Questions tagged [earth-observation]

questions about the observation of the planet Earth from space, usually for scientific, technical, or other well-defined reasons, or about the spacecraft that do this. This tag is usually used for systematic observations, but it could also apply to a questions on specific images or photos observing something unusual requiring analysis.

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Sentinel-2C and frequency of acquisition

Sentinel-2C, the third Sentinel-2 satellite of the Copernicus program, is planned to be launched in 2024. Currently, the Copernicus SENTINEL-2 mission "comprises a constellation of two polar-...
AlixL's user avatar
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5 votes
1 answer
151 views

Time of satellite passing overhead

Curious lay person here... I download and analyze Sentinel-2 imagery for a variety of mapping tasks. According to the Sentinel mission description webpage: The Sentinel-2 mission orbit is sun-...
Stu Smith's user avatar
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0 votes
0 answers
39 views

Can the JWST look at Earth? What would it see? [duplicate]

There's a few questions on the site about whether we can see the James Webb Space Telescope from Earth (i.e. here and here), but I'm wondering about the opposite - can we see Earth using the JWST? I ...
Dubukay's user avatar
  • 101
4 votes
0 answers
85 views

Study "earthquake" lights from satellite videos

A recent youtube video, "Unexplained Earthquake Light Phenomenon Finally Captured on Camera", by Anton Petrov (who I have a lot of respect for as a science reporter) shows numerous videos of ...
tckosvic's user avatar
  • 2,262
5 votes
3 answers
344 views

Is there a database of recent satellite images which will allow me to estimate how much of Mariopol has been destroyed?

In the news I often see satellite images from Maxar Technologies showing a neighborhood or sector of Mariupol to have been destroyed in shelling. However, I would like a more comprehensive view of the ...
Tom's user avatar
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1 vote
0 answers
58 views

Will Cygnus do anything special when it "looses its NACHOS"?

CBS News' NASA's new "NACHOS" instrument could help predict volcanic eruptions explains that this nanosatellite will be deployed from the Cygnus spacecraft launched February 19, 2022 after ...
uhoh's user avatar
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3 votes
2 answers
593 views

Satellite Revisit Time Analysis

I am currently making up my mind about revisit analysis. I am searching for clever algorithms to implement this in Matlab. I want to define targets on Earth surface and get the revisit times for each ...
af_ab's user avatar
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1 vote
0 answers
45 views

How does "onboard GPS" suggest "escalation speed and severity of a storm caused atmospheric drag to increase up to 50 percent"?

Engadget's says: A recent batch of SpaceX’s Starlink internet-beaming cubesats met with tragedy on February 3rd when a 49-member cohort of the newly-launched satellites encountered a strong ...
uhoh's user avatar
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6 votes
1 answer
449 views

Why didn't SpaceX see that geomagnetic storm coming? Was this a fluke or could this happen more frequently in the future? (R.I.P. 40 lost starlinks)

Ars Technica's SpaceX loses up to 40 satellites to geomagnetic storm after Starlink launch explains that a geomagnetic storm heated Earth's upper atmosphere (circa 200 km) so much that the aerodynamic ...
uhoh's user avatar
  • 149k
0 votes
1 answer
102 views

Why does Q-SAT look like a buckyball?

Tech.China.Com.cn's August 7, 2020 article Tsinghua University Successfully Launched Gravity and Atmospheric Science Satellite (Chinese, title translated to English) includes the image above of what I ...
uhoh's user avatar
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1 vote
1 answer
172 views

What are all these packages attached to a side module of the ISS? How did they all get there?

Ars Technica's New images of the International Space Station reveal that it is still a jewel includes the photo below and I've added a view of a side module with a collection of various rectangular ...
uhoh's user avatar
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3 votes
2 answers
402 views

Has "parasitic radar" ever been used in space?

Synthetic aperture radar or SAR is becoming a hot field of Earth observation of both natural and human activity. It is very power hungry as the beam needs to deliver sufficient power over each square ...
uhoh's user avatar
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2 votes
1 answer
286 views

Suppose I wanted to compare TLEs to actual LEO satellite positions, what data is available? From which may it be easiest to extract X, Y, Z, T points?

