Ge?gr??h?c?l ?nf?rm?t??n system

?ntr?duct??n

G??gr??h?c?l ?nf?rm?t??n ?y?t?m? (G??) ?r? d???gn?d t? ?t?r?, r?tr??v?, m?n??ul?t?, ?n?lyz?, ?nd m?? g??gr??h?c?l d?t?. Th? c?ntr?l ?l?m?nt ?f ? G?? ?? th? u?? ?f ? l?c?t??n r?f?r?nc?ng ?y?t?m ?? th?t d?t? ?b?ut ? ???c?f?c l?c?t??n c?n b? ?n?lyz?d ?n ?t? r?l?t??n?h?? t? ?th?r l?c?t??n?. B?th ?l?n? ?nd gl?b?l c??rd?n?t? ?y?t?m? ?r? c?mm?nly u??d. ? ?y?t?m m?y b? c???bl? ?f ????ly tr?n?f?rm?ng ?n? r?f?r?nc?ng ?y?t?m (?.g. Un?v?r??l Tr?nv?r?? M?rc?t?r (UTM)) t? ??m? ?th?r r?f?r?nc?ng ?y?t?m (?.g. ?t?t? ?l?n? C??rd?n?t??). Th?? m?k?? ?t ?????bl? t? t?k? d?t? th?t h?? b??n ?t?r?d ?n ?n? f?rm ?nd c?mb?n? ?t w?th d?t? th?t h?? b??n ?nt?r?d ?nd ?t?r?d ?n ??m? ?th?r f?rm. Th? u?? ?f G?? h?? c?m? ?f ?g? ?? ? r??ult ?f ??v?r?l ?nt?rr?l?t?d f?ct?r?. F?r?t, th?r? ?r? m?ny G?? ??ftw?r? ?r?duct? th?t ?r? ?v??l?bl? fr?m c?mm?rc??l v?nd?r? ?nd un?v?r??t???. ??c?nd, c?m?ut?r w?rk?t?t??n? ?r? n?w c???bl? ?f h?ndl?ng m?ny ?f th? c?m?ut?t??n?l, r?tr??v?l, ?nd ?t?r?g? ?r?bl?m? w?th?n ? r????n?bl? ?m?unt ?f t?m? ?nd ?t r????n?bl? c??t. Th?rd, gr??h?c?l d???l?y? ?nd ?l?tt?r? ?r? n?w ???h??t?c?t?d ?nd f??t, ?r?duc?ng h?gh-qu?l?ty ?nd h?gh-r???lut??n ?ut?ut. F?urth, g??gr??h?c d?t? v?nd?r? ?? w?ll ?? g?v?rnm?nt?l ?g?nc??? ?uch ?? th? Bur??u ?f th? C?n?u? ?f th? U? G?v?rnm?nt h?v? m?d? l?rg? ?m?unt? ?f g??gr??h?c d?t? ?v??l?bl? ?t r????n?bl? c??t. F?fth, th? u?? ?f r?m?t? ??n??ng h?? ?x??nd?d, ????c??lly ?n ?nv?r?nm?nt?l m?n?t?r?ng, ?nd th?? h?? l?d t? th? n??d f?r ?y?t?m? th?t ?r? c???bl? ?f h?ndl?ng l?rg? ?m?unt? ?f d?t? ?? w?ll ?? ??rv? ?? ? m?j?r ??urc? ?f l?nd c?v?r?g? ?nf?rm?t??n. ??xth, th? ?m?rg?nc? ?f th? ??t?ll?t? b???d Gl?b?l ????t??n?ng ?y?t?m (G??) h?? m?d? ?t ???y t? c?ll?ct ?ttr?but? d?t? ?l?ng w?th ?t? l?c?t??n ?t r?l?t?v?ly l?w c??t ?nd w?th r?l?t?v?ly h?gh ?ccur?cy. ??ch ?f th??? f?ct?r? h?? c?ntr?but?d t? th? gr?wth ?f th? G?? ?ndu?try.

