# Presentation: 671118

## AMSR-E Data and Imagery

- _Outline_:
- Required knowledge base
- Orbit and scan characteristics
- Microwave channels
- Spatial resolution
- Usage and products
- References and links

**AMSR-E Data and Imagery**

## Required Knowledge Base

-  basic remote sensing concepts of reflected and emitted radiation
-  knowledge of the solar and terrestrial energy spectrum
-  have familiarity with GOES data for the detection and monitoring of the atmospheric processes, clouds, the land and ocean surfaces

**Required Knowledge Base**

## Aqua Orbital Characteristics

-    Aqua:	Launched May 4, 2002
- 	“afternoon” satellite
- 	1:30pm/am overpass
- 	AIRS, AMSU, HSB, AMSR-E, CERES, MODIS
-  16 orbits per day (~100min/ orbit)
-        for global coverage
-  area coverage 1-2 times per day
-        depending on latitude/sensor
-  lower orbit permits higher spatial
-         resolution measurements
-  orbital precession allows repeat of
-         exact orbit every 16 days

**Aqua Orbital Characteristics**

##  AMSR-E Products

_***Swath Point Data***_
- AE_L2B	Brightness Temperature
- AE_Rain	Rain Rate, Rain Type
- AE_Ocean	Sea Surface Temperature, Near-surface Wind Speed, Water Vapor (VI), Cloud Liquid Water (VI)
- AE_Land	Surface Soil Moisture, Vegetation Water Content, Surface Type
_***Daily Grids***_
- AE_DyOcn	Sea Surface Temperature, Near-surface Wind Speed, Water Vapor (VI), Cloud Liquid Water (VI)
- AE_Land3	Surface Soil Moisture, Vegetation Water Content, Surface Type
_***Weekly Grids***_
- AE_WkOcn	Sea Surface Temperature, Near-surface Wind Speed, Water Vapor (VI), Cloud Liquid Water (VI)
_***Monthly Grids***_
- AE_RnGd	Rain Accumulation
- AE_MoOcn	Sea Surface Temperature, Near-surface Wind Speed, Water Vapor (VI), Cloud Liquid Water (VI)
- (Snow and Sea-Ice Products are also available)			               VI – Vertically Integrated

##  AMSR-E Coverage

- An example of the AMSR-E daily coverage of the Earth is illustrated below.  Due to the precession of the Aqua orbit the data voids (gray diamonds) will shift in longitude so that all areas are covered at least once every 16 days.  In the southern U.S. the typical coverage is once or usually twice daily. This limited coverage is due to the relatively narrow swath width of 1445 km.

## AMSR-E Scan Characteristics

**AMSR-E Scan Characteristics**

- passive microwave scanning radiometer
- six frequencies at 6.9, 10.7, 18.7 23.8, 36.5, and 89.0 GHz
- each frequency has 2 channels
- conically scans through nadir at ± 61 degrees
- earth incidence angle of 55 degrees creates elliptical footprints
- surface swath width of 1445 km
- samples are 10 km apart (5 km at 89 GHz)

## AMSR-E TB’s

**AMSR-E TB’s**

- H-plane

- V-plane

##  AMSR-E Data

##  AMSR-E Data

- Note the following on the previous imagery of the TBs

- 6.9 GHz is contaminated with RFI (radio frequency interference); 10.7 GHz rarely so at this resolution.
- the higher the frequency, the higher the sensitivity to water vapor and ice crystals.
- the images are blurrier at the lower channels due to decreased resolution
- the microwave radiation from any given footprint reaching the AMSR-E is influenced by complex combinations of emission and scattering from all objects in the FOV.

| Frequency | Footprint Size | Mean Resolution |
| --- | --- | --- |
| 6.9 | 75 x 43 km | 56 km |
| 10.7 | 51 x 29 km | 38 km |
| 18.7 | 51 x 29 km | 21 km |
| 23.8 | 27 x 16 km | 21 km |
| 36.5 | 14 x 8 km | 12 km |
| 89.0 | 6 x 4 km | 5.4 km |

