1378258 六、發明說明： 【發明所屬之技術領域】 本發明涉及衛星搜尋，尤其涉及動態且迅速地搜尋衛星的方法及實 施該方法的接收機。 【先前技術】1378258 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to satellite search, and more particularly to a method of dynamically and rapidly searching for a satellite and a receiver implementing the same. [Prior Art]
如今’多個全球導航衛星系統(Global Navigation Satellite System , GNSS)是可用的’包括美國的全球定位系統(GlobalPositioning System ’ GPS)具有32顆運轉衛星(〇perat；i〇nai satemtes)、歐洲的伽利略 具有27顆運轉衛星、俄羅斯的全球導航衛星系統(GL〇balNAvigati〇nToday, 'Global Navigation Satellite System (GNSS) is available', including the US Global Positioning System 'GPS' with 32 operating satellites (〇perat; i〇nai satemtes), Galileo in Europe Global navigation satellite system with 27 operational satellites, Russia (GL〇balNAvigati〇n
Satellite System，GLONASS)具有24顆運轉衛星、中國的北斗具有35 顆運轉衛星。由這些系統所構成的星系(c〇nstellati〇n)稱之爲超級GNSS 星糸。此外’區域導航衛星系統(Regi〇nalNavigation Satellite Systems， RNSS)也計劃在不久的將來運轉，例如日本的準天頂衛星系統 (Quasi-Zenith Satellite System，QZSS)以及印度的 GPS 輔助型靜地軌道 增強導航系統(GPS Aided Augmented Navigation System，GAGAN)。 % 此外’已開發各種星基增強系統(Satellite Based AugmentationSatellite System, GLONASS) has 24 operating satellites, and China's Beidou has 35 operating satellites. The galaxy (c〇nstellati〇n) formed by these systems is called the super GNSS star. In addition, the 'Regi〇nal Navigation Satellite Systems (RNSS) are also planned to operate in the near future, such as the Quasi-Zenith Satellite System (QZSS) in Japan and the GPS-assisted geostationary orbit enhanced navigation in India. System (GPS Aided Augmented Navigation System, GAGAN). % Also has developed various Satellite Based Augmentation Systems (Satellite Based Augmentation
Systems ’ SBAS)以增強GNSS，例如美國的廣域增強系統(wideArea Augmentation System，WAAS)、歐洲的同步衛星導航覆蓋服務 (European Geostationary Navigation Overlay Service，EGNOS)、曰本的 4 1378258 ， 度時，則該顆衛星視為可見。否則，該顆衛星視為不可見。然而，除 了衛星相對於接從機位置的仰角以外’每顆衛星的可見度亦可由其他 任何適當的方法決定。總而言之，衛星可見度可表示為接收機位置、 系統時間和衛星轨道資訊的一個函數。若接收機的粗略位置、粗略時 間和粗略衛星軌道資訊，例如六個刻卜勒轨道參數或衛星曆書 (almanac)是已知的，則在此條件下可得知哪顆衛星是可見的。其中粗 略時間可取自於接收機的即時時鐘(Real Time Clock，RTC)單元所提供 _的時間。相反地，若當前系統時間(如當前GPS時間)和衛星軌道資訊 是已知的，則可通過利用衛星是否可見來估計接收機位置。本發明即 基於此概念而發展。 在接下來的描述中，以具有32顆衛星(SV1，SV2,…，SV32)的GPS 為例。然而，本發明並不局限於此。 第1圖是根擄本發明顯示接收機1〇〇的方塊示意圖。接收機1〇〇 •接收和處理衛星信號(GPS信號或其他衛星系統信號)以定位接收機的 位置。例如，所有衛星的GPS信號由天線1〇1所接收，GPS信號為射 頻(^沁Frequency，RF)信號。射頻信號由前置放大器 放大。之後，利用頻率合成器114所提供的信號混合頻率，低向變頻 器(d〇wn-C〇nverter)116將放大的信號低向變頻至中頻(Intemiediate Frequency ’ IF)或基帶信號，其中頻率合成器114利用振盪器112提供 的參考時鐘生成所需鮮。中頻或基帶信號經由類比/數位轉換器 ianalGg_t〇_digitaU_ertei· ’ ADC)120轉換至數位信號。總體來說，前 1378258 •置放大器103、低向變頻器116、頻率合成器114、振盪器112及類比 /數位轉換器120被認為是一個整體’且作為射頻方塊11〇用於處理射 頻b號。之後’數位4§號傳送至關聯器130，以執行衛星代碼(如p咖 碼)與都卜勒頻移的關聯運算(correlation)以獲得關聯結果，以便鎖定衛 星代碼相位及都卜勒頻域的單位頻寬位置（D()pplerbin)。這就是所謂 的衛星搜哥。提供關聯器130的關聯結果至導航處理器14〇，以偵測 衛星的存在。導航處理器140控制關聯器no執行衛星搜尋(search)& 0 /或追蹤(tracking)。細節將進一步詳述於後。 在本實施例中，按每五度的經度和緯度對全世界的多個位置取樣， 因此將會有72 X 35 = 2520個可能位置，這些可能位置以{經度，緯度} 表示’例如{0, -85}，{〇, -80}，…，{0, 85}，..，{5, _85}，{5, _8〇}，，{5, 85}’…，{355,-85}，{355,-80}，…，{355, 85^然而，這些可能位置可經 由其他任何適當的方法所取樣。例如，可考量地球的幾何形狀，由此， 在尚緯度區域取樣的位置更少，在低緯度區域取樣的位置更多。在另 • 一情形中，僅有特定區域的位置包含在可能位置中。 . 第2圖是根據本發明的空間搜尋方法的流程圖。方法開始於步驟 S210。在步驟S220中，於導航處理器14()中設定一個包含Gps所有 32顆衛星的初始候選衛星列表「candList」。即初始candList= 〇,2，， 32}。在步驟S230中，於導航處理器14〇甲設定一個包含全世界位置 的初始可能位置列表「posList」。即 p〇sUst=H〇, _85}，{〇, _8〇}， ，{〇, 85}，…，{5, -85}，{5, -80}，…，{5, 85}，…，{355, -85}，{355, -80}，…， {355, 85}}。如上所述，這些可能位置可由其他方式設定。需注意步驟 8 1378258 .S220和S230的順序是任意的。這兩個步驟可平行執行。 在步靜S24〇卜計算每顆衛星在當前時間或特定時間於每個可能 位置的可見度「m(SV，p)」。如前所述，可見度從接收機位置、時間和 衛星軌道資訊中獲取。若特定衛星(如SV1)在特定位置(如pud 可見，則其可見度為1，即Vis(sv，p) = vis(svi，{〇，-85}) = ι。若衛星 svi在此位置不可見’則其可見度為G，即vis(sv，p) = ，价柳 =0 ° 參 在步驟S250 ’計算每顆衛星在所有可能位置的平均可見度 「meanVis(SV)」如下： 雜(1) 其中IposListl為posList中的位置數目；可以針對在候選衛星列表中 參的衛星或是所有可能的衛星(如GPS中的所有Μ顆可能的衛星:svi到 SV32)計算其平均可見度。 . 起初’在此例令，對於全世界的所有位置為每顆衛星SV1至SV32 .計算meanVis(SV)。也就是說，接收機可位於羅列位置中的任何位置。 第-次計算的結杲可贿現SV23的平均可見度是最細。即對於接 收機而言’.衛星SV23在當前系統時間是最可能可見的。因此，導航 處理器140選擇SV23作為要搜尋的候選衛星「candSV」(步驟S26〇)， 9 且指示關聯器130爲搜尋SV23執行關聯運算(步驟S270)，實行了此 搜尋的候選衛星（此處即衛星SV23)為一已搜尋衛星。在步驟S280 中，導航處理器M0決定SVM是否命中(hit)。若SV23命中(即獲得， 意謂該顆衛星可見），那麽SV23不可見的位置則從可能位置列表 P〇sList中移除。也就是說’導航處理器140從posList中移除每個 vis(candSV,p) = 〇的p(步驟S292)。