B?ckgr?und

Th?r? ?r? tw? fund?m?nt?lly d?ff?r?nt ty??? ?f G?? ??ftw?r?. Th?y d?ff?r ?n t?rm? ?f th? d?t? m?d?l, ?.?., th? m??n? f?r ?t?r?ng g??gr??h?c?l d?t?. ??nc? th? r??l w?rld ?? ?? c?m?l?x, ?t w?uld t?k? ?n ?nf?n?t?ly l?rg? d?t?b??? t? c??tur? th? r??l w?rld ?r?c???ly. D?t? th?r?f?r? mu?t b? g?n?r?l?z?d ?r ?b?tr?ct?d t? r?duc? ?t t? ??m? m?n?g??bl? qu?nt?ty. D?t? ?r? r??r???nt?d ?? ? f?n?t? ??t ?f ?bj?ct?. Th? tw? ?r?nc???l d?t? m?d?l? ?r? r??t?r ?nd v?ct?r. Th? r??t?r m?d?l d?v?d?? th? ?tudy ?r?? ?nt? ? r?gul?r gr?d ?f c?ll?, ??ch c?ll c?nt??n? ? ??ngl? v?lu?. ?n? ??t ?f c?ll? ?nd ????c??t?d v?lu?? ?? ? l?y?r ?nd ? d?t?b??? ty??c?lly c?nt??n? m?ny l?y?r? (?.g., l?nd c?v?r, ?l?v?t??n, ???l ty??, ?tc.).

Th? u?? ?f ?n? d?t? ?tructur? ?n?t??d ?f ?n?th?r ?? b???d u??n ? numb?r ?f f?ct?r?: (1) th? f?rm ?n wh?ch th? d?t? ?r? c?ll?ct?d ?r ?urch???d; (2) th? ty?? ?f ?n?ly??? ?nd m?d?l? f?r wh?ch th? d?t? m?y b? ???l??d; (3) th? c??t ?f th? G?? ?y?t?m ?nd d?t? ?ntry; (4) th? ty?? ?f ?qu??m?nt th?t m?y b? n??d?d t? ?u???rt th? ??ftw?r?; ?nd (5) th? ty?? ?f ??r??nn?l r?qu?r?d t? m?n?g? th? ?y?t?m. R??t?r ?y?t?m? t?nd t? c??t l??? ?nd b? d???gn?d t? ?ddr??? ?nv?r?nm?nt ?r?bl?m?. ?l?? ??m? m?d?l?, l?k? f?r? ??r??d m?d?l?, ?r? d???gn?d t? ???r?t? ?n c?njunct??n w?th ? r??t?r ?y?t?m. Unf?rtun?t?ly, ?uch ?y?t?m? c?nn?t r??r???nt ?tr??t n?tw?rk? ?ccur?t?ly. V?ct?r ?y?t?m? ?r? c???bl? ?f ?ccur?t?ly r??r???nt?ng ?tr??t n?tw?rk?, ?r???rty l?n??, ?nd l?nd u?? ??tt?rn? ?? w?ll ?? ?nv?r?nm?nt?l d?t?. Th? ??l?ct??n ?f ? ???c?f?c G?? ?y?t?m f?r ?n ?g?ncy ?r ?r?v?t? c?m??ny m?ght b? ? d?t??l?d ?nd c?m?l?c?t?d t??k. Th? c??t? t? ?wn, ???r?t?, ?nd m??nt??n ? G?? c?n b? ?ub?t?nt??l. M?ny G?? d???rtm?nt? ?nv?lv? num?r?u? ??r??nn?l. C?t???, f?r ?x?m?l?, t?nd t? d??tr?but? th? c??t? ?f ?uch ?y?t?m? ?m?ng ? numb?r ?f ??rv?c??, ?nclud?ng f?r? ?nd ??l?c?, urb?n ?l?nn?ng, tr?n???rt?t??n ?ng?n??r?ng, tr?n??t ?g?nc???, ??rk? ?nd r?cr??t??n, ?tc. Ju?t?fy?ng th? u?? ?f ? G?? ?? ?????r wh?n d?t? c?n b? ?h?r?d f?r ? numb?r ?f ?ur?????.

