|
1
|
|
|
2
|
- Types of Satellite Imagery available on the NWS web pages.
- Strengths and weaknesses of different channels.
- Weather patterns and associated satellite image interpretation for
pre-flight self briefings.
|
|
3
|
- GOES Weather satellites in geosynchronous orbit.
- Imager (camera) on the satellite detects radiation returned from clouds
and the earth’s surface.
- Imager can detect and analyze different channels or “bandwidths” of
radiation and transform these measurements into various usable images.
- Multiple different images are available for the same time over any
particular location…each image offering certain advantages and
disadvantages in analyzing current weather systems.
|
|
4
|
|
|
5
|
|
|
6
|
- The resolution of the image is expressed in Kilometers (km).
- Resolution is the smallest object/area that can be resolved on the
image.
- Thus smaller resolution numbers (1km or 2 km) can resolve smaller
objects like individual Cu clouds better then larger resolution numbers.
- Paradoxically…these smaller resolution numbers are known as High
Resolution images.
- High resolution images generally focus on smaller regions.
|
|
7
|
|
|
8
|
|
|
9
|
- Senses and displays temperature in various color schemes.
- Colder surface temperatures are usually enhanced…thus high cloud tops
show up well.
- Commonly used on TV weather casts.
|
|
10
|
- Good overview of weather systems
- Animated loops provide clues as to strengthening or weakening of weather
systems.
|
|
11
|
- Very cold terrain will be enhanced where no clouds exist.
- High thin cirrus hard to distinguish from deep precipitation producing
clouds.
- Low clouds and fog do not show up very well.
|
|
12
|
|
|
13
|
|
|
14
|
|
|
15
|
|
|
16
|
- Displays water vapor field in the upper troposphere (usually above 20kft
).
- Areas of weak enhancement don’t always indicate clouds.
- Useful for locating jet streams.
- Can be used to infer cross mountain flow and possible mountain wave
turbulence.
|
|
17
|
|
|
18
|
|
|
19
|
- Use with IR image to separate thin Ci from deep precipitation producing
layers.
- Higher resolutions can discern subtle boundaries and fronts.
- Easier to detect low clouds and fog than with IR imagery (during
daytime).
- Good for detecting smoke and dust storms.
|
|
20
|
- Snow cover and fog/stratus similar appearance.
- Not useful if thick high clouds are present.
- Only available in daytime.
|
|
21
|
|
|
22
|
|
|
23
|
|
|
24
|
- Identifies low level fog and stratus day and night.
|
|
25
|
- Useful for separating fog and stratus from snow covered ground when used
with visible imagery.
- Available day and night.
- Will detect low clouds and fog which is too warm for IR imagery to
detect.
|
|
26
|
|
|
27
|
|
|
28
|
- Will not work very well when even thin higher clouds are present.
|
|
29
|
- Snow Cover versus Fog and Stratus
- Mountain Wave turbulence
- Thunderstorms
- Volcanic Eruptions
- Smoke and Dust
|
|
30
|
|
|
31
|
|
|
32
|
- Air being forced over high terrain.
|
|
33
|
|
|
34
|
|
|
35
|
|
|
36
|
|
|
37
|
|
|
38
|
|
|
39
|
|
|
40
|
|
|
41
|
|
|
42
|
|
|
43
|
|
|
44
|
|
|
45
|
|
|
46
|
|
|
47
|
|
|
48
|
- Visible satellite is generally the only useful channel for detecting
smoke.
- Usefulness is limited to daytime and generally clear skies.
- At night fires “lay down” and smoke is trapped under inversion near the
surface.
- During the day atmosphere mixes out inversion and smoke will plume.
|
|
49
|
|
|
50
|
|
|
51
|
|
|
52
|
|
Notes