In the past decades, hyperspectral imaging technologies was well developed in the whole world. Visible and Near Infrared hyperspectral imagers play an important role in agriculture, land use, forestry, etc. Higher performance airborne hyperspectral imagery is strongly expected these years. Wider Field of View and higher resolution instrument can acquire data more efficiently. A VNIR PHI with 40 degree FOV, 0.125mrad IFOV, 256bands was integrated last year. The system can adapt to the Velocity to Height Ratio lower than 0.04. The system consists of 3 subsystems. Every subsystem consists of TMA fore optics, spectrometer with planar blazed grating and electronics. The 3 subsystems work for left, middle, right FOV, respectively. Thanks to CCD’s pixel binning function, the system can operate in high spectral resolution mode, high spatial resolution mode, and high sensitivity mode for different applications. The integration was finished, and airborne flight validation experiments were conducted.
In order to solve the need for PC software of aerial imaging spectrometer USB3.0 high-speed large-capacity data acquisition system development. The project bases on MFC and DirectDraw technology by VS2010 development environment. The system can complete imaging spectrometer data acquisition , data storage and real-time imaging to monitor through the parsing of the spectral image data protocol. In addition, this paper also analyzes the factors that affect data acquisition bottleneck from computer architecture and software. The test results show that the PC acquisition platform can stabilize at 1.28 Gpbs data acquisition speed of some aerial imaging spectrometer requirements .It’s a new Light-weight and compact, low-cost and universal data acquisition approach for aerial imaging spectrometer.
As a key component of the hyperspectral imager, the use of high frame frequency CCD was more and more widely. CCD working principle was analyzed. Methods to realize high frame frequency and image programmable online were presented. Hardware driver design was designed. The image with high visibility, whose frame frequency was more than 320 Hz, noise was below 75e-, dynamic range was superior to 70dB, was acquired by the CCD. Based on the operating characteristic of the CCD, the temperature experiment was designed. Through the experiment, the relation curve of dark level and noise with the CCD detector temperature was given, which was helpful for the later image correction.
With the emergence of UAV (unmanned aerial vehicle) platform for aerial imaging spectrometer, research of aerial
imaging spectrometer DAS(data acquisition system) faces new challenges. Due to the limitation of platform and other
factors, the aerial imaging spectrometer DAS requires small-light, low-cost and universal. Traditional aerial imaging
spectrometer DAS system is expensive, bulky, non-universal and unsupported plug-and-play based on PCIe. So that has
been unable to meet promotion and application of the aerial imaging spectrometer.
In order to solve these problems, the new data acquisition scheme bases on USB3.0 interface.USB3.0 can provide
guarantee of small-light, low-cost and universal relying on the forward-looking technology advantage. USB3.0
transmission theory is up to 5Gbps.And the GPIF programming interface achieves 3.2Gbps of the effective theoretical
data bandwidth.USB3.0 can fully meet the needs of the aerial imaging spectrometer data transmission rate. The scheme
uses the slave FIFO asynchronous data transmission mode between FPGA and USB3014 interface chip. Firstly system
collects spectral data from TLK2711 of high-speed serial interface chip. Then FPGA receives data in DDR2 cache after
ping-pong data processing. Finally USB3014 interface chip transmits data via automatic-dma approach and uploads to
PC by USB3.0 cable.
During the manufacture of aerial imaging spectrometer, the DAS can achieve image acquisition, transmission, storage
and display. All functions can provide the necessary test detection for aerial imaging spectrometer. The test shows that
system performs stable and no data lose. Average transmission speed and storage speed of writing SSD can stabilize at
1.28Gbps. Consequently ,this data acquisition system can meet application requirements for aerial imaging spectrometer.