35 votes

Is it possible to see animals from space?

Yes, but it requires exceptional resolution. The GeoEye-1 satellite has 0.41 m resolution, and it has been used to count animals. Here you can see a picture it took of wildebeests: Image Credit: ITC ...
called2voyage's user avatar
  • 23.8k
30 votes
Accepted

Why not a "live" visual connection with Curiosity on Mars all the time?

Why not? Because we can't. We don't have full-time communication with Curiosity: Curiosity sends data to the Mars Reconnaisance Orbiter and Mars Odyssey. These are overhead twice a day at 12-hour ...
Hobbes's user avatar
  • 126k
25 votes
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Diffraction artifact on the March 16, 2022 JWST aligned test image

These star-like structures are caused by diffraction of light at any structure inside the optical path and are called diffraction spikes. In case of JWST it is caused by, as you say, the borders ...
asdfex's user avatar
  • 14.9k
23 votes
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Is it possible to see animals from space?

It is technically possible to see big animals, but we are still far from being able to identify them without context information. For commercial satellites, the highest spatial resolution is 31 cm at ...
radouxju's user avatar
  • 346
18 votes
Accepted

JWST - image acquisition - what is a dither pattern?

Generally, In astrophotography, to dither means to shift the pointing of the telescope slightly in random directions between exposures. This allows hot and cold pixels, cosmic ray artifacts, and ...
Camille Goudeseune's user avatar
16 votes

Diffraction artifact on the March 16, 2022 JWST aligned test image

This is just an addendum to @asdfex' excellent answer - and for my own curiosity. This shows the FFT of the aperture 'selfie' from NASA's website. The FFT does show the horizontal strip arising from ...
Roger Wood's user avatar
  • 3,844
14 votes
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How can stellar images be "subtracted" from a sequence of exposures? (difference imaging)

The principles of Difference Image Analysis (DIA) or Difference Imaging, which is very common in modern astronomy for finding new transient sources (e.g. asteroids, variable stars, including ...
astrosnapper's user avatar
  • 2,506
12 votes

Help me understand these tweeted images of JWST moving through Orion!

I've made the picture and I try to answer the questions or clarify : First picture (tweet) shows a cropped image of a usual stacked startrail image. So the first image is a simple overlay of all ...
Blixbuller at skysurfer77x's user avatar
10 votes
Accepted

Blue region in satellite image

According to this article, The red hot lava flowing from Mount Etna can be seen clearly in the image from Sentinel-2A. The surrounding snow has been processed in blue to distinguish from the ...
Hobbes's user avatar
  • 126k
8 votes

Is it possible to see animals from space?

- First count of individual birds from space - First complete count of an entire species population The 4-may-2017 BBC News item Albatrosses counted from space describes an effort to automate the ...
uhoh's user avatar
  • 149k
8 votes
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Spectral bands on an Earth-observing satellite

The 'bands' described here are regions of the electromagnetic spectrum. A band doesn't physically look like anything since it's just a range of wavelengths. However, different wavelengths are good for ...
Jack's user avatar
  • 9,976
8 votes

Which aspects of the JWST wavefront process are the most time-consuming?

You are missing several pieces of the puzzle. One piece is NASA's operational tendency to underpromise / overdeliver. (This apparently does not apply to the process of building spacecraft.) If it only ...
David Hammen's user avatar
  • 73.2k
7 votes
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How big would a QR code have to be on my roof for a satellite to be able to scan it given today's allowable resolution?

How big would a QR code have to be on my roof for a satellite to be able to scan it given today's allowable resolution? Say, using the Planet Labs satellites This is a supplementary answer. I've ...
uhoh's user avatar
  • 149k
7 votes
Accepted

What is synthetic tracking, and why would a 35 cm Earth imager be 10-30x better than Pan-STARRS or LSST for interstellar asteroid discovery?

The usual approach to tracking a dim, moving object is to move the camera to follow a predicted track while making a long exposure. Synthetic tracking starts with a series of sequential quick ...
Bob Jacobsen's user avatar
  • 12.6k
7 votes

What is the line in this picture?

The image was taked by the OCAMS instrument. OCAMS uses CCD (Charge Coupled Device) focal planes. The charges generated by the incident light in each frame are transferred down the columns one pixel ...
Vince 49's user avatar
  • 2,611
7 votes

What is the line in this picture?

