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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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31 views

Given 10W and a 100 square meter target to look for, 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 ...
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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 ...
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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 ...
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1answer
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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
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1answer
93 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?
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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 ...
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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 ...
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1answer
318 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 ...
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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. ...
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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 ...
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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 ...
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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?
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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 ...
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605 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 ...
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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 ...
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3answers
647 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 ...
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1answer
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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 ...
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How many (presumably friendly) lasers are being shot at us from space? (pew! pew!)

A comment below @A.Rumlin's answer to Is there any spacecraft that is ping-able? links to a Facebook page (in Russian) which shows an astrophotographer's photograph of stars plus a big green flare ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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. ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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: ...
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399 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 (...
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201 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 ...
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Is TEMPO firmly planned to be launched?

The Tropospheric Emissions: Monitoring POllution (TEMPO) instrument (see Smithsonian Institute, EO Portal, or WMO Oscar) is supposed to measure air pollution over North America from a geostationary ...
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251 views

How exactly does atomic oxygen cause problems for spacecraft in VLEO?

In very low Earth orbit there are (at least) two problems; aerodynamic drag, and atomic oxygen (O rather than O2). Drag can be compensated with a low thrust from an ion engine. Question: But what ...
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Were there problems for "NASA’S ICON satellite"? Did PG&E shut off UC Berkeley's Space Sciences Laboratory's power?

The San Jose Mercury News article How PG&E’s power shutdown threatened a NASA mission describes a last minute rush to obtain extension cords, generators, and access to backup fuel when it was ...
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Could Apollo astronauts see city lights from the moon?

You can see city lights from orbit on the night side of Earth. A lot of science fiction (yes, sorry...it's one of those questions) has dialogue such as "on a clear night you can see XYZ city on the ...
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Has anyone in space seen or photographed a simple laser pointer from Earth?

In the question How to make a green LED as visually bright as a 0 magnitude star? I worked out that a 100 mA green LED with a 10° half-angle 18 kilometers away would be as bright as a 0th magnitude ...
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Why is the Aeolus space laser losing power so quickly?

The BBC News article Aeolus: Wind-mapping space laser is losing power says that Europe's Aeolus satellite was launched last year to gather data to improve weather forecasts, and its observations have ...
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1answer
272 views

Why does the Earth's atmosphere as seen from space have the colors that it does?

Here is a photo of Comet Lovejoy taken from orbit. https://spaceflight.nasa.gov/gallery/images/station/crew-30/html/iss030e015472.html The atmosphere has 3 bands. The lowest is deep blue and so I ...
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1answer
124 views

Roughly what fractions of the time did Skylab spend in Earth-oriented and Sun-oriented attitudes?

The Introduction section of NASA Technical Memo TM-X-64628 Angular momentum desaturation for Skylab using gravity gradient torques begins: The Skylab Apollo Telescope Mount (ATM) experiments require ...
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2answers
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Why are images from DSCOVR EPIC unavailable for certain dates?

I am in love with the images available at https://epic.gsfc.nasa.gov/ taken from the DSCOVR satellite. I am curious though as to why some dates are unavailable to select. The calendar date picker ...
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370 views

How was the 18 December 2018 Bering Sea Fireball detected and characterized? Was it a serendipity or a weather satellite?

The map at Fireball and Bolide Data is reproduced in the BBC News article US detects huge meteor explosion with the 2013 Chelyabinsk event and the recent 18-Dec0281 Bering Sea event annotated. The ...
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1answer
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Why can Cryosat's dual antenna "better discern steep slopes" of Antarctic ice than Sentinel-3?

The BBC's Climate change: Satellite fix safeguards Antarctic data explains that earlier problems of missing data near the coasts have been addressed, and though scientists are hopeful, there is ...
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222 views

Would a space station be able to watch a world wide cataclysm and how long would the crew be able to survive for? [closed]

I know there is other questions with similar concerns about there being any protocols in pace if the crew of space station were to witness a world wide cataclysm and the survivability of the crew if ...
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1answer
1k views

Cost of an earth observation cubesat satellite like Planet Labs' Doves?

With the cubesat standard and more and more components being available off the shelf, this should really bring down the price of building a (simple) earth observation platform. I am curious how low a ...
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156 views

Which spacecraft can see plants "glow" during photosynthesis during the day, and what wavelength does it use?

This comment reminded me that I once read something about an Earth observation satellite that has a sophisticated optical system (possibly a camera) that it tuned to a very narrow range of wavelengths ...