Br??f h??t?ry ?f G?? ?nd f?c?l?ty l?c?t??n

Th? ??t?ng (?.?., l?c?t??n) ?nd ?l?c?m?nt (?.?., ?r??nt?t??n) ?f ? m?j?r f?c?l?ty ?uch ?? ? r??dw?y, f?ct?ry, ?r h?u??ng ?r?j?ct h?? l?ng b??n ? ?ubj?ct ?f ?nt?r??t ?n th? f??ld ?f l?nd?c??? ?rch?t?ctur?. ?uch ?r?bl?m? c?n b? qu?t? "w?ck?d" . F?r ?x?m?l?, th? r?ut?ng ?f ? fr??w?y ??gm?nt ?n ?n urb?n ?r?? mu?t m??t ? numb?r ?f c?m??t?ng ?bj?ct?v??. T? ?cc?m?l??h ? t??k ?uch ?? r??d l?c?t??n, McH?rg ?r?????d ?n ???r??ch wh?ch d??l? w?th th? ?r???r?t??n ?f ? numb?r ?f m???, ??ch w?th ? d?ff?r?nt th?m?. ??ch l?nd-b???d un?t ?n ? m?? (wh?th?r r??t?r ?r v?ct?r-b???d) w?uld b? c?l?r?d fr?m l?ght (v?ry ?u?t?bl?) t? d?rk (n?t ?u?t?bl? ?r c?m??t?bl?). ??ch m?? w?uld r??r???nt ? th?m? ?uch ?? curr?nt l?nd-u?? c?m??t?b?l?ty (m?ny ?th?r ?m??rt?nt th?m?? ?x??t ?? w?ll: ?r???nc? ?f w?tl?nd?, ???l ?r???rt???, ?l???, h??t?r?c?l ?tructur??, ?tc.). F?r McH?rg, ?uch m??? w?r? dr?wn ?n cl??r ?ct?t?t? ?h??t?. By ?u??r?m????ng th? ?h??t? ?n t?? ?f ??ch ?th?r ?nd v??w?ng th? c?m????t? m?? ?f ?ll c?l?r? ?nd th?m??, ?r??? wh?ch ?????r l?ght ?r? h?ghly ?u?t?bl? ?nd th??? th?t ?r? d?rk ?r? n?t. McH?rg th?n ?rgu?d th?t th?? ?nf?rm?t??n ?? ? m?? c?uld th?n b? u??d t? ?d?nt?fy th? b??t r?ut? c?nn?ct?ng tw? ???nt? ?r ?d?nt?fy?ng th? b??t l?c?t??n f?r ? ???c?f?c funct??n. Much ?f th? ??t? ?u?t?b?l?ty ?n?ly??? ut?l?z?d ?n G?? t?d?y r???mbl?? th? b???c m????ng ?d??? ?x????d by McH?rg.

Br?dg?ng b?tw??n tr?d?t??n?l l?c?t??n m?d?l? ?nd G??

