監控系統分析

通(tong)(tong)常(chang)，一個(ge)標(biao)(biao)準的(de)(de)(de)視(shi)(shi)頻(pin)(pin)監(jian)控(kong)(kong)系(xi)統(tong)(tong)(tong)由五(wu)大部分組成(cheng)：視(shi)(shi)頻(pin)(pin)采集系(xi)統(tong)(tong)(tong)、視(shi)(shi)頻(pin)(pin)傳(chuan)輸(shu)(shu)(shu)(shu)系(xi)統(tong)(tong)(tong)、視(shi)(shi)頻(pin)(pin)切換管理(li)系(xi)統(tong)(tong)(tong)、視(shi)(shi)頻(pin)(pin)顯示系(xi)統(tong)(tong)(tong)和(he)視(shi)(shi)頻(pin)(pin)錄(lu)(lu)像(xiang)(xiang)系(xi)統(tong)(tong)(tong)。視(shi)(shi)頻(pin)(pin)采集系(xi)統(tong)(tong)(tong)主(zhu)要(yao)是(shi)完成(cheng)對(dui)(dui)前端(duan)圖像(xiang)(xiang)信號的(de)(de)(de)獲取；視(shi)(shi)頻(pin)(pin)傳(chuan)輸(shu)(shu)(shu)(shu)控(kong)(kong)制系(xi)統(tong)(tong)(tong)完成(cheng)對(dui)(dui)前端(duan)圖像(xiang)(xiang)信號的(de)(de)(de)傳(chuan)送和(he)控(kong)(kong)制通(tong)(tong)信；視(shi)(shi)頻(pin)(pin)切換管理(li)系(xi)統(tong)(tong)(tong)完成(cheng)對(dui)(dui)圖像(xiang)(xiang)信號的(de)(de)(de)切換控(kong)(kong)制和(he)資源分配；視(shi)(shi)頻(pin)(pin)顯示系(xi)統(tong)(tong)(tong)完成(cheng)對(dui)(dui)前端(duan)圖像(xiang)(xiang)信號的(de)(de)(de)終端(duan)設備輸(shu)(shu)(shu)(shu)出；視(shi)(shi)頻(pin)(pin)錄(lu)(lu)像(xiang)(xiang)系(xi)統(tong)(tong)(tong)完成(cheng)對(dui)(dui)前端(duan)圖像(xiang)(xiang)信號的(de)(de)(de)長延時存儲(chu)和(he)回放。在系(xi)統(tong)(tong)(tong)工程中(zhong)，良好(hao)(hao)的(de)(de)(de)視(shi)(shi)頻(pin)(pin)傳(chuan)輸(shu)(shu)(shu)(shu)設計(ji)是(shi)監(jian)控(kong)(kong)系(xi)統(tong)(tong)(tong)非(fei)常(chang)重(zhong)要(yao)的(de)(de)(de)一部分。如(ru)果建設一套(tao)好(hao)(hao)的(de)(de)(de)系(xi)統(tong)(tong)(tong)，選用的(de)(de)(de)攝像(xiang)(xiang)機(ji)、鏡(jing)頭(tou)、監(jian)視(shi)(shi)器、錄(lu)(lu)像(xiang)(xiang)機(ji)都是(shi)高指標(biao)(biao)、高籠-質的(de)(de)(de)，但是(shi)若沒有(you)良好(hao)(hao)的(de)(de)(de)傳(chuan)輸(shu)(shu)(shu)(shu)系(xi)統(tong)(tong)(tong)，最終在監(jian)視(shi)(shi)器上看到的(de)(de)(de)圖像(xiang)(xiang)將無法令人滿意。系(xi)統(tong)(tong)(tong)的(de)(de)(de)設計(ji)和(he)安裝(zhuang)人員(yuan)必須根據實際需要(yao)選擇合適的(de)(de)(de)傳(chuan)輸(shu)(shu)(shu)(shu)方式、高質量的(de)(de)(de)傳(chuan)輸(shu)(shu)(shu)(shu)介質、專用連接頭(tou)和(he)設備，并按(an)專業標(biao)(biao)準進行安裝(zhuang)，才能達到理(li)想的(de)(de)(de)傳(chuan)輸(shu)(shu)(shu)(shu)效果。

傳輸系統分析

目前，在安(an)防監(jian)(jian)控(kong)行業中的(de)前端攝像(xiang)(xiang)機(ji)(ji)有傳(chuan)(chuan)(chuan)統的(de)模擬攝像(xiang)(xiang)機(ji)(ji)和(he)(he)網(wang)絡(luo)攝像(xiang)(xiang)機(ji)(ji)兩種，但用(yong)來傳(chuan)(chuan)(chuan)輸圖像(xiang)(xiang)信號的(de)介質有很(hen)多，主要有是雙(shuang)絞(jiao)線(xian)、光纖和(he)(he)無(wu)(wu)線(xian)，對(dui)應(ying)的(de)傳(chuan)(chuan)(chuan)輸設(she)備分別是雙(shuang)絞(jiao)線(xian)視頻傳(chuan)(chuan)(chuan)輸設(she)備、光端機(ji)(ji)和(he)(he)無(wu)(wu)線(xian)網(wang)橋。下(xia)面就淺析(xi)一(yi)下(xia)目前監(jian)(jian)控(kong)系(xi)統使用(yong)最廣的(de)三種傳(chuan)(chuan)(chuan)輸介質的(de)性能優勢。

