Beginning with the analysis on the principle of photoelectric sunshine duration sensor and combining with the problems occurred in use,various factors affecting the accuracy of observation are discussed. The digital s...Beginning with the analysis on the principle of photoelectric sunshine duration sensor and combining with the problems occurred in use,various factors affecting the accuracy of observation are discussed. The digital sunshine duration sensor solutions are put forward by analysis on the data detection and observation,the corrections on the error factors are discussed,such as directional response characteristic,stray light and temperature characteristic. As a consequence,the precision of the sunshine duration with automatic observation is improved.展开更多
A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant co...A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant colony algorithm to have the best compatibility with J2 invariant orbits created by differential correction algorithm. The configuration has succeeded in assigning the across-track baseline to vary periodically and with its mean value equal to the optimal baseline determined by the relative height measurement accuracy. The required relationship between crafts＇ magnitudes and phases is formulated for the general case of interferometry measure from non-orthographic and non-lateral view. The J2 invariant configurations created by differential correction algorithm are employed to investigate their compatibility with the required configuration. The colony algorithm is applied to search the optimal configuration holding the near-constant across-track baseline under the J2 perturbation, and the absolute height measurement accuracy is preferable as expected.展开更多
The article presents a new （1＋1）-bit/stage structure for pipelined analog-to-digital converters （ADC）. When the input analog signal of the structure exceeds the converting range of the whole ADC, the signal can s...The article presents a new （1＋1）-bit/stage structure for pipelined analog-to-digital converters （ADC）. When the input analog signal of the structure exceeds the converting range of the whole ADC, the signal can still be converted precisely and the output residue voltage of the structure will be in the converting range of the ADC. The structure is used in a 12-bit 40 MS/s pipelined ADC to test its function. The testing results show that the structure has right function and can correct the transition error induced by offset of comparators＇ decision levels. The ADC implemented in Semiconductor Manufactory International Corporation （SMIC） 0.18 μm CMOS process consumes 210 mW and occupies a chip area of 3.2×3.7 mm2.展开更多
文摘Beginning with the analysis on the principle of photoelectric sunshine duration sensor and combining with the problems occurred in use,various factors affecting the accuracy of observation are discussed. The digital sunshine duration sensor solutions are put forward by analysis on the data detection and observation,the corrections on the error factors are discussed,such as directional response characteristic,stray light and temperature characteristic. As a consequence,the precision of the sunshine duration with automatic observation is improved.
基金supported by the National Natural Science Foundation of China (10702003)
文摘A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant colony algorithm to have the best compatibility with J2 invariant orbits created by differential correction algorithm. The configuration has succeeded in assigning the across-track baseline to vary periodically and with its mean value equal to the optimal baseline determined by the relative height measurement accuracy. The required relationship between crafts＇ magnitudes and phases is formulated for the general case of interferometry measure from non-orthographic and non-lateral view. The J2 invariant configurations created by differential correction algorithm are employed to investigate their compatibility with the required configuration. The colony algorithm is applied to search the optimal configuration holding the near-constant across-track baseline under the J2 perturbation, and the absolute height measurement accuracy is preferable as expected.
基金supported by the Project of Applied Materials (XA-AM-200506).
文摘The article presents a new （1＋1）-bit/stage structure for pipelined analog-to-digital converters （ADC）. When the input analog signal of the structure exceeds the converting range of the whole ADC, the signal can still be converted precisely and the output residue voltage of the structure will be in the converting range of the ADC. The structure is used in a 12-bit 40 MS/s pipelined ADC to test its function. The testing results show that the structure has right function and can correct the transition error induced by offset of comparators＇ decision levels. The ADC implemented in Semiconductor Manufactory International Corporation （SMIC） 0.18 μm CMOS process consumes 210 mW and occupies a chip area of 3.2×3.7 mm2.
