Jonathan Karr
Satellite
remote sensing of precipitation: progress and problems
Author: Barrett, Eric C.
Source:
Remote Sensing and Hydrology 2002 (IAHS Publication no. 267) 3-10
Editors: Owe, Manfred; Brubaker, Kaye; Ritche, Jerry; and Rango, Albert
Date: April 2000
Location: Barker Library GB651.I61 no.267
Notes
- Precipitation
is difficult to measure
- Never easy to determine
no-rain boundaries
- For global weather
forecasting purposes, raingauges are used, despite many problems with integrating
data from multiple guages
- Many times of
guages
- Different classes
of families of guages measure rain at different intervals
- Shapes and sizes
of guages vary
- Deficiencies
in rainfall station managment and data quality control are comm
- Real-time data
collection of rainfall may not be possible due to storm disruption of guages
- Radars are designed
to reveal continous pictures of the spatial distribution of rainfall better
than guage networks
- Provide data
for short-term forecasting
- Two types of
rainfall monitoring
- Three types
of electromagnetic radiation have proven valuable for the estimation of rainfall
- VIS (visual)
- Short-wave
radiation (sunlight) reflected back towards space from the tops of clouds
most with the .4-.7µm region of spectrum
- .5-2.5
µm spatial resolution
- Obtained
for high-ordibiting geostationary satellites (GEOs) and low-orbiting Earth
satellites (LEOs)
- IR (thermal)
- MW (microwave)
- poorest
spatial resolution
- Active
- First system
is the Japanese / US Tropical Rainforest Measuring Mission (TRMM) satellite
- System
also integrates precipitation radar (PR), passive microwave (PMW), VIS and
IR data
- Two altitude
levels
- GEOs
- Capable of
providing very frequent information from fixed positions in relation to the
Earth
- LEOs
- Problems
- Temporal, spatial,
and spectral characterisitcs of satellites need improvement to collect data
on a phenomenon as variable as rainfall
- Varied interactions
between electromagnetic radiation and environment
- Availability
of surface data for calibration
- Lack of systems
to evaluate data
- Orbit the
Earth many times / day
- Can provide
at best 2 two observations of any point on Earth
Trends in the hydrologic cycle of the Amazon basin
Authors: Costa, Marcos Heil adn Foley, Jonathan A.
Source: Journal of Geophysical Research V.104, D.12, P.14,189-14,198
Date: June 27, 1999
Location: Lindgren Library