若SV23未被命中(即未獲得，意謂 該顆衛星不可見）’那麼SV23可見的位置則從可能位置列表p〇sList 中移除。也就是說，導航處理器14〇從p0SList中移除每個Vis(candsv， p) = 1的p(步驟S295)。無論搜尋結果是什麼，可能位置的數量都會顯 著減少。也就是說，接收機的位置不確定範圍減小。需注意到應仔細 驗祖疋否發生衛星存在卻沒有被偵測到的情形(加沾detecti〇n)，以择保 未獲得的衛星確實是不可見的，同理，亦應確認已獲得的衛星確實是 可見的，使得不出現衛星存在卻宣稱未獲得和衛星不存在卻宣稱獲得 的情況。例如，在關聯器中使用較長的關聯積分時間(c〇ITdati〇n integration time)以達到信號的訊雜比(SNR) ’進而提高關聯器偵測衛星 的感度。或者，可以重複偵測同一顆衛星，以提高偵測機率(detecti〇n probability)和降低錯誤機率(faise aiarm)。 在步驟S300，導航處理器140決定是否已獲得預定數目的衛星。 若疋，過程可在步驟S310結束。否則，過程轉至步驟S32〇，更新候 選衛星列表candList。在本實施例中，一旦搜尋完一顆衛星，無論它 是否命中都從candList中移除。在另一個實施例中，一顆衛星只有在 被命中時才從candList中移除。更新candList後，在步驟S33〇中導航 盗4u決疋候選衛星列表咖犯对是否是空的。若候選衛星列表 :dL1St不是空的(即咖犯叫})，就意謂著當前這一輪的搜尋尚未 、，束。過程轉至步驟8250，導航處理器14〇使用減少的祕紐為 ^L1St中的每顆候選衛星計算平均可見度。在此實施例中，若候選 軒星歹J表candList疋空的(即candList =⑴，那麼在步驟幻奶導航處 =器⑽騎縣獅繼放嘯，叫τ—纖形成一個新 、初始候選衛星列表，且過程轉至步驟S25〇以運行下一輪搜尋。 “如下所給出的-個實驗性_子揭示了本發明柿於傳統方法的 效月b改進帛3圖至第π圖分別顯示了在此例的u次搜尋中的候選 衛星的可見位置的變化及平均可見度。在第3圖至第13圖的每個視圖 中’上方的圖表顯示了候選衛星的可見區域；下方的圖表顯示了每個 候選衛星的平均可見度。 s接收機關時，假設沒有任何義助資訊，騎有的32顆⑽ 籲?星都是候選衛星。也就是說候選衛星列表。祕如包含&顆⑽ 術星。接收機並不知道目前的位置Pq(J在特定當前時間（例如，删 時間），32顆GPS衛星中每顆衛星可見的位置記錄在第3圖上方的圖 表中。於此假設例中，在時間t〇衛星SV2、4、5、10、12、13、17及 6可見。如則所述’根據接收機的位置、衛星軌道資訊及Gps系統時 間，決定每顆衛星SV1至SV32的可見度vis(SV，p)為〇或！。對所有 位置計算32顆GPS衛星各自的平均可見度，結果顯示在第3圖下方 的圖表中。在此例中，在全世界内衛星SV23具有最大的平均可見度。 11 13/8258 因此，選擇SV23作為要搜尋的第一顆衛星β 如第3圖上方的圖表所示，虛線範圍(非陰影區)包含了 SV23可見 的位置，在特定位置pQ，衛星SV23不可見。因此，對SV23的搜尋 結果應為「未獲得」。基於SV23的搜尋結果，從可能位置中清除SV23 可見的位置。更新後的位置圖表如第4圖上方圖表所示。可以看到， 位置的不確定範圍顯著減少了。 如上所述’可能位置減少了。對剩餘的可能位置重新計算所有衛星 的平均可見度。結果如第4圖下方圖表所示。可以看到，衛星svi8 在此階段具有最大的平均可見度。因此，選擇§¥18作為要搜尋的第 二顆衛星。在上方圖表中，虛線範圍包含了 SV18可見的位置。 需注意到在此例中’無論是否命中，每顆衛星在一輪搜尋中僅能被 搜尋一次。因此，在第二輪搜尋中，SV23被從候選衛星列表中移除。 在特定位置P。衛星SV18不可見。因此，SV18的搜尋結果為「未 獲得」。SV18可見的位置則被消除。結果如第5圖上方的圖表所示。 可能位置進-步減知再次對剩餘的可能位置重新計算所有衛星的平 均可見度。結果如第5圖下方的圖表所示。由於州8已被搜尋過， 因此將其從候選衛星列表中移除。也就是說，再次更新候職星列表。 在該階段更新後的候選衛星列表中衛星SV17具有最大的可見度。因 此，選擇SVH作為要搜尋的第三顆衛星。在上方圖表中，虛=範圍 包含了 SV17可見的位置。 12 1378258 可以看到’在特定位置P〇衛星SV17是可見的。因此，對SV17的 搜尋結果為「命中」（即，獲得W肖除SV17不可見的位h結果如第 ^圖上方所示。可能位置進-步減知_餘的可能位置重新計 算所有衛星的平均可見度β結果如第6圖下方圖表所示。在本例中， 由於SV17已被搜尋過，因此將其從候選衛星列表中移除。也就是說， 再次更新候選魅職4此階段更概的親魅職巾衛星呢6 具有最大的可見度。因此，選擇SV26作為要搜尋的下一顆衛星。在 上方圖表中，虛線範圍包含了 SV26可見的位置。 「在特定位置PQ衛星SV26是可見的。因此，對奶6的搜尋結果為 「命中」（即’獲得）。消除SV26不可見的位置。結果如第7圖上方圖 表所不。可能位置進-步減少^對麵的可能位置重輯算所有衛星 的平均可見度i果如第7圖下方圖表所示。可以看到，除了已搜尋 過的衛星以外，衛星SV15具有最大的平均可見度。因此選擇⑽ 作為要搜尋的下-顆衛星。在上方誠中，虛線細包含了 可 見的位置。 「在特定位置P。衛星SV15是不可見的。因此，對SV15的搜尋結果 \未獲得」。消除SV15可見的位置。結果如第8圖上方圖表所示。 可此位置進-步減少。對剩餘的可能位置重新計算所有衛星的平均可 見度。結果如"圖下方圖表卿。可以看到，除了已搜尋過的衛星 以外，衛星SV13具有最大的平均可見度。因此選擇湘作為要搜尋 的下顆衛星。在上方圖表中，虛線範圍包含了 svi3可見的位置。 搜+過衛星SV13之後，重複上述過程以搜尋衛星SV4, SV10, SV2, SV12及SV5，相關圖表如第9圖至第13圖所示。 *在/ι次搜尋之後獲得所錢8顆衛星^14目左删表是每次搜 尋計算的每顆魅醉均可見度，蝴圖表為油的部分放大視 圖可以看到’在Π次的衛星搜尋中，衛星svi2和svi3的平均可 見度增加了。然而，衛星SV11和SV14的平均可見度減少了。 ▲當按本發_綠執行了較_紐尋後，若干麵星具有明顯 回的平均可見度(例如接近1；)，除了繼續執行本發明的方法，在此階段 也可順序搜尋這些被篩選的衛星。Systems ' SBAS ) to enhance GNSS, such as the United States' WideArea Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), and the transcript of 4 1378258 The satellite is considered visible. Otherwise, the satellite is considered invisible. However, the visibility of each satellite other than the elevation angle of the satellite relative to the slave position may be determined by any other suitable method. In summary, satellite visibility can be expressed as a function of receiver position, system time, and satellite orbit information. If the receiver's coarse position, coarse time and coarse satellite orbit information, such as six Buchler orbit parameters or satellite almanac, are known, then it is known which satellite is visible under this condition. The coarse time can be taken from the time provided by the receiver's Real Time Clock (RTC) unit. Conversely, if the current system time (e.g., current GPS time) and satellite orbit information are known, the receiver position can be estimated by utilizing whether the satellite is visible or not. The present invention has been developed based on this concept. In the following description, a GPS with 32 satellites (SV1, SV2, ..., SV32) is taken as an example. However, the invention is not limited thereto. Figure 1 is a block diagram showing the receiver 1A of the present invention. Receiver 