The free CBERS-2 data access policy that has been adopted by the National Institute for Space Research (INPE) in Brazil and due differences in the image production (mainly DAPT secretase Notch in relative calibration) criteria adopted by the two countries Inhibitors,Modulators,Libraries (China and Brazil), encouraged Brazilian researchers and engineers to performed their own in-flight Inhibitors,Modulators,Libraries absolute calibration sellckchem campaigns [2, 3] and closely participate of pre-launch absolute calibration tasks performed in China.The objective of this paper is to describe the CCD/CBERS-2B pre-launch absolute calibration coefficients calculations based on data collected in the satellite integration and test hall located in China and relatively calibrated images generated in Brazil.2.
?CCD/CBERS-2B sensor short descriptionThe CCD/CBERS-2B sensor has the same technical characteristics of its predecessor ones onboard of CBERS-1 and CBERS-2 satellites.
It provides images with 113 Inhibitors,Modulators,Libraries km Inhibitors,Modulators,Libraries of swath with 20 m spatial resolution and also has a lateral pointing capability of �� 32��. It operates in 5 spectral bands such as: CCD1 (0.45 �C 0.52 ��m -blue); CCD2 (0.52 �C 0.59 ��m – green); CCD3 (0.63 �C 0.69 ��m – red); CCD4 (0.77 �C 0.89 ��m – near infrared) and CCD5 (0.51 �C 0.73 ��m �C panchromatic). A complete coverage cycle of the CCD camera takes 26 days.Figure 1 shows the actual spectral response of the CCD/CBERS-2B bands. These curves were originated from spectral measurements performed in laboratory taking into account the response per radiance Inhibitors,Modulators,Libraries unit.
In Figure 1 the data have been normalized (from 0 to 1) to facilitate relative comparison between bands.
Figure 1.CCD/CBERS-2B normalized spectral response.Basically Inhibitors,Modulators,Libraries the CCD/CBERS-2B is composed by four pieces of equipment: the Optical Mechanism, the Optical Mechanism Control Carfilzomib Box, the Thermal Controller and the Camera Electronics. In calibration terms, the most important Inhibitors,Modulators,Libraries equipments are the Optical Mechanism and the Camera Electronics. Here, emphasis will be dedicated to the Camera Electronics equipment. Basically, this equipment takes the CCD signal generated in each band and converts them into video output signals through Inhibitors,Modulators,Libraries two channels in which the gain control is made. According to this equipment conception, signals from bands 1, 3 and 5 pass through channel 1, while signals from bands 2, 3 (again) and 4 pass through channel 2.
The redundancy conception has also been applied at this equipment.
Thus it is possible generating video output signals considering ��main�� and ��redundant�� options that must be considered in the absolute selleck chem calibration coefficients calculations.The Brefeldin_A video output signals from the Camera Electronics equipment go toward an independent satellite sub-system called CCD_DT, in which there is equipment BIBF 1120 called Encoder that converts the video input signals into 8 bits digital data. The Encoder also runs with redundancy.