Wh?n R?v?ll? ?nd ?w??n f?r?t ?ubl??h?d ?n ?nt?g?r l?n??r ?r?gr?mm?ng f?rmul?t??n ?f th? ?-m?d??n ?r?bl?m, th?y g?v? r??ult? b???d u??n ? 55 n?d? d?t? ??t. ?ub??qu?nt t??t?ng ?nd ?n?ly??? h?? r?u??d th?? d?t? ??t num?r?u? t?m??. ?n 1970, f?w d?t? ??t? ?f ???t??l d?m?nd ?x??t?d, ?nd wh?t ?x??t?d w?r? ?m?ll (?.?., l??? th?n 75 n?d??). ?n? m?j?r ?l?m?nt c?ntr?ll?ng ?r?bl?m ??z? w?? th? f?ct th?t m??t ?r?bl?m? th?t w?r? l?rg?r th?n 75 n?d?? c?uld n?t b? ??lv?d ??t?m?lly. ? furth?r c?m?l?c?t??n w?? th?t d?t? f?r l?c?t??n m?d?l? w?r? ?l?? c?ll?ct?d ?n ??m? ?ggr?g?t?d f?rm. F?r ?x?m?l?, th? ?w??n 55 n?d? d?t? ??t r??r???nt?d th? c?ntr??d? ?f 55 ???t?l c?d?? ?n th? W??h?ngt?n, DC m?tr??l??t?n ?r??. Th? f?r?t ?ubl??h?d c?m??r???n ?f ??v?r?l ???r??ch?? t? ??lv?ng th? ?-m?d??n ?r?bl?m ut?l?z?d ? 49 n?d? d?t? ??t r??r???nt?ng ? ?m?ll r?g??n ?f ?nd?? . W?th G??, d?t? c?n b? ch?r?ct?r?z?d ?t ? f?n?r l?v?l ?f d?t??l ?r ?c?l?. ?t ?? ?????bl? t? r??r???nt ? mun?c???l?ty ?t th? l?v?l ?f d??cr?t? d?m?nd (?.g., ?tud?nt ?ddr?????), ?r ??m? l?v?l ?f ?ggr?g?t??n l?k? bl?ck f?c??, ?ddr??? r?ng?? ?n ?tr??t ??gm?nt?, ?nt?r??ct??n?, ?tc. Th? ??z? ?f ?uch ?r?bl?m? c?n b? c?n??d?r?bly l?rg?r th?n th? ty?? ?f d?t? ??t? u??d ?n ???t l?c?t??n ?tud???. ??th?r d?m?nd ?? ch?r?ct?r?z?d ?t ?uch ? l?v?l ?r ?t ?? ?ggr?g?t?d. W?th th? ?v??l?b?l?ty ?f G??, th?? c?n b? ? r??l ch??c?.

?ft?n th? d?t? ?tructur?? th?t ?r? u??d t? ?t?r? ?nd m?n??ul?t? m?? ?nf?rm?t??n ?r? n?t th? ??m? ?? th??? u??d ?n th? ??lut??n ?f ? l?c?t??n m?d?l. F?r ? ???c?f?c l?c?t??n m?d?l, th? d?t? ?tructur? m?y b? ?m??rt?nt ?n ?rd?r t? ?u???rt ?n ?ff?c??nt ??lut??n c?d?. C?n??qu?ntly, ?t m?k?? ??n?? t? ?x??rt ???t??l d?t? ?nd tr?n?f?rm t? ? f?rm th?t ?? ?u?t?bl? f?r th? l?c?t??n ?lg?r?thm, ?x?cut? th? l?c?t??n ?lg?r?thm ?nd th?n tr?n?f?rm th? r??ult? b?ck ?nt? ? f?rm th?t c?n b? ?m??rt?d ?nt? th? G??. W? w?ll c?ll ?uch ?n ???r??ch t? l?c?t??n m?d?l?ng ?nd G?? ? l????ly c?u?l?d ???r??ch, wh?r? ? d?t? br?dg? ?? ??t u? t? ?x??rt ?nd tr?n?l?t? d?t? b?tw??n th? tw? ?tructur??. Th?? ?? th? ???r??ch t?k?n by ?nv?r?nm?nt?l ?c??nc? R????rch ?n?t?tut? (??R?) ?n d?v?l???ng th? c???b?l?ty f?r ??lv?ng ?-m?d??n ?r?bl?m? w?th th? ?RC/?NF? ?y?t?m. Th? ?RC/?NF? ?y?t?m c?lcul?t?? d??t?nc?? b?tw??n ??ch d?m?nd ???nt ?nd ?ll ?f th? f?c?l?ty ??t?? ?nd ?x??rt? th? d?t? t? ?n ?xt?rn?l d?t? f?l?. F?r ??ch d?m?nd ???nt th? d??t?nc?? t? th? f?c?l?ty ??t?? ?r? ?t?r?d ?n ?rd?r ?f ?ncr????ng d??t?nc?. ? ????r?t? ?rr?y ?tr?ng c?nt??n? th? ?nd?c?? ?f th? ????c??t?d ??t?? ?n th? ??m? ?rd?r. Th? d??t?nc? ?tr?ng? ut?l?z? th? f?rm?t ???c?f??d by D?n?h?m ?nd Ru?ht?n . Th?n, ?f ? d???r?d ?-m?d??n ?r?bl?m ?? t? b? ??lv?d, ?RC/?NF? th?n ?x?cut?? ? l?c?t??n h?ur??t?c th?t r??d? th? d??t?nc? ?tr?ng? f?l? ?nd ??lv?? th? l?c?t??n ?r?bl?m. ?RC/?NF? ?m?l?y? b?th th? T??tz ?nd B?rt h?ur??t?c ?nd th? Gl?b?l R?g??n?l ?nt?rch?ng? ?lg?r?thm (GR??) ?f D?n?h?m ?nd Ru?ht?n . Th?? l????ly c?u?l?d ???r??ch t?k?? ?dv?nt?g? ?f th? d?t? ?tructur? th?t h?? b??n d?v?l???d f?r th? l?c?t??n ?lg?r?thm ?? w?ll ?? th? d?t? ?tructur?? f?r th? G??. ?nc? th? m?d?l h?? b??n ??lv?d ? ??lut??n? f?l? ?? ?m??rt?d ?nt? ?RC/?NF? ?nd th? r??ult c?n b? d???l?y?d u??ng ??v?r?l ??t??n?. ?n ?x?m?l? ?f th? "???d?r d???l?y" f?r ? l?c?t??n ?r?bl?m ?? g?v?n ?n F?g. Th? r??ult? d???ct ? 4-m?d??n ?r?bl?m ??lv?d f?r d?t? d???ct?ng th? ?w??n 55 n?d? ?r?bl?m. Th? ?y?t?m ?? d???gn?d t? h?ndl? th?u??nd? ?f d?m?nd n?d?? ?nd th?u??nd? ?f f?c?l?ty ??t??.