1 • Receive and process satellite signals (GPS signals or other satellite system signals) to locate the receiver. For example, the GPS signals of all satellites are received by antenna 1〇1, and the GPS signals are radio frequency (RF) signals. The RF signal is amplified by the preamplifier. Thereafter, using the signal mixing frequency provided by the frequency synthesizer 114, the low-direction inverter (d〇wn-C〇nverter) 116 low-converts the amplified signal to an intermediate frequency (Intemiediate Frequency 'IF) or baseband signal, where the frequency Synthesizer 114 utilizes the reference clock provided by oscillator 112 to generate the desired fresh. The intermediate frequency or baseband signal is converted to a digital signal via an analog/digital converter ianalGg_t〇_digitaU_ertei·' ADC) 120. In general, the first 1378258 • the amplifier 103, the low-direction inverter 116, the frequency synthesizer 114, the oscillator 112, and the analog/digital converter 120 are considered to be one unit' and used as the radio frequency block 11 for processing the radio frequency b number. . The 'digit 4' number is then passed to the correlator 130 to perform correlation operations between the satellite code (eg, p-code) and the Doppler shift to obtain the correlation result to lock the satellite code phase and the Doppler frequency domain. The unit bandwidth position (D()pplerbin). This is the so-called satellite search brother. The correlation result of the correlator 130 is provided to the navigation processor 14A to detect the presence of the satellite. The navigation processor 140 controls the correlator no to perform satellite search & 0 / or tracking. Details will be further detailed below. In this embodiment, multiple locations around the world are sampled every five degrees of longitude and latitude, so there will be 72 X 35 = 2520 possible positions, which are represented by {longitude, latitude} 'eg {0 , -85},{〇, -80},...,{0, 85},..,{5, _85},{5, _8〇},,{5, 85}'...,{355,-85 }, {355, -80}, ..., {355, 85^ However, these possible locations may be sampled by any other suitable method. For example, the geometry of the Earth can be considered, whereby fewer locations are sampled in the latitude region and more at the lower latitudes. In another case, only the location of a particular area is included in the possible location. Figure 2 is a flow chart of a spatial search method in accordance with the present invention. The method begins in step S210. In step S220, an initial candidate satellite list "candList" including all 32 satellites of the Gps is set in the navigation processor 14(). That is, the initial candList= 〇, 2,, 32}. In step S230, the navigation processor 14 armor sets an initial possible position list "posList" containing the world position. That is, p〇sUst=H〇, _85}, {〇, _8〇}, , {〇, 85},...,{5, -85},{5, -80},...,{5, 85},... , {355, -85}, {355, -80},..., {355, 85}}. As mentioned above, these possible locations can be set in other ways. Note that step 8 1378258. The order of S220 and S230 is arbitrary. These two steps can be performed in parallel. In the step S24, the visibility "m(SV, p)" of each satellite at each possible position at the current time or at a specific time is calculated. As mentioned earlier, visibility is obtained from receiver position, time, and satellite orbit information. If a particular satellite (such as SV1) is in a specific location (such as pud visible, its visibility is 1, ie Vis(sv,p) = vis(svi,{〇,-85}) = ι. If satellite svi is not available at this location See 'The visibility is G, ie vis(sv,p) = , the price will be 0 °. In step S250 'calculate the average visibility of each satellite at all possible positions "meanVis(SV)" is as follows: Miscellaneous (1) Where IposListl is the number of positions in the posList; the average visibility can be calculated for the satellites participating in the list of candidate satellites or all possible satellites (such as all possible satellites in the GPS: svi to SV32). This example calculates meanVis (SV) for each satellite SV1 to SV32 