Airborne telesensing and satellite remote sensing were used
after Whenchuan earthquate happened for gaining its optical
and radal remote sensing data, whose spatial resolution reached 0.5m.
In some area, we used super–low altitude pilotless aircraft
for a more distinct seismic image.
There are different degrees for satellite remote sensing images
due to the differences in the type of tracks, the style and number of sensors,
as well as the dissimilarity on revisit period, sway ability
and image spatial resolution, which leads to the diverse applications
in earthquake emergency, restoration and reconstruction, and research activity.
Spatial resolution of optical remote sensing image at a level of
general meter class(especially lm) and Ym is able to reflect various earthquake,
which can be applied to assess earthquake building damage,
research lifeline system of seismic hazard，monitore and evaluate secondary
earthquake disasters, inquire into the earthquake fault and
help to do some emergency rescue.
The 10m spatial resolution can be used to monitore and evaluate
secondary earthquake disasters, look into the damaged road
do some emergency rescue.
The weather and satellite revisit period can have a big impact
on the remote sense image of E star, while the satellite radar image
have little effect because of weather and the change of day and night,
what's more, it has many methods to get the information of disaster areas
and be more effectively, and has been widely used in the measuring of
earthquake deformation (especially co–seismic deformation ).
However, in the same spatial resolution, radar can't directly reflect
the condition of the disaster so clearly as optical image does that
it need to be processed exceptively. Therefore, radar remote sense
can be used in monitoring traffic damage and the big scales of
secondary earthquake disasters, such as hill–creep, debris flow，quake lake ect.
According to the practice case of Whenchuan, the high resolution radar
at a level of m (especially lm )and ym is quite good for recognizing building damage.
Data procurement by airborne optics and radar remote sense
had been tested in the earthquake site, Chinese Academy of Sciences,
the Bureau of Surveying and mapping，Ministry of land and resources State Bureau
of Surveying and Mapping and some other authorities were on the spot.
Compared with satellite remote sense, airborne remote sense
can get a clearer image, a higher comprehensive effectiveness for having images,
a better actual utilize of applying in earthquake emergency rescue,
and a lower effect by the weather. Nevertheless, the latter would deal with
plenty of datas as well as costing more money.
The portative unmanned aircraft is flexible, which is easy to shoot
by aerial means at an ultra-low altitude. What's more, the image
that the aircraft obtained is very unambiguous and can reflect
the disaster the most intuitively. Therefore, during the first fourteen days,
the photos taken from some distress areas played an important role in the implement
of emergency rescue work. Furthermore, the unmanned aircraft could also
handle a large amount of workload with the remote sense date obtained.
The comparison between the pre–earthquake remote sense date,
the high resolution date in particular, and post–earthquake data,
will contribute to enhancing the mastery and efficiency
for disaster as well as providing a better emergency rescue.
We can establish the working system of emergency acquisition,
analysis processing and service, combined with remote sense dates gained
by multiple ways. As we do so, we can extremely support the emergency rescue
and alleviate maximumly the losses caused by the earthquake.