Under @RyanC's answer to How can I plot satellite's trajectory from three different TLEs to detect any deviation on path with time? I wrote: I think that SGP4 + TLEs is so popular because the TLEs ...
uhoh's user avatar
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7 votes
2 answers
297 views

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

I was wondering; if all Starlink satellites had high-end cellphone quality cameras modules on simple telescopes, could the resulting images be combined and processed in such a way that a super-...
AggroFrizzy's user avatar
3 votes
0 answers
84 views

Given 10W and a 100 m^2 target to look for from LEO, which can search a larger area; SAR or LIDAR? (back of spherical cow-shaped envelope question)

Background For the project discussed in Space based active optical sensors for maritime surveillance the concern seems to be that SAR is off the table because a low inclination orbit is in eclipse ...
uhoh's user avatar
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5 votes
1 answer
909 views

what is revisit rate

I want to understand what the revisit rate is. If the payload is required to make the revisit rate of 5 hours. The orbit is LEO (altitude less than 2000 kms). What does this mean? Revisit time - the ...
geetha's user avatar
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0 votes
2 answers
124 views

First cylindrical Earth satellite? Last?

Sputnik 1 was a shiny metal sphere, as were it's immediate followers. These days Earth satellites are generally rectangular prisms, either one or a few stuck together. Basically big metal chassis ...
uhoh's user avatar
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3 votes
1 answer
122 views

How do I get the Landsat satellite's images of the Earth?

I want to get the database of the images taken by Landsat satellite of Earth for a project. I searched and searched and searched, but
Robo's user avatar
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-1 votes
1 answer
137 views

Why is Aurora Australis less popular? [closed]

The Aurora Borealis(Northern Lights), in the North, gets more publicity, than the (Southern Lights) Aurora Australis, Why is it so?
sam2611's user avatar
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1 vote
0 answers
63 views

Was CloudSat hit by debris? If so, when, how bad was it, and where was it reported?

Anton Petrov's new video Another Satellite Collided in Space, But Everyone Missed It Until Now (below) is fun to watch, and links to Jonathan McDowell's tweet string which begins Space-Track catalog ...
uhoh's user avatar
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5 votes
0 answers
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How does ECOSTRESS measure both temperature and emissivity of the Earth's surface simultaneously? (Science package aboard the ISS)

The This Week at NASA video A U.S. Commercial Spacecraft Departs the Space Station on This Week @NASA – July 2, 2021 includes the following quote: Data from NASA’s Ecosystem Spaceborne Thermal ...
uhoh's user avatar
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11 votes
1 answer
830 views

Star-shaped artifacts in SAR images of the "Suez Canal traffic jam seen from space"

Wikipedia's 2021 Suez Canal obstruction links to the Sentinel-1 synthetic aperture radar (SAR) image of the Traffic jam in the Gulf of Suez caused by the obstruction as seen by the Sentinel-1 ...
uhoh's user avatar
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4 votes
3 answers
243 views

Why can Amazônia-1 observe the Amazon "every day or two" while Landsat takes 16 days between observations? Is "orbital magic" at play here?

The news item in Science Brazil’s first homemade satellite will put an extra eye on dwindling Amazon forests says: Right now, Brazil’s Amazon monitoring program relies on flyovers from the U.S. ...
uhoh's user avatar
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69 votes
4 answers
11k views

Why did it take so long to notice that the ozone layer had holes in it? Which satellite provided the data?

Wikipedia says: The discovery of the annual depletion of ozone above the Antarctic was first announced by Joe Farman, Brian Gardiner and Jonathan Shanklin, in a paper which appeared in Nature on May ...
uhoh's user avatar
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13 votes
1 answer
1k views

What is your name? What is your quest? What is the story behind Satellite 1963-38C?

Source see also the page On Possible Electric Phenomena in Solar Systems and Nebulae By Kristian Birkeland extracted from The Norwegian Aurora Polaris Expedition 1902-1903 (Book) Wikipedia's ...
uhoh's user avatar
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20 votes
2 answers
4k views

What is the name of the area on Earth which can be observed from a satellite?

