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Nighttime with CA-LIPSO

Posted: Wed May 26, 2010 4:45 pm
by neufer
http://earthobservatory.nasa.gov/IOTD/view.php?id=44052 wrote:
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Nighttime Ash Tracking with CALIPSO (May 16, 2010)

<<Many satellites can provide a bird’s-eye view (such as the top, nighttime image) that can identify thick plumes of ash, but few satellites can tell how high the ash is in the atmosphere. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite, however, records a vertical profile of the atmosphere, which reveals the altitude of ash clouds, shown in the lower image. These observations help modelers in volcanic ash advisory centers improve forecasting models and issue more accurate warnings to pilots and others with aviation interests.>>
http://en.wikipedia.org/wiki/Calypso_%28mythology%29 wrote:
<<Calypso (Greek: Καλυψώ ), a.k.a., Atlantis (Ατλαντίς). was a sea goddess daughter of the Titan Atlas. Calypso is remembered most for her role in Homer's Odyssey, in which she imprisons the fabled Greek hero Odysseus on her island in order to make him her immortal husband.

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Calypso kept Odysseus hostage at Ogygia (Gozo?) for seven years. Odysseus, however, wants to return home to his beloved wife Penelope. His patron goddess Athena asks Zeus to order the release of Odysseus from the island, and Zeus sends Hermes to tell Calypso to set Odysseus free. According to Hesiod, Calypso bore Odysseus two children, Nausithous and Nausinous.

Nausea, n. [L., fr. Gr. , fr. ship. See Nave of a church.] Seasickness; hence, any similar sickness of the stomach accompanied with a propensity to vomit; qualm; squeamishness of the stomach; loathing.>>

Re: Nighttime with CA-LIPSO

Posted: Mon Jun 07, 2010 3:46 am
by alter-ego
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Lips like those you'll only find on the A-Train.
http://www-calipso.larc.nasa.gov/about/atrain.php

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Re: Nighttime with CA-LIPSO

Posted: Wed Aug 24, 2011 4:08 pm
by neufer
http://en.wikipedia.org/wiki/CALIPSO wrote:
<<CALIPSO is a joint NASA (USA) and CNES (France) environmental satellite, built in the Cannes Mandelieu Space Center, which was launched atop a Delta II rocket on April 28, 2006. Its name stands for Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations. Passive and active remote sensing Instruments on board the CALIPSO satellite will monitor aerosols and clouds 24 hours a day. CALIPSO will fly in formation in the "A Train" with several other satellites (Aqua, Aura, CloudSat and the French PARASOL).

Instruments:
  • 1) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) - a lidar that provides high-resolution vertical profiles of aerosols and clouds.
    2) Wide Field Camera (WFC) - a modified version of the commercial off-the-shelf Ball Aerospace CT-633 star tracker camera. It was selected to match band 1 of the MODIS instrument on the Aqua satellite.
    3) Imaging Infrared Radiometer (IIR) - used to detect cirrus cloud emissivity and particle size. The CALIOP laser beam is aligned with the center of the IIR image to optimize joint CALIOP/IIR observations.
In February 2009, CALIPSO switched over to the redundant laser as scheduled. The primary laser achieved its mission goal of three years of successful operation. The redundant laser has been performing beyond expectations. The CALIPSO mission was granted extended mission status in June 2009.>>
http://www-calipso.larc.nasa.gov/ wrote:

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<<In the days and weeks before the monsoon, heat builds over India. Hot air rises over the baked earth and westerly winds rush in to fill the void, bringing dust-laden air from the deserts of southwest Asia and the Arabian Peninsula. Through April, May, and June, as monsoon conditions build, the air over the Ganges River plain grows thick with dust, smoke, and haze. Air quality over India is at its worst at this time of year. Finally, in mid- to late-June, the winds shift and cleansing monsoon rains fall.

This image provides a profile of the pre-monsoon air over India on May 12, 2007. The lower image was made with data from the CALIPSO satellite, which sends pulses of laser light through the atmosphere at night and measures the light signal that returns to the sensor. This measurement reveals the concentration of particles—ice, dust, soot, and so forth—in the atmosphere. The dark orange areas in the profile show where the particle concentration was most dense. Pale orange and white reveal fewer particles.

The top image is a daytime scene captured that same day by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite. The yellow line across the top image shows the path of the satellite on May 12 when it collected the profile in the lower image.

The dense particle concentration included a combination of dust, smoke from fires, and urban smog. Measurements from other satellites and ground-based instruments revealed that the bulk of the pollution was dust.

Dust carried on westerly winds moves over the Gangetic Plain and hits a barrier: the massive Himalayas. Trapped against the mountain front, the dust builds until concentrations are higher than at any other time of year. The rising of hot air from the land, combined with the incoming winds, push the dust and haze high into the atmosphere along the front of the Himalaya. In this image, the bulk of the dust reaches about four kilometers in altitude; along the mountains, it reaches six to seven kilometers. (The particles over the mountains and the Tibetan Plateau are probably ice clouds, but may also contain some dust.)

This dust and haze over the Ganges Plain may increase the intensity of monsoon rains. The dust particles and soot both absorb energy, heating the atmosphere. The added heat pushes the air higher than it would otherwise rise. The rising air sucks up more air, and when that air is moist, the monsoon circulation may strengthen, leading to more rainfall during the early summer.

The high dust and haze also might hasten the melting of snow in the Himalayas. Particles settle on the surface, darkening the snow. White snow reflects energy, but the particle-darkened surface absorbs it, causing the snow to melt faster. This has been demonstrated in other regions.>>

Re: Nighttime with CA-LIPSO

Posted: Fri Aug 26, 2011 5:48 am
by alter-ego
3 Billion Images!
This is a big deal for a space-based laser system.
CALIPSO 3 Bilion Images.JPG
Are You a Satellite Hunter?
CALIPSO consists of a laser that emits two wavelengths: 1064nm and its 2nd harmonic, 532nm. Satellite based laser sources have also shown some promise as photometric calibration sources for ground-based telescopes. CALIPSO's green beam is visible to the eye, but there's a good chance you will miss it. Here are the parameters and criteria you should know:
- Repetition rate = 20.16Hz
- Footprint separation (on the ground) ~330 meters
- Visible footprint size ~150 meters to 200 meters
- Satellite ground track accuracy ~100 meters at best (need to use most recent oribital parameters to get that accuracy)
- Likely possible to see footprint on high, thin-layer cirrus-like clouds (this was true for ICESAT), but near zenith viewing is needed
(See linked paper above)
(See linked paper above)
A couple tips:
Multiple observers and/or cameras can increase the chance of visibility
PATIENCE. CALIPSO will pass over near you and road that will access the ground track location. There may be many weeks before a suitable chance arises, especially if you don't want to drive too far :ssmile: