High Resolution 1:10,000 scale Mapping Strategy of Multi ... - NDMA

One current state-of–the-art direct georeferencing system uses GPS measurements
integrated with an Inertial Measurement Unit (IMU) and flight assistance technology
to measure sensor position and orientation up to 300 times per second. Whereas a
GPS can refresh position and orientation data accurately approximately once every
second if given direct line of sight to a minimum of 5 GPS satellites, a quality IMU
(supported by the GPS system) can fill in the GPS data gaps, performing even in the
absence of a suitable number of GPS satellite connections, during long outages, and
throughout tight turning maneuvers. (For more details please refer to Annex. VIII)
Software post-processing of collected data turns sub-meter accuracy into centimeter
accuracy by comparing position and orientation information before and after data
capture and filtering out anomalies. Integrating navigation data with airborne remote
sensing data means that exterior orientation parameters can be produced in near
real-time. Images are corrected without accepting the time cost, financial cost, or
possible dangers of collecting GCPs.
Suddenly, the most significant delay in getting data to response teams becomes the
wait for the plane to return !
Rapid response camera systems have benefited just as much from medium format
airborne digital camera advances over the past five years as they have from overall
system cost savings., Innovations in medium format lens quality, Pixel sizes, CCD
quantum efficiency, and radiometric performance have blurred long established
divisions between medium and large format aerial camera systems.
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