Path: ...!feeds.phibee-telecom.net!2.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: Jeff Liebermann <jeffl@cruzio.com>
Newsgroups: rec.bicycles.tech
Subject: Re: Biden Drops out on sure defeat.
Date: Mon, 22 Jul 2024 10:11:12 -0700
Lines: 43
Message-ID: <vk3t9jta4b2tgmthka61193fhvs25vqf7o@4ax.com>
References: <bWdnO.152274$z2Mf.12750@fx16.iad> <5q8r9jp7b2l3ggul998o0jo18got6ec9a0@4ax.com> <v7lj0p$kitk$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Trace: individual.net z2SBPrwcr02MzoA4ydY6YwTDV4w7SPRx0X4jBzLlmgrjG7XhvF
Cancel-Lock: sha1:7zlPRVGa4xbWmdLLQftp5QYdYYs= sha256:A806lsD1sUW5WtnBRZOBuK34PLAbJrkHtovBk7aZkUc=
User-Agent: ForteAgent/8.00.32.1272
Bytes: 2860

On Mon, 22 Jul 2024 08:23:53 -0400, Zen Cycle <funkmaster@hotmail.com>
wrote:

>On 7/21/2024 8:27 PM, Jeff Liebermann wrote:
>> On Sun, 21 Jul 2024 20:09:43 GMT, Tom Kunich <cyclintom@yahoo.com>
>> wrote:
>>> We need more people like him telling us that from 6 miles above the Earth that people throw visible shadow on all but two days a year.
>> 
>> 6 miles is 31,680 ft altitude.  That's rather low for earth
>> satellites.  The minimum orbital altitude is about 104 miles (167.4
>> km), where air resistance starts to become a problem.
>> <https://en.wikipedia.org/wiki/Low_Earth_orbit>
>
>Not to mention the fact that, yes, people throw visible shadows from 
>satellite imagery, and when outside of the tropics it happens year-round.
>
>Satellite image of a soccer field in San Francisco with players on the 
>field.
>https://maxarv2-cms-production.s3.amazonaws.com/uploads/image/image_value/125/02_soccer+fields+with+players_san+francisco_california_16july2024_wvl_half.jpeg
>
>This is free, higher resolution are available if you're willing to pay 
>for it, and the best resolution is not available to the general public.

Aerial photos and satellite images can be post-processed to remove
shadows using Photoshop or similar photo editing tools:

"Removing Shadows in Satellite Imagery with Photoshop"
<https://www.linkedin.com/pulse/removing-shadows-satellite-imagery-photoshop-ratan-ali-elooc/>

"Reducing shadow impacts in Aerial Photography"
<https://www.lynker-analytics.com/theblog/2021/3/24/reducing-shadows-in-aerial-photography>

However, removing shadows is not always beneficial.  The length of a
shadow can be used to estimate the height of a building.
"Shadow removal from historical aerial images"
<https://medium.com/forestree/shadow-removal-from-historical-aerial-images-ef212c43f38b>


-- 
Jeff Liebermann                 jeffl@cruzio.com
PO Box 272      http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann      AE6KS    831-336-2558