Author Topic: SpaceX Falcon 9 - DSCOVR - SLC-40, Cape Canaveral - Feb 2015 - DISCUSSION THREAD  (Read 652568 times)


Offline Lars-J

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New images/video from DSCOVR - showing its first view of the Moon passing in front of our planet!

http://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth (video in article)

Online matthewkantar

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New images/video from DSCOVR - showing its first view of the Moon passing in front of our planet!

http://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth (video in article)

This is an astounding picture. I notice Baha has a cyclone nearby. What are the green flashes at the leading limb of the Moon? Atmosphere? Dust particles? Camera artifact?

Enjoy, Matthew

Offline JBF

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New images/video from DSCOVR - showing its first view of the Moon passing in front of our planet!

http://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth (video in article)

This is an astounding picture. I notice Baha has a cyclone nearby. What are the green flashes at the leading limb of the Moon? Atmosphere? Dust particles? Camera artifact?

Enjoy, Matthew

Camera effect.  [strike]DSCOVR takes 3 filtered pictures then combines them. So you get green on one side and red on the other due to the shutter speed vs moon transit time.[/strike]

edit: see below for a more accurate explanation.
« Last Edit: 08/05/2015 08:51 pm by JBF »
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Offline kevin-rf

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Small nit, most likely the readout time of the CCD sensor, not the shutter time. Also, the filter wheel has 10 spectral bands (filters)

It's a 2kx2k CCD, depending on the AtoD speed, it may take several seconds to readout the sensor between frames. It's not uncommon for 16bit CCD AtoD's to use 100Khz (100,000 pixels a second) readout rates to reduce readout noise. A 100Khz AtoD chain would be 40 seconds between images, a 1 MHz AtoD chain would be 4 seconds between images... Anyone have a fact sheet on the EPIC?

http://www.nesdis.noaa.gov/DSCOVR/pdf/DSCOVR%20-%20EPIC%20Instrument%20Info%20Sheet.pdf

Quote
The time cadence will be no faster than 10 spectral band images every hour.

So your talking a min of 6 minutes between color bands, meaning at least 6 minutes between images.
« Last Edit: 08/05/2015 08:15 pm by kevin-rf »
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Offline ClayJar

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Quoting from the article:
Quote
Combining three images taken about 30 seconds apart as the moon moves produces a slight but noticeable camera artifact on the right side of the moon. Because the moon has moved in relation to the Earth between the time the first (red) and last (green) exposures were made, a thin green offset appears on the right side of the moon when the three exposures are combined. This natural lunar movement also produces a slight red and blue offset on the left side of the moon in these unaltered images.

Offline Comga

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Remember, the purpose of EPIC is to take color images of the Earth.
The Field of view is just large enough to accomplish that with pointing tolerances. The scale maximizes the resolution and the resulting vignetting, the circular limit on the image, doesn't interfere with the purpose.
Similarly the imaging speed is enough for the rotating Earth without artifacts but not enough to image the transiting Moon without them because the former is its purpose and the latter is not.
Choices have to be made in engineering.
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Offline Star One

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Remember, the purpose of EPIC is to take color images of the Earth.
The Field of view is just large enough to accomplish that with pointing tolerances. The scale maximizes the resolution and the resulting vignetting, the circular limit on the image, doesn't interfere with the purpose.
Similarly the imaging speed is enough for the rotating Earth without artifacts but not enough to image the transiting Moon without them because the former is its purpose and the latter is not.
Choices have to be made in engineering.

But it does make the images look very flat, they appear as if paper cutouts.

Online matthewkantar

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The five posts above in response to my question about the green glow are very satisfying, thanks all for taking a minute to inform me and the site.

Matthew

Offline Lars-J

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Remember, the purpose of EPIC is to take color images of the Earth.
The Field of view is just large enough to accomplish that with pointing tolerances. The scale maximizes the resolution and the resulting vignetting, the circular limit on the image, doesn't interfere with the purpose.
Similarly the imaging speed is enough for the rotating Earth without artifacts but not enough to image the transiting Moon without them because the former is its purpose and the latter is not.
Choices have to be made in engineering.

But it does make the images look very flat, they appear as if paper cutouts.

That's because we are viewing things from the sun's point of view. (or very near to it) Everything WILL look flat.

Offline rpapo

Think telephoto, because the angular field of view here is very narrow.
Following the space program since before Apollo 8.