The line you are referencing is because the Earth is very bright on a "black" background. It happens as the light overpowers the image chip, similar to the Starburst pattern bright headlights make on ...
Daryl Morning's user avatar
6 votes

Is it possible to see animals from space?

Whales seen from space, and not by the USS Enterprise. The BBC item Scientists count whales from space includes an audio interview with Hannah Cubaynes and says: The researchers, from the British ...
uhoh's user avatar
  • 149k
6 votes
Accepted

How to transform from the spacecraft coordinate system to image coordinates?

I wrote a paper on a similar problem, long time ago. I'll try to provide the gist of it. You need a model for the camera, so that you can map a point in 3D space to a point in the image. A simple ...
Ludo's user avatar
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6 votes
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Strange swirls on the latest image from SOHO

I'm not familiar with the astronomical considerations, but compare this to the same part of a newer image: This is almost certainly just text rendering gone wrong. Notice in particular that the ...
Kevin Reid's user avatar
5 votes
Accepted

How to develop a photographic film in lunar orbit?

It appears that the Eastman Kodak "Bimat" system used on the Lunar Orbiters was completely dry - in the sense that there were no free liquids. You can read about the process in detail at the Central ...
Organic Marble's user avatar
5 votes
Accepted

What image compression algorithm did the Voyagers use?

It would be nice to look at Voyager image data compression and block encoding by Urban, but it's paywalled. It's described in Space Data Compression Standards though, which says Robert Rice of the ...
Organic Marble's user avatar
5 votes

What is the line in this picture?

The streak is perfectly aligned to the vertical axis. Assuming that it hasn't been rotated, it is likely to be an artifact from imager chip, which may have saturated or overloaded - more charge/pixel ...
uhoh's user avatar
  • 149k
5 votes

Diffraction artifact on the March 16, 2022 JWST aligned test image

This is a great infographic that explains it: Source: https://webbtelescope.org/contents/media/images/01G529MX46J7AFK61GAMSHKSSN ILLUSTRATION: NASA, ESA, CSA, Leah Hustak (STScI), Joseph DePasquale (...
2080's user avatar
  • 171
4 votes

What is the line in this picture?

Largest original: https://www.asteroidmission.org/wp-content/uploads/2017/10/EGA_Plus_10_mapcam_Earth_Moon.png Blooming is vertical while streaking is horizontal: Some people use blooming and ...
Rob's user avatar
  • 3,256
4 votes
Accepted

Why meteorological images have missing lines in the center?

I found the answer. At least for Meteor-M. Missing lines in the center of image is a satellite defect. According to the link, this could happen every ~6mins due to internal buffer overflow.
dernasherbrezon's user avatar
4 votes

If all Starlink satellites had phone tier cameras & simple scopes, could images processed by their super-resolution imaging network be competitive?

So, restricting myself to space observations: No, for several reasons. I. From an astronomical standpoint, cellphone cameras are terrible imagers. By themselves, they have tiny apertures -- typically ...
Peter Erwin's user avatar
4 votes

How big would a QR code have to be on my roof for a satellite to be able to scan it given today's allowable resolution?

How big would a QR code have to be on my roof for a satellite to be able to scan it given today's allowable resolution? Say, using the Planet Labs satellites tl;dr: using 6x6 "augmented reality ...
uhoh's user avatar
  • 149k
4 votes
Accepted

How did the TIROS video tape recorders record and playback images rather than audio; how were the signals modulated?

According to your linked document the video signal from the vidicon (in record mode) The composite video resulting from vidicon readout is applied through the emitter follower to the modulator and ...
BobT's user avatar
  • 1,221
4 votes

JWST - image stabilization?

First let's see how Hubble did it for Hubble Ultra Deep Field (HUDF) The observations were done in two sessions, from September 23 to October 28, 2003, and December 4, 2003, to January 15, 2004. The ...
user3528438's user avatar
  • 1,641
3 votes

What image compression algorithm did the Voyagers use?

I tried to look for a publicly accessible link to the Urban (1987) paper that was referenced in @Organic Marble's answer. Fortunately, it is publicly accessible through the University of Arizona: ...
procyon's user avatar
  • 131

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