After that, it discusses the principle of the band-pass technology, illuminating the feasibility of the digital intermediate frequency system based on the sampling speed which is two times lager than the signal band but unsatisfying the nyquist theorem 隨后討論了帶通采樣技術(shù)的原理,說明可以使用不滿足奈奎斯特低通采樣定理但大于信號帶寬兩倍的采樣速率進(jìn)行中頻數(shù)字化,減輕基帶處理負(fù)擔(dān)。
This dissertation aims at weak signal detection technology in micro-mechanical gyros, and digital correlated demodulation which can improve signal detecting accuracy is simulated; methods of compressing signal band width to improve signal-to-noise ratio and analyzing error production to decrease system error are researched 針對石英音叉微陀螺的微弱信號檢測技術(shù),本文通過仿真表明:利用數(shù)字相關(guān)解調(diào)方法提取陀螺信號可以很好地提高檢測精度。
Compared with traditional mechanical and optic gyros, hrg has such advantages as no high speed circumvolving or moving parts in structure, no warm-up time and short start-up time, wide signal band in frequency, low excursion noises, great endurance in over loading, nuclear radiation and short time power off, small bulk, light weight, low power cost and long life, which is suitable for space applications 與傳統(tǒng)的機(jī)械陀螺和光學(xué)陀螺相比,半球諧振陀螺具有如下優(yōu)勢:結(jié)構(gòu)上無高速轉(zhuǎn)子、無活動部件;不需預(yù)熱,啟動時間短;信號頻帶寬,漂移噪聲低;能承受大的機(jī)動過載;抗核輻射,并可經(jīng)受短時間電源中斷的影響;體積小,重量輕,功耗低,壽命長,非常適合空間應(yīng)用。
Because many image information data need to be transmitted and preserved, it is difficult to meet the requests for image information data to be transmitted and preserved by depending only on increasing the width of signal band and the processing speed of computers, we need to use image compression techniques to help to satisfy the requests 大量的圖像信息需要存儲和傳輸,僅依靠提高信道帶寬和計算機(jī)的處理速度,不能滿足人們對圖像信息存儲和傳輸?shù)男枰?,這就需要結(jié)合圖像的壓縮編碼技術(shù)來滿足人們的要求。當(dāng)前圖像壓縮技術(shù)在生物醫(yī)學(xué)應(yīng)用、無線通信、計算機(jī)圖形圖像處理等許多方面有著廣泛的應(yīng)用。