雙絞(jiao)線傳輸

雙(shuang)絞(jiao)線傳(chuan)輸(shu)最大(da)可以達到2400米(mi)，其價格便(bian)宜(yi)且接入方(fang)便(bian)，抗干擾能力也不(bu)錯(cuo)，采用(yong)PoE供電還(huan)可以減少綜合布線的任(ren)務量。但由(you)于(yu)(yu)雙(shuang)絞(jiao)線材(cai)質本身的限制(zhi)，它不(bu)抗老化(hua)(hua)，不(bu)能在條件(jian)比(bi)(bi)(bi)較惡劣的地(di)方(fang)傳(chuan)輸(shu)，如(ru)野外或(huo)者(zhe)化(hua)(hua)工廠等，并且它一次只能傳(chuan)輸(shu)一路圖像(xiang)，故不(bu)大(da)適合大(da)中型監控，同時傳(chuan)輸(shu)距離也有一定(ding)的限制(zhi)。雙(shuang)絞(jiao)線傳(chuan)輸(shu)比(bi)(bi)(bi)較適合用(yong)于(yu)(yu)中短(duan)距離、攝像(xiang)機點位(wei)相對(dui)比(bi)(bi)(bi)較分散不(bu)是(shi)很(hen)多(duo)或(huo)者(zhe)點位(wei)較近(jin)但比(bi)(bi)(bi)較集(ji)中的環境下的網(wang)絡(luo)攝像(xiang)機的視頻監控，如(ru)銀(yin)行、連鎖(suo)酒店、超(chao)市或(huo)者(zhe)大(da)學校(xiao)園(yuan)等。

光纖傳輸

采(cai)用(yong)光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)圖(tu)像(xiang)(xiang)信(xin)(xin)號(hao)(hao)是解決長(chang)距離(li)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)的最(zui)佳方(fang)式。光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)最(zui)遠可(ke)達到幾十甚(shen)至(zhi)一(yi)百(bai)多(duo)公里，它(ta)是通(tong)過把視(shi)頻(pin)(pin)(pin)(pin)及控(kong)制信(xin)(xin)號(hao)(hao)轉(zhuan)換為光(guang)(guang)(guang)(guang)(guang)信(xin)(xin)號(hao)(hao)在光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)中傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)，其(qi)優點(dian)(dian)是：傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)距離(li)遠、速率高(gao)、帶(dai)寬大(da)、衰減(jian)小、抗干擾性(xing)能(neng)最(zui)好，適合(he)(he)遠距離(li)和大(da)型視(shi)頻(pin)(pin)(pin)(pin)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)，如道(dao)路(lu)(lu)十字(zi)路(lu)(lu)口監(jian)控(kong)等(deng)。采(cai)用(yong)光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)的設備(bei)主(zhu)要為視(shi)頻(pin)(pin)(pin)(pin)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)與光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)收發(fa)(fa)器，視(shi)頻(pin)(pin)(pin)(pin)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)主(zhu)要應用(yong)在模擬(ni)攝像(xiang)(xiang)機(ji)的信(xin)(xin)號(hao)(hao)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)上，它(ta)信(xin)(xin)號(hao)(hao)損耗小，噪波與失(shi)真(zhen)小，傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)質(zhi)量高(gao)，適合(he)(he)遠距離(li)傳(chuan)(chuan)(chuan)(chuan)送。目(mu)前監(jian)控(kong)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)可(ke)以(yi)將(jiang)圖(tu)像(xiang)(xiang)、數據(ju)以(yi)及語(yu)音等(deng)信(xin)(xin)號(hao)(hao)無中繼傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)100公里，其(qi)次它(ta)抗干擾能(neng)力(li)強，對于雷擊(ji)、電磁(ci)輻射(she)它(ta)不(bu)受影響，這是同(tong)軸(zhou)電纜(lan)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)和雙絞線傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)所不(bu)具備(bei)的。傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)頻(pin)(pin)(pin)(pin)帶(dai)寬，理論可(ke)達30億(yi)兆赫，通(tong)訊容量大(da)，非(fei)常適合(he)(he)視(shi)頻(pin)(pin)(pin)(pin)信(xin)(xin)號(hao)(hao)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)。一(yi)個視(shi)頻(pin)(pin)(pin)(pin)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)可(ke)以(yi)同(tong)時(shi)接入多(duo)組模擬(ni)視(shi)頻(pin)(pin)(pin)(pin)信(xin)(xin)號(hao)(hao)，它(ta)適合(he)(he)多(duo)路(lu)(lu)復(fu)用(yong)的傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)，目(mu)前監(jian)控(kong)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)可(ke)實現在一(yi)芯光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)上同(tong)時(shi)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)128路(lu)(lu)實時(shi)非(fei)壓縮廣播(bo)級(ji)圖(tu)像(xiang)(xiang)，并且視(shi)頻(pin)(pin)(pin)(pin)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)不(bu)僅(jin)可(ke)以(yi)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)視(shi)頻(pin)(pin)(pin)(pin)信(xin)(xin)號(hao)(hao)，同(tong)時(shi)還(huan)可(ke)以(yi)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)音頻(pin)(pin)(pin)(pin)信(xin)(xin)號(hao)(hao)。光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)收發(fa)(fa)器適合(he)(he)網(wang)絡攝像(xiang)(xiang)機(ji)的信(xin)(xin)號(hao)(hao)傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)，同(tong)樣(yang)它(ta)也具有視(shi)頻(pin)(pin)(pin)(pin)光(guang)(guang)(guang)(guang)(guang)端(duan)(duan)機(ji)的傳(chuan)(chuan)(chuan)(chuan)輸(shu)(shu)(shu)(shu)(shu)(shu)(shu)距離(li)遠、損耗小、抗干擾能(neng)力(li)強等(deng)優點(dian)(dian)。