In almost Japanese megacities, various CO2 and CH4 emission source like industrial activity (power plant, landfills, gas factory, water processing plants), and agricultural activity (rice cultivation, pig farm) are concentrated within a few tens kilometers region. In order to estimate CO2 and CH4 emission rate for above various different sources, we newly developed airborne Imaging-spectrometer suites which consist of NIR spectrometer for O2-A band measurement and SWIR spectrometer for CO2/CH4 measurement. We also developed quick algorithm based on nonlinear fitting of synthetic spectrum to observation spectrum by optimization of column density of CO2 / CH4 and instrumental characteristic parameter simultaneously. The algorithm takes less than 20 second per 1 retrieval by using laptop computer, and we will challenge further acceleration by more than tens of times in order to realize real-time observation. For the first flight, we selected the eastern part of the Nagoya urban area, in which there are large CO2 emission sources, including a coal power plant and the transportation sector, and possible CH4 sources from agriculture, energy manufacturing, and waste that are geographically mixed. The results of observing the Hekinan power plant (coal-fired power generation) over Aichi Prefecture on Feb. 16, 2018 are shown in Figure 1. At the Hekinan Power Station, enhancement of CO2 column-averaged mole fractions are observed, and it can be seen that the high concentration area extends toward the downwind side. The accuracy of column density calculated by the quick algorithm will be validated with ground observation data. We estimated emission rate of CO2 of Hekinan Power plant.