??R? h?? m?d? ?t ?????bl? t? h?ur??t?c?lly ??lv? ?-m?d??n ?r?bl?m? ?nd d???l?y ??lut??n? u??ng ? G??. TR?N?C?D ?l?? ?r?v?d?? th? c???b?l?ty ?f ??lv?ng l?c?t??n ?r?bl?m? w?th G???lu?. ?t ?? r????n?bl? t? ?x??ct th?t ?th?r ?y?t?m? w?ll ?m?rg? ?n th? n??r t?rm th?t w?ll ?r?v?d? th?? c???b?l?ty ?? w?ll. Th? c???b?l?ty ?f ??lv?ng ? ?-m?d??n ?r?bl?m m?y ???m ??m?w?ht l?m?t?d ?t f?r?t, but u??n cl???r ?b??rv?t??n, ?n? c?n ????ly ??? th?t ? ?-m?d??n ??lut??n h?ur??t?c c?n ?l?? ??lv? c?v?r?ng ?nd ?tt?nd?nc? m?d?l? [28 ?nd 29]. ?n f?ct, th? ?RC/?NF? ?y?t?m w?th th? n?tw?rk m?dul? r??d?ly ??lv?? ?uch ?r?bl?m? ?? th? m?x?m?l c?v?r?ng l?c?t??n ?r?bl?m ?nd th? ?tt?nd?nc?-m?x?m?z?ng ?r?bl?m. T? m?k? ?uch ? m?d?l ?nt?gr?t??n r?bu?t r?qu?r?? ?ddr????ng ??v?r?l ?m??rt?nt ???u??. Th??? w?ll b? d??cu???d ?n th? n?xt ??ct??n ?f th?? ????r.

?x?m?l?? u??ng ?RC/?NF? ?n ? l????ly c?u?l?d m?nn?r c?n b? f?und ?n F?th?r?ngh?m ?t ?l. ?? w?ll ?? ?n Murr?y ?nd G?tt??g?n . G?rr?rd ?t ?l. ?r???nt ?n ???l?c?t??n u??ng th? ?RC/?NF? l?c?t??n m?d?l c???b?l?t??? ???l??d t? b??l?g?c?l r???rv? ??t? ??l?ct??n. Ruggl?? ?nd Church h?v? u??d ? G?? t? g?n?r?t? ?nd m??nt??n m?ny ?????bl? ?c?n?r??? f?r ?n ???l?c?t??n ?f ? l?c?t??n m?d?l t? h??t?r?c?l ??ttl?m?nt? ?n th? B???n ?f M?x?c?.

Curr?nt d?v?l??m?nt? ?n G?? ?nd l?c?t??n m?d?l?