for all locations in the world. That is, the receiver can be located anywhere in the listed position. The first calculated knot can be bribed SV23 The average visibility is the finest. That is, for the receiver, the satellite SV23 is most likely to be visible at the current system time. Therefore, the navigation processor 140 selects the SV23 as the candidate satellite "candSV" to be searched (step S26), 9 and instructing the correlator 130 to perform the associated operation for searching for the SV23 (Step S270), the candidate satellite (here, satellite SV23) that has performed the search is a searched satellite. In step S280, the navigation processor M0 determines whether the SVM hits. If the SV23 hits (ie, obtains, The satellite is visible, then the position where SV23 is not visible is removed from the possible location list P〇sList. That is to say 'the navigation processor 140 removes each vis from the posList (candSV, p) = 〇p (Step S292). If SV23 is not hit (ie, not obtained, meaning that the satellite is not visible) ' then the position where SV23 is visible is removed from the possible location list p〇sList. That is, the navigation processor 14〇 The p of each Vis (candsv, p) = 1 is removed from the p0SList (step S295). The number of possible positions is significantly reduced regardless of the search result. That is, the receiver's position uncertainty range is reduced. It should be noted that the situation in which the satellite is present but not detected (with detecti〇n) should be carefully examined to ensure that the satellites that are not obtained are indeed invisible. Similarly, it should be confirmed that they have been obtained. The satellite is indeed visible, so that no satellites appear However, it claims that it has not been obtained and the satellite does not exist but claims to be obtained. For example, using a longer associated integration time (c〇ITdati〇n integration time) in the correlator to achieve the signal's signal-to-noise ratio (SNR)' The correlator detects the sensitivity of the satellite, or it can repeatedly detect the same satellite to improve the detection probability and reduce the faise aiarm. At step S300, the navigation processor 140 determines whether a predetermined number of satellites have been obtained. If so, the process can end at step S310. Otherwise, the process proceeds to step S32, and the candidate satellite list candList is updated. In this embodiment, once a satellite is searched, it is removed from the candList whether or not it hits. In another embodiment, a satellite is removed from the candList only when it is hit. After updating the candList, in step S33, the navigation thief 4u decides whether the candidate satellite list guilty pair is empty. If the candidate satellite list: dL1St is not empty (ie, the coffee is called }), it means that the current round of search has not yet been, bundle. The process passes to step 8250 where the navigation processor 14 calculates the average visibility for each candidate satellite in ^L1St using the reduced secret. In this embodiment, if the candidate Xuan Xing J table candList is hollowed out (ie, candList = (1), then in the step of the magic milk navigation = device (10) riding the county lion to whistle, called τ - fiber to form a new, initial candidate The satellite list, and the process goes to step S25 to run the next round of search. "The experimental results given below show that the persimmon of the present invention is improved in the conventional method b 帛 3 to π respectively. The change in the visible position of the candidate satellite in the u-search in this example and the average visibility. In each of the views of Figures 3 to 13, the upper graph shows the visible area of the candidate satellite; the lower graph shows The average visibility of each candidate satellite. When receiving the organization, assuming that there is no information on the help, there are 32 (10) appealing satellites that are all candidate satellites. That is to say, the candidate satellite list. The secret contains the & The receiver