SCIAMACHY (scanning imaging absorption spectrometer for atmospheric cartography) is a spectrometer with a wavelength range stretching from the UV (240 nm) to the NIR (2380 nm), addressing the trace gases important in the ozone cycle and the gases involved in global climate change. It is scheduled to fly on ESA's ENVISAT, launch 1998/99. In concept the instrument is similar to the recently launched instrument GOME on ERS-2, which is a scaled- down version of SCIAMACHY. For the UV and visible wavelengths the RL 1024 SR detector arrays of EG&G Reticon are employed, similar to those of GOME. For the detection of wavelengths beyond 1000 nm (not present in GOME) InGaAs is selected as detector material. Up to 1600 nm the lattice-matched In.53Ga.47As is used. For the longer wavelengths, strained-layer InxGa1-xAs, with x between 0.60 and 0.83, has been developed by Epitaxx Inc. (New Jersey). Emphasis during the development was on extending the sensitivity to longer wavelength, whilst keeping the dark current (noise) within acceptable levels. In this paper we present the design and the first performance results of the flight models for all InGaAs focal plane arrays (FPAs). Measurements of the spectral response, dark current and noise are presented, in combination with characteristics of the application-specific capacitive trans-impedance amplifier multiplexer. The performance data of the NIR FPAs have been incorporated in the SCIAMACHY-instrument simulator. As an example of its use, the predicted sensitivity to retrieve CO, N2O and CH4 abundances is given.