R?V?ll? ?t ?l. w?r? th? f?r?t t? cl????fy l?c?t??n m?d?l? ?nt? tw? br??d cl????? ?f ?r?bl?m?: c?nt?nu?u? ???c? ?nd d??cr?t? n?tw?rk-b???d m?d?l?. L?c?t??n m?d?l d?v?l??m?nt h?? c?nc?ntr?t?d ?n th? l?tt?r ?f th??? tw? ?r???. ??m? ?f th?? m?d?l?ng b??? ?? b?c?u?? ? n?tw?rk c?n c??tur? ? numb?r ?f nu?nc?? ?f ???t??l v?r??b?l?ty th?t ?r? ?ft?n ???um?d ?w?y ?n ? unb?und?d, c?nt?nu?u?, ?l?n?r r??r???nt?t??n. ? n?tw?rk m?d?l m?y ?ccur?t?ly r??r???nt tr?v?l d??t?nc?? ?n ?n urb?n ?r??, wh?r??? ?n unb?und?d ?l?n?r m?d?l m?ght n?t wh?n num?r?u? b?rr??r? ?x??t. ?v?n th?ugh ?xt?n???n? t? ?l?n?r m?d?l? th?t ?ll?w b?rr??r? ?nd g?t?? ?x??t, f?w h?v? ?x?l?r?d ?uch c?nc??t?; ??? L?r??n ?nd ??d?q ?nd D?ng ?t ?l. . R??r???nt?ng d?m?nd? ?? c?nt?gu?u? ?r??? ?n?t??d ?f ???nt? ?l?? m?k?? ??n?? t?: but th?? ?? ?l?? r?r?ly c?n??d?r?d ?n ? m?d?l; ??? f?r ?x?m?l? W???l?w?ky ?nd L?v? , ?nd M?ll?r . ?n ?dd?t??n, ?nly ? f?w hybr?d m?d?l? ?f ?l?n?r ?nd n?tw?rk ??r?d?gm? ?x??t . ?v?n th?ugh ?uch c?n?truct? ?x??t ?n th? l?c?t??n l?t?r?tur?, th?y r?qu?r? ??gn?f?c?nt ???t??l d?t??l t? r??l??t?c?lly d??cr?b? ? r??l-w?rld ?r?bl?m. H?v?ng ?uch ???t??l d?t??l ?r???nt ?n G??? h?? l?d t? ? c?nt?nu?ng ?nd gr?w?ng ?nt?r??t ?n ?uch l?c?t??n c?n?truct? ?n th? G?? l?t?r?tur?. Th?? d??? n?t m??n th?t ?uch m?d?l? ?nd c?n?truct? h?v? n?t b??n ?f ?nt?r??t ?ut??d? ?f th? f??ld ?f G??, but th?t r??l ?l?nn?ng ?r?bl?m? n??d th? d?t? ?n ? f?rm ?nd r???lut??n ty??c?lly f?und ?n th? G??. ?uch l?c?t??n ?r?bl?m? ?nclud? c?rr?d?r l?c?t??n, c?llul?r t?l??h?n? tr?n?m?????n ??t? l?c?t??n, f?r? w?tcht?w?r l?c?t??n, ?tc. C?rr?d?r l?c?t??n ?nv?lv?? ?d?nt?fy?ng th? b??t r?ut? ?r r?ght?-?f-w?y f?r f?c?l?t??? ?uch ?? ????l?n?? ?nd tr?n?m?????n ??w?r l?n??. Th?y c?uld ?l?? ?nv?lv? th? r?ut? ?f ? r??d t? m?x?m?z? v???b?lty ?f ? b??ut?ful l?nd?c???, t? m?n?m?z? c??t ?f r??ch?ng ??m? r???urc? ?r t? m?n?m?z? th? v??w ?r ch?nc? ?f b??ng d?t?ct?d. W?tcht?w?r? ?nd c?llul?r t?l??h?n? tr?n?m?????n ??t?? r??r???nt f?c?l?t??? th?t m?x?m?z? ?r??l c?v?r?g? w?th?n ? d?r?ct, l?n?-?f-??ght, tr?n?m?????n ?r v??w.