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NASA Launch DSCOVR "webcam" type site:

http://epic.gsfc.nasa.gov/


Offline the_other_Doug

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NASA Launch DSCOVR "webcam" type site:

http://epic.gsfc.nasa.gov/

Must have had a roll-out glitch; came up with a "Web Page Not Available" message for quite a while, then spontaneously loaded.

Maybe Gore was right, and having an up-to-date full disk Earth image will be popular and inspiring...  At any rate, I was able to pull down an image of my home hemisphere (western) as it appeared during mid-day on my 60th birthday, two days ago.

I truly like that.

Edit -- I reformatted for my HD-sized monitor.  Here is the Earth exactly 60 turns around the Sun after I was born.
« Last Edit: 10/20/2015 03:59 pm by the_other_Doug »
-Doug  (With my shield, not yet upon it)

Offline MattMason

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You can get a nice animation that combines several EPIC images to form a full rotation of the Earth through the NOAA/NASA site in lieu of the still-down EPIC website.
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Offline OneSpeed

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NASA Launch DSCOVR "webcam" type site:

http://epic.gsfc.nasa.gov/

The site appears at least partly functional at the moment. Eight images from Australia westward to Africa are available. The weather pattern over South Australia suggests the first image is about 24 hours old, as does the file name.
« Last Edit: 10/21/2015 12:43 am by OneSpeed »

Offline ZachS09

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Wow. Those images look amazing. Better than Apollo 17's "Blue Marble".  :D
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Offline CyndyC

Email alert from the Space Weather Prediction Center (SWPC) of NOAA, the latter by the way run by one of NASA's first six women in space and the first American woman to EVA, Dr Kathryn Sullivan:

Quote
Beginning at Noon EDT (1600 UTC) on Wednesday, July 27, 2016, SWPC will start using data from NOAA’s Deep Space Climate Observatory (DSCOVR) spacecraft in its operations. This data will replace the data currently provided by the ACE satellite. Details can be found on the SWPC website.

27 July 2016 it’s all systems go for NOAA’s first deep space weather satellite
« Last Edit: 06/27/2016 01:45 am by CyndyC »
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Offline Star One

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NASA's EPIC view spots flashes on Earth

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Another feature of the EPIC data helped confirm that the flashes were from a high altitude, not simply water on the ground. Two channels on the instrument are designed to measure the height of clouds, and when the scientists went to the data they found high cirrus clouds, 3 to 5 miles (5 to 8 kilometers) where the glints were located.

"The source of the flashes is definitely not on the ground. It's definitely ice, and most likely solar reflection off of horizontally oriented particles," Marshak said.

Detecting glints like this from much farther away than in this case could be used by other spacecraft to study exoplanets, he said. As an Earth scientist, however, Marshak is now investigating how common these horizontal ice particles are, and whether they're common enough to have a measureable impact on how much sunlight passes through the atmosphere. If so, it's a feature that could be incorporated into computer models of how much heat is reaching and leaving Earth.

https://www.eurekalert.org/pub_releases/2017-05/nsfc-nev051517.php
« Last Edit: 05/17/2017 04:51 pm by Star One »

Offline CorvusCorax

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DSCOVR went into safe mode in July 2019 due to RCS issues

https://spacenews.com/dscovr-spacecraft-in-safe-mode/

NASA & NOAA had since attempted to get the satellite back online, which according to the same site

https://www.space.com/dscovr-earth-space-weather-satellite-back-online.html

was successful yesterday. DSCOVR is back on-line

I couldn't find the active update thread for that mission though.


Edit: Finally found the operational mission thread. https://forum.nasaspaceflight.com/index.php?topic=37745.0
This forum really needs a better search function.
Suggestion:
When searching for search term X:
1. Put Results with term X in topic title above those of posts where X is referenced in the text or even in someones signature
2. With otherwise equal dominance, make newer post more relevant than older posts.
3. Do not return an empty result set every 2nd search.
« Last Edit: 03/08/2020 01:04 pm by CorvusCorax »

Online gongora

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https://twitter.com/shell_jim/status/1360231046747361285
Quote
Cislunar object recovered. TLE for Falcon 9 rocket body (40391 / 2015-007B) used to launch DSCOVR in 2015 updated - last update was >5 yrs ago. Great job @18SPCS ! Alas, normal Type 0 TLEs will not propagate well for this orbit, but hopefully the object will now be maintained.
« Last Edit: 02/12/2021 05:36 pm by zubenelgenubi »

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