does not know the current position Pq (J is at a specific current time (eg, deleted time), and the position visible for each satellite of the 32 GPS satellites is recorded in the graph above Figure 3. In this hypothetical example, At time t〇 satellite S V2, 4, 5, 10, 12, 13, 17, and 6 are visible. If the above is based on the position of the receiver, satellite orbit information, and Gps system time, determine the visibility vis of each satellite SV1 to SV32 (SV, p ) 〇 or !. Calculate the average visibility of each of the 32 GPS satellites for all locations, and the results are shown in the chart below Figure 3. In this example, satellite SV23 has the largest average visibility in the world. 11 13/ 8258 Therefore, select SV23 as the first satellite to be searched. As shown in the diagram above in Figure 3, the dotted line range (non-shaded area) contains the position where SV23 is visible. At a specific position pQ, satellite SV23 is not visible. The search result for SV23 should be “not obtained.” Based on the SV23 search results, the position visible to SV23 is cleared from the possible positions. The updated position chart is shown in the chart above in Figure 4. It can be seen that the position is uncertain. The range is significantly reduced. As mentioned above, the possible positions are reduced. The average visibility of all satellites is recalculated for the remaining possible positions. The result is shown in the chart below in Figure 4. It can be seen that the satellite svi8 is at this stage. The segment has the largest average visibility. Therefore, select §¥18 as the second satellite to be searched. In the upper chart, the dotted line contains the position where SV18 is visible. Note that in this case, 'whether or not hit, each The satellite can only be searched once in a round of search. Therefore, in the second round of search, the SV23 is removed from the list of candidate satellites. At a specific position P. The satellite SV18 is not visible. Therefore, the search result of SV18 is "not obtained. The position visible to SV18 is eliminated. The result is shown in the graph above Figure 5. Possible position-step reduction again recalculates the average visibility of all satellites for the remaining possible positions. The result is shown in the chart below Figure 5. Since State 8 has been searched, it has been removed from the list of candidate satellites. In other words, update the list of waiting stars again. The satellite SV17 has the greatest visibility in the updated list of candidate satellites at this stage. Therefore, SVH is selected as the third satellite to be searched. In the upper chart, the virtual = range contains the location where SV17 is visible. 12 1378258 It can be seen that 'P" satellite SV17 is visible at a specific location. Therefore, the search result for SV17 is "hit" (that is, the result of obtaining the bit h that is invisible to SV17 is shown in the figure above. The possible position is further reduced by the possible position of all satellites. The average visibility β result is shown in the chart below in Figure 6. In this example, since the SV17 has been searched, it is removed from the list of candidate satellites. That is, the candidate is updated again. The sneakers satellite 6 has the greatest visibility. Therefore, SV26 is selected as the next satellite to be searched. In the upper graph, the dotted line contains the position where the SV26 is visible. "The PQ satellite SV26 is visible at a specific location. Therefore, the search result for milk 6 is "hit" (ie 'acquisition". Eliminate the position where SV26 is not visible. The result is not shown in the chart above in Figure 7. Possible position step-by-step reduction ^ possible position re-calculation The average visibility of all satellites is shown in the chart below in Figure 7. It can be seen that satellite SV15 has the largest average visibility except for the satellites that have been searched. Therefore, (10) is selected as the search. Below - satellite. In the upper part, the dotted line contains the