flavour of English you speak. British English for instance tends to use plural for collective nouns.

New comment by m2fkxy in "Uber to introduce fixed-route shuttles in major US cities"

m2fkxy — Wed, 14 May 2025 19:42:47 +0000

This sounds like marshrutki. These are very common in post-Soviet countries to fill the demand left unmet by public transportation service.

New comment by m2fkxy in "Commercial jet collides with Black Hawk helicopter near Reagan airport"

m2fkxy — Thu, 30 Jan 2025 20:15:51 +0000

the TCAS data would have been displayed. but not on instruments or in any place that you typically pay attention to the most during final visual approach (ie., mostly outside).

New comment by m2fkxy in "Commercial jet collides with Black Hawk helicopter near Reagan airport"

m2fkxy — Thu, 30 Jan 2025 11:16:14 +0000

TCAS RAs are inhibited at low altitude.

New comment by m2fkxy in "Celestial Navigation for Drones"

m2fkxy — Tue, 21 Jan 2025 07:47:38 +0000

yeah, and then you need to get refreshed orbital elements for those satellites. not good if you are in an airtight environment.

celestial ephemerides don't change nearly as much.

New comment by m2fkxy in "An Update on Apple M1/M2 GPU Drivers"

m2fkxy — Fri, 01 Nov 2024 09:24:30 +0000

your point being?

New comment by m2fkxy in "'Visual clutter' alters information flow in the brain"

m2fkxy — Mon, 28 Oct 2024 10:34:09 +0000

...which is obviously designed to be maximally visible from the public space.

New comment by m2fkxy in "Show HN: I built the most over-engineered Deal With It emoji generator"

m2fkxy — Tue, 15 Oct 2024 14:00:59 +0000

it's useless thence I love it.

I lied, in fact I just used it to create a couple Slack emojis.

New comment by m2fkxy in "In a rare disclosure, The Pentagon provides an update on the X-37B spaceplane"

m2fkxy — Mon, 14 Oct 2024 14:44:34 +0000

> Plausibly, there is no real monitoring of co-orbiting bodies in space

[capable] nations operating sensitive satellites and other space assets absolutely are monitoring foreign objects maneuvering in their orbital vicinity.

New comment by m2fkxy in "Satellites Spotting Aircraft"

m2fkxy — Wed, 11 Sep 2024 19:50:26 +0000

not at all, I love it too

New comment by m2fkxy in "How economical is your local Taco Bell?"

m2fkxy — Wed, 11 Sep 2024 12:38:06 +0000

it's also not the proper scale type for sequential data (red/green is diverging, but there is no central value defined in the linked map).

New comment by m2fkxy in "Satellites Spotting Aircraft"

m2fkxy — Wed, 11 Sep 2024 09:07:32 +0000

  For those less obsessed with SAR images

Touché!

Also good point regarding multibounces and multipath. I would expect eg. landing gear returns to be standing out in those cases (cockpit too, although probably the canopy is coated to prevent radar penetrating).

New comment by m2fkxy in "Satellites Spotting Aircraft"

m2fkxy — Wed, 11 Sep 2024 08:50:38 +0000

Yes, radar shadow is how you would find it. But your sensor must be performing well enough for it to be able to distinguish a shadow from the surface backscatter (ie. radar signature) the aircraft is sitting on. This is usually not a problem for rough surfaces (eg. grass or dirt, or some types of pavement), but it can be more problematic for surfaces with more specular scattering.

New comment by m2fkxy in "Satellites Spotting Aircraft"

m2fkxy — Tue, 10 Sep 2024 20:09:46 +0000

A little nitpick about:

  The number of looks correlates with a higher resolution.

Yes and no. When you task an image, you usually (as is the case with Umbra) specify your desired ground resolution, eg. 25, 50, 100 cm, etc. There are two dimensions in a SAR image: range and azimuth. Range resolution is determined by the SAR system bandwidth. Azimuth resolution is determined by the integration angle (the angle formed between your target and your satellite from start to end of the collection).

Let's assume you want a 50 cm image. Your range resolution will be equal to that and, in a 1-look image, your native azimuth resolution will also be 50 cm. What happens when you request a multi-looked image, is that the satellite will collect data over your target for a longer amount of time (and thus over a greater angle diversity). Range resolution will not change; however, in the natural ("native") image, you get asymmetrical pixels: taking the same target resolution of 50 cm, a 2-looks image will have a 25 cm azimuth resolution. For 3-looks, ~16 cm. And so on.

What then happens during the processing of derived products (eg. GEC) is that the pixels are squared: to do that, you have to average out the pixels in the azimuth dimension. This greatly improves what is called the radiometric resolution (ie. how much information a pixel contains), by cancelling out the speckle and averaging the noise. But for all intents and purposes, on a multi-looked image (which is what the GEC products that you use are), spatial resolution remains the same, square pixel.

[SAR nerds here: I am not mentioning the slant-range-to-ground-range process, and I am also ignoring the resolution vs. sampling distinction for simplicity]

New comment by m2fkxy in "Satellites Spotting Aircraft"

m2fkxy — Tue, 10 Sep 2024 19:52:28 +0000

yes, received power is inversely proportional to the distance squared. it's hard to overstate how ridiculously small the amounts of power are at play with spaceborne SAR systems.

New comment by m2fkxy in "The U.S. Navy's $100M checkbox (2019)"

m2fkxy — Fri, 23 Aug 2024 13:12:42 +0000

most complex and/or commercial aircraft do share the workload between a pilot-flying, and a pilot-non-flying—in addition to the captain & FO hierarchy you are probably aware of.