How big is the QuikSCAT satellite?
1 m diameter
Figure 14: Schematic view of the SeaWinds scatterometer elements (image credit: NASA/JPL)
| Radar | 13.4 GHz (Ku-band); 110 W pulse at 189 Hz PRF |
|---|---|
| Antenna | 1 m diameter rotating dish that produces two spot beams, sweeping in a circular pattern |
| Swath width | 1800 km (providing about 90% of temporal Earth coverage every day) |
When was the QuikSCAT launched from?
June 19, 1999QuikSCAT / Launch date
What is the satellite Nscat used for?
NSCAT provides continuous measurements of ocean surface wind speeds from space, which will help meteorologists better predict the behavior of storms. Data like these are being used by the National Weather Service, an agency of the National Oceanic and Atomospheric Administration in their global forecast models.
How does a satellite scatterometer work?
Scatterometers are active remote sensing instruments for deriving wind direction and speed from the roughness of the sea. They are used by low Earth orbiting satellites and act like radars: they transmit electromagnetic pulses and detect the backscattered signals.
How has satellite technology helped the study of oceanography?
Satellites also provide information about the color of the ocean. For example, color data helps researchers determine the impact of floods along the coast, detect river plumes, and locate blooms of harmful algae that can contaminate shellfish and kill other fish and marine mammals.
Is scatterometer active or passive?
It is an example of an “active” microwave radar instrument, operating by transmitting pulses of microwaves at the ocean surface and then measuring the scattering of the return reflection by capillary waves, small ripples that form right on the surface in response to the wind.
What is advanced scatterometer?
The Advanced Scatterometer (ASCAT) is one of the new-generation European instruments carried on MetOp and will be used to determine information about the wind for use primarily in weather forecasting and climate research.
How do satellites measure ocean depth?
Satellite radar altimeters measure the ocean surface height (sea level) by measuring the time it takes a radar pulse to make a round-trip from the satellite to the sea surface and back. Bathymetry is measurement of the depth of the ocean.
How do satellites measure ocean surface height?
Measurement. The sea surface height (SSH) is calculated through altimetry satellites using as a reference surface the ellipsoid, which determine the distance from the satellite to a target surface by measuring the satellite-to-surface round-trip time of a radar pulse.
What are the three remote sensing tools?
Here are some of the common sensor technologies:
- Light Detection and Ranging (LiDAR)
- Sound navigation ranging (Sonar)
- Radiometers and spectrometers.
What is Ascat weather?
The Advanced Scatterometer (ASCAT) winds products are processed by NOAA/NESDIS utilizing measurements from the scatterometer instrument aboard the EUMETSAT Metop satellites. The instrument uses radar to measure backscatter to determine speed and direction of winds over the surface of the oceans.
What is the unit of measure for depth of sea?
fathom
Water depths are measured by soundings usually acquired by hydrographic surveys. The depths may be in either feet or fathoms (the chart will indicate which). A fathom is a nautical unit of measurement and is equal to six feet. Sonar devices are used to measure the depth of the sea.
How is sea surface measured?
To measure SST, scientists deploy temperature sensors on satellites, buoys, ships, ocean reference stations, and through marine telemetry. The NOAA-led U.S. Integrated Ocean Observing System (IOOS®) and NOAA’s Center for Satellite Applications and Research (STAR) merge their data to provide SSTs worldwide.
What is swath in remote sensing?
As a satellite revolves around the Earth, the sensor “sees” a certain portion of the Earth’s surface. The area imaged on the surface, is referred to as the swath.
How do you observe wind?
The easiest way to observe true wind direction is by looking at the clouds. Typically if the clouds are coming from the north, then it’s a north wind. If they’re coming from the west, it’s a west wind, etc.
How is sea depth calculated?
The depth of the ocean is calculated by knowing how fast sound travels in the water (approximately 1,500 meters per second). This method of seafloor mapping is called echosounding. Echosounders can use different frequencies of sound to find out different things about the ocean.
How does QuikSCAT measure winds?
QuikSCAT measured winds in measurement swaths 1,800 km wide centered on the satellite ground track with no nadir gap, such as occurs with fan-beam scatterometers such as NSCAT. Because of its wide swath and lack of in-swath gaps, QuikSCAT was able to collect at least one vector wind measurement over 93% of the World’s Oceans each day.
How does QuikSCAT compare to NSCAT?
Because of its wide swath and lack of in-swath gaps, QuikSCAT was able to collect at least one vector wind measurement over 93% of the World’s Oceans each day. This improved significantly over the 77% coverage provided by NSCAT.
What is the QuikSCAT mission?
The QuikSCAT mission is a “quick recovery” mission to fill the gap created by the loss of data from NSCAT, after the satellite it was flying on lost power in June 1997. Winds play a major role in every aspect of weather on Earth.
What is the spatial resolution of the QuikSCAT measurements?
Standard processing of the QuikSCAT measurements yields a spatial resolution of about 25 km. A higher spatial resolution of 12.5 km is also achieved through special processing, but has significantly more measurement noise.