visible position. "At a specific position P. The satellite SV15 is invisible. Therefore, the search result for SV15 is not obtained." The position where SV15 is visible is eliminated. As shown in the chart at the top of Figure 8. This position can be reduced step by step. Recalculate the average visibility of all satellites for the remaining possible positions. The result is as shown in the chart below. You can see that in addition to the satellites that have been searched, Satellite SV13 has the largest average visibility. Therefore, choose Hunan as the next satellite to be searched. In the above chart, the dotted line contains the position visible in svi3. After searching + satellite SV13, repeat the above process to search for satellite SV4, SV10 , SV2, SV12 and SV5, related charts are shown in Figure 9 to Figure 13. * After the /ι search, get 8 satellites of the money ^14 left cut list is every charm calculated every search Visibility, the butterfly chart is a partial enlarged view of the oil. You can see that the average visibility of the satellites svi2 and svi3 has increased in the satellite search of the time. However, the average visibility of the satellites SV11 and SV14 is reduced. ▲When the _ green search is performed according to the present _ green, several face stars have obvious average visibility (for example, close to 1;), in addition to continuing to perform the method of the present invention, the sequels can also be searched sequentially at this stage. Screened satellites.
通過利用本發明的方法’動態的安排所要搜尋的候選衛星，在H 次搜尋中獲得所有的8顆衛星SV2、4、5、10、12、13、17及26。 相比來說，若利用傳統的順序搜尋方法，則需要26次搜尋才獲得8 顆衛星。 本發明可應麟-個更顧的情形(粗略的接收機位置和系統時間 均不可用）。在赠形下’我們可利用衛星搜尋結果估計接收機位置和 ^統時間。此處我們以GPS接收機為例。假設粗略的衛星軌道資料（如 衛星曆書）.是已知的，粗略的接收機位置和系統時間均未知。我們定 義衛星的平均可見度vls(SV，t，Lc，L)為隨時隨地看到衛星的可能性。 時空點（space-timepoint) P(t，Lc，L)指示在一特定系統時間和一特定 1378258 的點。然而，也可使用其他表達式來代 .地點（具有特定域和緯度) 表所述時空點。 第1^是_本發明的—種輕搜尋方法的流糊。在本實施例 ’ _五度的經度和緯度對全世界的多個位置取樣，因此將會有72 j 2520個可能位置，這些可能位置以{經度，緯度)表示，例如{〇, ；8sj>By using the method of the present invention to dynamically arrange the candidate satellites to be searched, all eight satellites SV2, 4, 5, 10, 12, 13, 17, and 26 are obtained in H searches. In comparison, if you use the traditional sequential search method, you need 26 searches to get 8 satellites. The present invention can be adapted to the situation (rough receiver position and system time are not available). Under the gift form, we can use the satellite search results to estimate the receiver position and time. Here we take the GPS receiver as an example. It is assumed that coarse satellite orbit data (such as satellite almanac) is known, and the rough receiver position and system time are unknown. We define the satellite's average visibility vls(SV,t,Lc,L) as the possibility to see the satellite anytime, anywhere. The space-time point P(t, Lc, L) indicates a point at a particular system time and a particular 1378258. However, other expressions can also be used to represent the space-time points described in the table (with specific domains and latitudes). The first is a paste of the light search method of the present invention. In the present embodiment, the longitude and latitude of five degrees are sampled at a plurality of locations around the world, so there will be 72 j 2520 possible positions, which are represented by {longitude, latitude, for example {〇, ;8sj>
Λ _ ' }，...，（355,85}。此外’由於GPS衛星在地面的軌跡週 ’〜24小時’因此本實酬巾獅％小時醜料職。對μ =的時間段(即議秒)每_秒取樣—次，因此共有ΐ44個時間 取樣。 —方法開始於步驟咖。在步驟咖中，於導航處理器14〇中設 疋包含哪所有32顆衛星的一個初始候選衛星列表「咖㈣」。即 初始candL· {1，2,…，32}。在步驟s咖中，於導航處理器⑽中 #設定包含全世界位置的一個初始可能的點列表「_〜其中聊 = 〇，_，…，_0;Lc (緯度卜85，_80,，85;及[(經度)=〇 5 曰 3…如上所述’這些可能_可由魏方式設心纽意步驟幻汹 和S1530的順序是任意的。這兩個步驟可平行執行。 點卩=(1：，1^1〇計算每顆 在步驟S1540中，為userST中的每個時空 衛星的可見度「vis(SV，P)」。 在步驟仍50’計算每麵星在所有可能位置的平均可見度 15 (2) 1378258 meanVis(SV)」如下： 其中丨userSTI為userST中的時空點的數目；可 表中的衛星或是所有可能的衛星(如GPS中的所有 SV1到SV32)計算其平均可見度。 此的衛星. 起初’在此例中，計算每顆衛星SV1至咖在所有點的平均可見 度meanV1S(SV)。也就是說，接收機可位於羅列點中的任何點。在牛 驟S測，導航處理器14〇選擇具有最大平均可見度的衛星作為要搜 尋的候選衛星「CandSVj (步驟_)，且指示關聯器13〇爲搜尋該 候選衛星candSV執行關聯運算(步驟sl57〇)。在步驟觀〇中，導航 處理器U0決定candSV是否命中。若candsv命中⑼獲得，意謂該 顆衛星可見）’職1SV不可見_職可能_職爾st^ 除。