The following image shows Earth and the trajectory of the ISS. A green line indicates which part of the earth can be observed from the ISS simultaneously. What is the name of this line or this area?
rul30's user avatar
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2 votes
1 answer
202 views

Why was Voskhod 1 at an inclination of 64.7° degrees while Salyut 6 launched from the same latitude was at 51.7°?

This answer to Have any Soviet-era astronauts reported seeing Earth's aurora or related luminescent atmospheric effects? mentions sightings from both Salyut 6 and Voskhod 1. While Salyut 6 orbited for ...
uhoh's user avatar
  • 149k
3 votes
1 answer
614 views

Have any Soviet-era astronauts reported seeing Earth's aurora or related luminescent atmospheric effects?

Earth's aurora and related luminescent atmospheric effects are generally quite dim, and mostly but not always located in the general area of Earth's magnetic poles. That means to be seen easily by eye ...
uhoh's user avatar
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1 vote
0 answers
205 views

Have any Apollo (or earlier) astronauts reported seeing Earth's aurora or related luminescent atmospheric effects?

Earth's aurora and related luminescent atmospheric effects are generally quite dim, and mostly but not always located in the general area of Earth's magnetic poles. That means to be seen easily by eye ...
uhoh's user avatar
  • 149k
1 vote
3 answers
781 views

Satellite inclination, 3D scanning of earth's surface

Has any attempt been made to change the "plane" of the orbit (not altitude) of a satellite, across earth's diameter, continuously in small steps, from pole to pole for a satellite with zero ...
Niranjan's user avatar
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1 vote
1 answer
99 views

Why does OGO-1's trajectory and imminent reentry come from sky surveys and NEO tracking rather than normal satellite tracking?

Space.com's 56-year-old NASA satellite expected to fall to Earth this weekend says: "OGO-1 is predicted to re-enter on one of its next three perigees, the points in the spacecraft's orbit ...
uhoh's user avatar
  • 149k
5 votes
1 answer
418 views

How many (presumably friendly) lasers are being shot at us from space? (pew! pew!)

Example: at first they could not decide which of the green laser-shooting satellites was responsible! Too many to choose from? See Science Alert's February 9, 2023, Ominous Green Lasers Shot Over ...
uhoh's user avatar
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7 votes
2 answers
442 views

What exactly gives a larger field of view to the donated "spy" telescopes that NASA may send to Mars? How much larger?

This answer to Could one of the interstellar probes discover Planet IX by accident? links to Space.com's NASA May Launch Donated Spy Satellite Telescope to Mars which says: An unexpected gift The two ...
uhoh's user avatar
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4 votes
1 answer
451 views

Is Earth's "pear shape" mostly J₃?

@OrganicMarble's answer to 1959 Peanuts cartoon about the Fischer ellipsoid (Earth is “pear-shaped”)? finally let me see the cartoon that Mathematician, Engineer and Geoscientist Irene Fischer wrote ...
uhoh's user avatar
  • 149k
3 votes
1 answer
100 views

Why will it take a couple of weeks to complete CRYOSAT 2's orbit raising of a few hundred meters?

The BBC's Esa and Nasa line up satellites to measure Antarctic sea-ice says: Authorisation was given on Tuesday for Europe's Cryosat-2 spacecraft to raise its orbit by just under one kilometre. This ...
uhoh's user avatar
  • 149k
1 vote
1 answer
235 views

Why are ICESAT-2 and CRYOSAT 2 both at inclinations of almost exactly 92 degrees?

The BBC's Esa and Nasa line up satellites to measure Antarctic sea-ice says: Authorisation was given on Tuesday for Europe's Cryosat-2 spacecraft to raise its orbit by just under one kilometre. This ...
uhoh's user avatar
  • 149k
1 vote
0 answers
78 views

Why no Ofeqs between 11 and 16?

Wikipedia's Ofeq; Launch History lists Ofeq 1 through 11 and then 16. It does not mention a 12, 13, 14 or 15. Were they so stealthily launched that nobody knows about them, or skipped, had non-Ofeq ...
uhoh's user avatar
  • 149k
13 votes
1 answer
2k views

At what minimum distance does the Earth appear star-like to the naked eye?

