Airborne telesensing and satellite remote sensing were used
to gain its optical and radal remote sensing data
after Whenchuan earthquake, the spatial resolution reached 0.5m.
In some area, we used super–low altitude pilotless aircraft
to gain 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 can reflect various earthquakes,
which can apply to assess earthquake building damage,
research lifeline system of seismic hazard,monitore and evaluate secondary
earthquake disasters, for inquiring into the earthquake fault and
doing some emergency rescue.
The 10m spatial resolution can be used to monitore and evaluate
secondary earthquake disasters and look into the damaged road
to do some emergency rescue.
The weather and satellite revisit period have a big impact
on the remote sense image of E star, what's more,
it has many methods to obtain the information of disaster areas
and the methods are more effectively, and it has been widely used for measuring
earthquake deformation (especially co–seismic deformation ).
However, radar can't directly reflect
the condition in the same spatial resolution, so it need to be processed separately.
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 Wenchuan, the high resolution radar
at a level of meter is quite good for recognizing building damage.
The 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 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 at an ultra-low altitude. What's more, the image
that the aircraft obtained is very unambiguous and can most intuitively reflect
the disaster. 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 data.
The comparison among the pre–earthquake remote sense data,
the high resolution data and post–earthquake data will
contribute to enhance the mastery and efficiency
for disaster as well as provide a better emergency rescue.
We can establish the working system of emergency acquisition,
analysis processing and service, combined with remote sense data gained
by multiple ways. We can extremely support the emergency rescue
and alleviate maximum the losses caused by the earthquake.