The mission images product shall serve the needs of
Taiwan government agencies first not only before and after the
crises but also during the crises especially when the local rain
rate can be significant for the disaster area. The team went
ahead to perform the payload operations simulation to
understand better the images taking performance in terms of
the link calculations for the terrain clutter targets imaging from
the 582-km orbit for both the descending and ascending
conditions. Antenna with 0.6 degree x 2 degree (azimuth vs.
range) beamwidths have been used for the simulation with the
four beam widths (in the range direction) all equal to 2 degrees.
Figures 2 and 3 below show the partial coverage capability of
the Taiwan island with these four beams. These beams can also
be used to form the ScanSAR mode when the suitable
electronic switching function performed. In either StripMap or
ScanSAR mode, there will be only one beam to be turned on
for the imaging function under the current payload power
management. Due to the 600-W peak output power selected
for our C-band system design and simulation, our HPA will
then consume 200~300 W (see Table III for its estimation basis)
in average while imaging Taiwan, then the imaging time
duration should not be limited for each pass once we have
enough power from the power supply of a modified
FORMOSAT-5 satellite bus (i.e., from 350 W to ~550 W in
average per orbit). Note that FORMOSAT-5 bus and its optical
payload will consume 270 W in average on orbit.