也就是說，導航處理器MO從讎ST中移除每個vis(candsv，p卜 〇的P(步騾S·)。若candSV未被命中(即未獲得，意謂該顆衛星不 可見）’那麼candSV可見的點則從可能的點列表咖阶中移除。也就 是說，導航處理器140從userST中移除每個vis(candsv，p)=〗的p(步 驟S1S95)。需注意到應仔細驗證是否發生衛星存在卻沒有被伽到的 情形(miss detection)，以確保未獲得的衛星確實是不可見的，同理’亦 應確認已獲得的錢確實是可見的’使得;^贿星存在卻宣稱未獲 得和衛星不存在卻宣稱獲得的情況。無論搜尋結果是什麽，可能的時 丄378258 二點的數a都會顯著減少。也就是說，接收機的時空不確定棚減小。 —在步驟S1600 ’導航處理$ 14〇決定是否已獲得預定數目的衛星。 右I過程可在步驟S161G結束。频，過轉至步驟S162G，更新 星職eandList。如社述實施例，—旦搜料-麟星，無 論它是否命巾都從eandList巾移除。在另_個實施射，—麟星只 有在被命巾時才從eandLi种移除。更新娜紐後，在步驟幻㈣ 中導般處理II 14G決定候職星絲·^是妓帥4候選衛 星列表candLlst不是空的(即candLi叫})，就意謂著當前這一輪的搜 ^尚未結束。過_至步驟S155Q，導航處理^⑽使用減少的窗灯 為:dUst中的每顆候選衛星計算平均可見度。在此實施例中若候 老、早丁星歹J表candList疋空的(即candList =⑴，那麼在步驟$獅導航 =理器140將所有未獲得的衛星放入列表以爲下一輪搜尋形成一個 的初始候選衛星列表，且過程轉至步驟sl55〇以運行下一輪搜尋。 第16圖為傳統的順序搜尋方法所獲得的結果與根據本發明的方法 ^獲得的結果之間的搜尋時間的比較圖。垂直軸為命中第κ個可見衛 的時間’水平軸為命中衛星的數目。若利用傳統的順序搜尋方法， ^需要26次搜尋才_顆衛星。如前所述，_本發明的空間搜尋 方法可在η:域料命中8顆魅。_本魏 :::rr8^ 2、摘連、·.避方法，需㈣次搜尋才能命中四顆魅^利用本發 月的工間搜尋方法，最初的四顆_可在7次搜尋中命中^利用本發 17 月的時工搜尋方法’最初的四顆衛星可在6次搜尋t命t。同時，使 用越夕顆衛星參財位可以改進接收機定辨確度減魏叙速度。 由於很多地找到所有可見的衛星，所以其達到高準續定位的速度遠大 於傳統方法。 ，上述之實施例僅用來例舉本發明之實施態樣，以及闊釋本發明之技 術特徵’並_來聞本發明之射。任何習知技藝者可依據本發明 泰之精神輕易完成之改變或均等性之安排均屬於本發明所主張之範圍， 本發明之翻範g應以帽專利範圍為準。 【圖式簡單說明】 第1圖是根據本發明顯示接收機的方塊示意圖。 第2圖是根據本發明的空間搜尋方法的流程圖。 第3圖至第13圖分別顯示了在此例的u次搜尋中的候選衛星的平 •均可見度及可能位置的變化。 第Μ圖左麵表是每次搜尋計算的每職星的平均可見度，右側 圖表為左侧圖表的部分放大視圖。 第15圖是根據本發明的一種時空搜尋方法的流程圖。 第16圖為佩_序搜尋方法峨得的結果與轉本發明的方法 所獲得的結果之間的搜尋時間的比較圖。 、 【主要元件符號說明】 1378258 100接收機 114 101 天線 116 103前置放大器 120 110射頻方塊 130 112振盪器 140 S210〜S340、S1510〜S1640 步驟 頻率合成器 低向變頻器 類比/數位轉換器 關聯器 導航處理器Λ _ ' },...,(355,85}. Also 'because of the GPS satellite's trajectory in the ground week~24 hours' therefore the actual reward lion lion% hour ugly job. For the μ = time period (ie Sampling every _ second, so there are a total of 44 time samples. - The method starts with the step coffee. In the step coffee, a list of initial candidate satellites containing all 32 satellites is set in the navigation processor 14A. "Caf (four)". That is, the initial candL· {1, 2, ..., 32}. In the step s coffee, in the navigation processor (10) # set an initial possible point list containing the world location "_~ where chat = 〇, _,...,_0;Lc (latitude 85,_80,,85; and [(longitude)=〇5 曰3... As mentioned above] these may be _ can be set by the Wei method, the steps of the illusion and the S1530 The order is arbitrary. These two steps can be performed in parallel. Point = (1:, 1^1〇 calculates the visibility "vis(SV, P)" of each space-time satellite in userST in step S1540. In the step still 50' calculate the average visibility of each star at all possible positions 15 (2) 1378258 meanVis(SV)" as follows: where 丨userSTI is us The number of spatiotemporal points in erST; the satellites in the table or all possible satellites (such as all SV1 to SV32 in GPS) calculate their average visibility. This satellite. Initially 'in this case, calculate each satellite SV1 The average visibility of the coffee at all points is meanV1S (SV). That is, the receiver can be located at any point in the list of points. In the case of the test, the navigation processor 14 selects the satellite with the largest average visibility as the search. The candidate satellite "CandSVj (step_), and instructs the correlator 13 to perform an association operation for searching for the candidate satellite candSV (step sl57). In the step view, the navigation processor U0 determines whether the candSV hits. If the candsv hit (9) is obtained , meaning that the satellite is visible) 'Occupation 1SV is not visible _ job possible _ er er st ^ divide. That is, the navigation processor MO removes each vis from the 雠ST (candsv, p 〇 P (step骡S·). If the candSV is not hit (ie not obtained, meaning the satellite is not visible)' then the point visible to the candSV is removed from the possible list of points. That is, the navigation processor 140 Remove each vis(candsv,p)= in userST p (step S1S95). It should be noted that it should be carefully verified whether satellites are present but not detected (miss detection) to ensure that the satellites that are not obtained are indeed invisible, and the same reason should be confirmed The money is