At what distance does the Earth become indistinguishable from stars and other planets to the naked eye, like the Pale Blue Dot or like Venus or Mars visible from Earth? Dot-like rather than spherical. ...
LoveForChrist's user avatar
19 votes
1 answer
2k views

When did photographic film stop being used in satellites?

Some early observation satellites took pictures on photographic film and the film was dropped towards Earth and picked up by airplanes (e.g. Corona). What was the last satellite to use photographic ...
usernumber's user avatar
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0 votes
0 answers
53 views

Where are post-2017 EPIC images of Earth and the DSCOVR spacecraft coordinates available for download?

I tried to download orbital positions for the DSCOVR spacecraft in its Lissajous orbit around Sun-Earth L1 from JPL's Horizons web page but I was surprised to see the following! No ephemeris for ...
uhoh's user avatar
  • 149k
1 vote
0 answers
62 views

HDEV Goodbye Video- similar projects planned?

I just found that nice "Goodbye HDEV" video on the Columbus-Eye-Projekt-Webpage. (http://columbuseye.rub.de/) Seems like the HDEV-housing is already burned during re-entry. Does anyone know ...
Spacecrafticus's user avatar
2 votes
1 answer
131 views

What routinely happened in the TIROS control center? Was anything controlled there?

Question: What actually happened in the TIROS control center at Goddard Space Flight Center, Greenbelt, Maryland? Did they receive and print out satellite images in this room? If so, how? Did they ...
uhoh's user avatar
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2 votes
0 answers
495 views

What does a typical delta-v budget look like for a LEO satellite?

In terms of launch, initial orbit correction, stationkeeping, deorbiting, etc. for a typical 100-200 kg LEO satellite? Is there any source online with specifications for non-private Earth-orbiting ...
Paek Se's user avatar
  • 362
7 votes
1 answer
178 views

Do crew movements or movement of other objects ever affect space or Earth observation experiments staged on the outside of ISS?

The ISS serves as a platform for both Earth and astronomical observational instrumentation. Do routine movements of the crew or other objects ever cause problems for these observations through ...
uhoh's user avatar
  • 149k
12 votes
3 answers
1k views

Do Starlink satellites have cameras?

Obviously, Starlink satellites are equipped with sensors for attitude and location detection (like a star tracker or sun tracker) but I'm wondering if they have with any direct Earth observation ...
Dragongeek's user avatar
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1 vote
1 answer
141 views

How will NASA's TROPICS cubesats be inserted into their three orbital planes and proper phasings?

Rocket to launch 8 cubesat to LEO at an equidistant distance reminded me that I'd never asked this question. NASA's TROPICS 3U cubesat constellation hasn't been launched yet, so there's still time to ...
uhoh's user avatar
  • 149k
8 votes
2 answers
601 views

How were video tape recorders adapted to work in orbit in 1962?

Livescience's Satellite spies gigantic 'fuzzball' clouds spreading near Australia coast says: Actinoform clouds were first captured by NASA’s Television Infrared Observation Satellite V in 1962, but ...
uhoh's user avatar
  • 149k
8 votes
1 answer
1k views

Why does Himawari-8 have problems with the Sun from 19th February to 19th April?

This weather site uses provides meteorological imaging from the Himawari-8 Earth observing satellite in GEO. https://www.cwb.gov.tw/eng/ The web site contains the following item: ...
uhoh's user avatar
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2 votes
1 answer
1k views

Why is there no image of the Earth taken from the lunar surface during Apollo 12,15 and 16?

I know there are photographs of the Earth from the lunar surface taken during Apollo 11, 14 and 17. Here are some for reference (there are many for Apollo 17). Apollo 11 (AS11-40-5923): Apollo 14 (...
Star Man's user avatar
  • 5,908
7 votes
1 answer
267 views

How was motion blur mitigated in the early Earth-observation satellites?

The Corona Photographic Surveillance Satellite had one (later two) panning cameras for observations: (Cameras on Corona - source) The cameras panned over a 70 degree arc perpendicular to the flight ...
Ludo's user avatar
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