##  AMSR-E Product Specifications

- Rain Accumulation is a sum of the rain rate product for a given month to a predefined 5 x 5 degree global grid.  Snow products are also available and are in “EASE” projection (similar to Polar-Stereographic projection)

| Product | Base Resolution | Valid Range | Other Information |
| --- | --- | --- | --- |
| Rain Rate (liquid water) | 5.4 km | 0 – 50 mm/hr | restrained to a maximum of 50 mm/hr |
| Rain Type | 5.4 km | 0 – 100 percent | convective rain percentage |
| Sea Surface Temp 1 | 56 km | -3.0 – 34.5 C | based on 6.9 GHz, ~1 mm depth |
| Sea Surface Temp 2 | 38 km | -3.0 – 34.5 C | based on 10.7 GHz, ~1 mm depth |
| Wind Speed 1 | 38 km | 0 – 50 m s-1 | based on 10.7, 10m above surface |
| Wind Speed 2 | 21 km | 0 – 50 m s-1 | based on 18.7, 10m above surface |
| Water Vapor | 21 km | 0 – 75 mm | based on 18.7, vertically integrated |
| Cloud Liquid Water | 12 km | 0 – 2.5 mm | based on 36.5, vertically integrated |
| Soil Moisture | 56 km | 15 – 500 g cm-3 | based on 6.9 GHz |
| Vegetation Water Amt. | 56 km | 0 – 1000 kg m-2 | based on 6.9 GHz |
| Surface Topography | 56 km | 1 – 16  | utilizes USGS databases |

## AMSR-E Rain Rate Product

- 5.4 km resolution
- Data range is 0 – 50 mm/hr (25.4 mm = 1 in)
- instantaneous estimate, making it hard to quantify accuracy versus radar estimates and rain gage totals
- Reaches beyond the range of ground-based radar and does not suffer to attenuation

- NCEP Stage IV 1-hour total

- AMSR-E instantaneous rate

## AMSR-E Rain Rate Product

- Examples of AMSR-E advantages and disadvantages.

- NCEP Stage IV 1-hour total

- AMSR-E instantaneous rate

**Possible Attenuation / Averaging**

**VOID**

**Data Losses**

## AMSR-E Rain Type Product

- The AMSR-E Rain Type product is the estimate of what percent of the rain (if any) within each footprint is convective in nature or due to convection.
- Not at all							             Entirely
- Convective						             Convective
- 0%							             100%

## AMSR-E Rain Products

- Florida heavy rain event – May 4, 2005 – 1842 UTC overpass

- Instantaneous rain rate (mm/hr)

- Instantaneous rain type (convective %)

## AMSR-E Sea Surface Temperature Products

- The AMSR-E Sea Surface Temperature products retrieve the ocean skin temperature.  There is a version based on the 6.9 GHz frequency (56 km res.) and a version based on the 10.7 GHz frequency (38 km res.)  It is contaminated where the footprint contains anything other than a pure ocean surface; therefore, it is not valid if land, sea-ice, precipitation, and/or RFI is present in the footprint.

## AMSR-E Wind Speed Products

- The AMSR-E Wind Speed products retrieve the ocean wind speed based at 10 meters above the water surface.  There is a version based on the 10.7 GHz frequency (38 km res.) and a version based on the 18.7 GHz frequency (21 km res.)  It is contaminated where the footprint contains anything other than a pure ocean surface; therefore, it is not valid if land, sea-ice, precipitation, and/or RFI is present in the footprint.

## AMSR-E Atmospheric Products

- The AMSR-E Water Vapor and Cloud Liquid Water products retrieve the vertically integrated (columnar) atmosphere totals.  They are contaminated where the footprint contains anything other than a pure ocean surface; therefore, they are not valid if land or sea-ice is present (water vapor product not valid in heavy precipitation.)

## Additional Information

_**Web links**_**   **
**http://www.ghcc.msfc.nasa.gov/AMSR/****	****NASA AMSR-E homepage**
**http://nsidc.org/daac/amsre/****	****	****NASA EOS data source**
**http://sharaku.eorc.nasda.go.jp/AMSR/****	****JAXA (Japan) homepage**
**http://www.remss.com/                 ****	****	****alternate for ocean products**
_**Training modules (POWERPOINT)**_
** ****AMSR-E Data and Products (under development)**
_**VISITview modules**_
** ****AMSR-E Products in AWIPS (under development)**

**Additional Information**