indeed visible 'causes; ^ the existence of a bribe star claims that it has not been acquired and the satellite does not exist but claims to be obtained. No matter what the search result is, the number a of 378258 may be significantly reduced. That is to say, the time and space uncertainty of the receiver is reduced. - At step S1600' navigation processing $14, a decision is made as to whether a predetermined number of satellites have been obtained. The right I process may end at step S161G. Frequency, go to step S162G to update the star job eandList. As described in the example of the Society, the search for the Lin Xing, whether it is a life towel or not, is removed from the eandList towel. In another implementation, Lin Star was only removed from the eandLi species when it was killed. After updating Nana, in the step magic (four), the general treatment of II 14G decided to wait for the star silk · ^ is the handsome 4 candidate satellite list candLlst is not empty (ie candLi called }), it means the current round of search ^ Not yet finished. After _ to step S155Q, the navigation process ^(10) uses the reduced window light to calculate the average visibility for each candidate satellite in dUst. In this embodiment, if the old, early, and singular J table candList is empty (ie, candList = (1), then in the step $ lion navigation = processor 140 puts all the unobtained satellites into the list to form a search for the next round. The initial candidate satellite list, and the process goes to step sl55 to run the next round of searching. Figure 16 is a comparison of the search time between the results obtained by the conventional sequential search method and the results obtained by the method according to the present invention. The vertical axis is the time to hit the κth visible guard. The horizontal axis is the number of hit satellites. If the traditional sequential search method is used, ^26 searches are required for _ satellites. As mentioned above, the space search of the present invention The method can hit 8 charms in the η: domain material. _ Ben Wei:::rr8^ 2, picking up, ·. avoiding the method, need (4) search to hit the four charms ^ use this month's work search method, The first four _ can be hit in 7 searches. ^Using the current time of the search method of the month of 'the first four satellites can search for t life in 6 times. At the same time, the use of the date of the satellites can improve. The receiver determines the accuracy and reduces the speed of the Wei Xuan. Many visible satellites are found, so the speed of achieving high-order continuous positioning is much higher than the conventional method. The above embodiments are only used to exemplify the embodiments of the present invention, and broadly release the technical features of the present invention. The invention is not limited to the scope of the invention as claimed in the present invention. Any modification of the present invention is subject to the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a display receiver according to the present invention. Fig. 2 is a flow chart showing a spatial search method according to the present invention. Figs. 3 to 13 respectively show the example in this example. The average visibility and possible position changes of the candidate satellites in the secondary search. The left side of the figure is the average visibility of each star calculated for each search, and the right chart is a partial enlarged view of the left chart. Is a flow chart of a space-time search method according to the present invention. Figure 16 is a comparison of the search time between the result obtained by the Pei-sequence search method and the result obtained by the method of the present invention. Fig., [Major component symbol description] 1378258 100 receiver 114 101 antenna 116 103 preamplifier 120 110 radio frequency block 130 112 oscillator 140 S210~S340, S1510~S1640 step frequency synthesizer low-direction inverter analog/digital converter Correlator navigation processor
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