Salt Lake City from LandSat 15
Radiogal writes: "A great view of the area from NASA! See olympics.gsfc.nasa.gov." This is about all of the Olympics you're going to see on the web. :)
God help those who do not help themselves. -- Wilson Mizner
All right! (Score:1)
Pictures like this are a real neat use of satellites, even if they don't serve very much 'purpose' (well, in this case). Wonder what it would cost to set up a stream of this view during the olympics? Would that violate any 'single broadcaster' agreement?
Re:All right! (Score:2)
Now, I know you meant that comment as a joke, but it was in poor taste.
The satellites used to take these photos are in low earth orbit. This means they complete one orbit in roughly two or three hours. You really can't get a live video feed covering one geographic region for an extended period of time. Sorry
Re:All right! (Score:2, Informative)
http://earthobservatory.nasa.gov/Library/AM1/ [nasa.gov]
http://earthobservatory.nasa.gov/Library/Landsat/ [nasa.gov]
and in response to the target remark, we are no longer allowed to post labelled satellite images of NASA centers.
More cool related imagery (shameless plug): http://earthobservatory.nasa.gov/Newsroom/BlueMar
I can see my house from here! (Score:1, Funny)
More content coming Friday (Score:2, Informative)
What surprises me... (Score:1)
From the air (Score:2)
you can't see all the filth that I trudge through at the university of utah on a daily basis.
You can't see much from space this week.. the temperature inversion is awful. You can't even see our beautiful mountains.
Temperature Inversions (Score:4, Informative)
You can't see much from space this week.. the temperature inversion is awful. You can't even see our beautiful mountains.
For any of you who are wondering what flikx is talking about:
The Salt Lake Valley is surrounded on the east and the west by tall mountains, and the exits from the valley on the north and south are relatively narrow. The effect is almost like a big bowl. Fairly frequently during the winter a pocket of warmer air gets trapped in the bowl underneath a layer of cold air. This situation is called a temperature inversion.
The problem with this situation is that the cold air acts like a lid on the valley, trapping all of the smog produced by cars, refineries, factories, etc. When this situation persists for more than a few days it can get pretty bad. Not L.A. kind of bad, but thick enough that it does ruin the view, and bad enough that use of wood-burning stoves and fireplaces are disallowed to help keep us from exceeding EPA regulations on particulate matter (and we still do, at times). The haze stays high enough that it doesn't really affect people, just the visibility.
Unfortunately, after several weeks of record cold, but quite clear, weather, an inversion began a few days back, and there's no telling how long it will persist. Up in the mountains at the ski resorts where the downhill events are will be clear and typically beautiful, but the medals plaza, skating rinks, hockey, etc. will be shrouded in brown smog.
Too bad, really, but there's nothing to be done. A good snowstorm will both scrub the haze from the air and has a good chance of breaking the inversion, so that's our best hope. There is a storm on the forecast for Friday morning, which would be perfect. The view of the mountains from the valley is absolutely spectacular when the air is clear.
Re:Temperature Inversions (Score:3, Informative)
Re:Temperature Inversions (Score:2)
I don't know about that. Having lived in LA for 2 years and near SLC for a long time, my judgement is that it DOES get "LA kind of bad" sometimes. "Hazy Shade of Winter" must have been written for Utah between November and March.
The only difference is LA is hazier in the summer, and Utah is hazier in the winter. Solution: live in So. Cal in winter, Utah in Summer. Yep.
Very Cool (Score:1)
Hubbel telescope (Score:2)
Re:Hubbel telescope (Score:1)
Re:Hubble telescope (Score:1)
Here's a short summary: Why The Hubble Space Telescope Went Wrong [uoguelph.ca]
Re:Hubble telescope (Score:3, Insightful)
The technical management of two groups of people had to fail to enable construction of the original "myopic" Hubbell telescope. The government group which contracted with the supplier had to overlook the rather obvious short fall of the borrowed design. Second, the supplier, who had performed the design originally for near field operation, either overlooked the design shortfall or, more likely, had lost the organizational technical legacy of the original design team which would have stopped or attempted to stop the Hubbell "borrowed design" project before it started.
The design criteria for the original optical design for the telescope was based on imaging features on the surface of the earth from a low earth orbit reconnaissance satellite. The potential performance of surveillance systems of this type had been detailed in JOSA in the mid 60s. The performance limitation of an imaging system in earth orbit was shown by Hufnagel of Perkin Elmer to be the modulation transfer function (MTF) of the atmosphere which veils the surface of the earth as viewed from space. In his paper Hufnagel performed trades which related performance to altitude and diameter of the optical system. To achieve the nominal 1 microradian resolution which he projected would require a nominal 2 meter diameter optical system. It is a small step from this fact to the requirement to have a telescope with a customized figure for near field operation. The 2.5 meter aperture used would have to operate at or very near it's diffraction limit of 0.5 microradian to achieve the performance as limited by the atmosphere. To achieve very near diffraction limited performance the optical figure would definitely have to be adjusted to accommodate the large sag, spherical input wavefront.
The production of optics generally requires the building of tooling, test jigs and test plates to insure that the finished product has been correctly produced. The development, building and testing of this tooling is a major part of the expense of producing optical systems. This was, apparently, a major "cost saving" envisioned for the original Hubbell project. The tooling for a telescope designed to operate in the near field was employed to build a telescope to view stars at optical infinity. During initial operation of the Hubbell after being deployed into orbit it's designed-in "myopic" condition was discovered.