?n ?x??nd?d v?r???n ?f th? v??w?h?d ???nt l?c?t??n ?r?bl?m w?uld ?nv?lv? d?t?rm?n?ng th? ??t?m?l h??ght? ?f th? t?w?r? ?nd th??r l?c?t??n ?n ?uch ? m?nn?r th?t th? gr??t??t ?r?? ?f th? l?nd?c??? ?? w?th?n v??w. Th? ?n?-???nt w?tcht?w?r l?c?t??n ?nd h??ght ??t?m?z?t??n ?r?bl?m h?? b??n ??lv?d by ?h?r?r . Th? ???l?c?t??n ?f th?? ty?? ?f ?r?bl?m ?? num?r?u?, ?nv?lv?ng c?mmun?c?t??n ?x?m?l?? fr?m tr?n?m?????n r????t?r? t? c?llul?r t?l??h?n? ?y?t?m?. Much ?f th? w?rk ?n ??l?ct?ng c?mmun?c?t??n ??t?? ut?l?z?? G??, ??nc? th? G?? ?r?v?d?? th? c???b?l?ty ?f g?n?r?t?ng v??w?h?d? ?nd r?duc?? th? c??t ?f ?nd???nd?nt ??ftw?r? d?v?l??m?nt.

?n?th?r c?nt?nu?u? t?rr??n-b???d l?c?t??n m?d?l c?n b? f?und ?n f?r??try m?n?g?m?nt. Th?? ?r?bl?m ?nv?lv?? d???gn?ng ? h?rv??t?ng ?y?t?m wh?ch c?n b? u??d t? ?ff?c??ntly h?rv??t t?mb?r ?cr??? ? ?t??? l?nd?c???. H?rv??t?ng c?n b? ?cc?m?l??h?d fr?m ? t?w?r ?nd ? c?bl?. Th? c?bl? ?? ?tr?tch?d ?nd ?nch?r?d d?wn ?l??? fr?m th? t?w?r. Tr??? ?r? f?ll?d ?nd r????d u? ?l??? t? th? t?w?r by ? l?n? th?t ?? ?u???nd?d fr?m ? ?ull?y fr?m th? ?nch?r?d c?bl?. ? c?bl? ?nd t?w?r-h?rv??t?ng ?l?n ?? d???ct?d ?n F?g. ???um? th?t th? h?rv??t?ng ?r?? ?? d?v?d?d ?nt? ? numb?r ?f gr?d c?ll?. ?f ? h?rv??t?ng t?w?r ?? l?c?t?d ?n ?n? gr?d c?ll, ?t ?? th?n ?????bl? t? ?d?nt?fy ?ll d?wn ?l??? c?ll? th?t c?n b? r??ch?d fr?m ? c?bl? ?nch?r?d ?t ???r??r??t? ????t??n?. Furth?r, g?v?n th? ?l???, d??t?nc? ?f c?bl?w?y ?nd ty?? ?f t?mb?r, ?t ?? ?????bl? t? d?t?rm?n? th? c??t ?f h?rv??t?ng ? g?v?n c?ll fr?m ? t?w?r ?n ? g?v?n l?c?t??n. Th?? c?n b? ?cc?m?l??h?d f?r ?ll ??t?nt??l h?rv??t t?w?r l?c?t??n?. W??ntr?ub h?v? d?v?l???d ? m?d?l wh?ch ??t?m?z?? h?rv??t t?w?r l?c?t??n? ?? w?ll ?? r??d c?nn?ct??n? n??d?d t? r??ch th? h?rv??t t?w?r? wh?ch m?n?m?z?? c??t ?f l?g tr?n???rt ?nd t?mb?r h?rv??t?ng. Th?? m?d?l ?? l????ly c?u?l?d w?th th? ?RC/?NF? G??. ?t ? c?m?ut?r c?n??l? ? h?rv??t ?ng?n??r ??l?ct? ??t?nt??l t?w?r l?c?t??n? ?n ? m?? ?f th? l?nd?c??? w?th ? m?u??. Th? ?y?t?m th?n g?n?r?t?? th? ?????bl? c?bl? ??t-u?? ?nd d?t?rm?n?? th? c??t ?f h?rv??t?ng ??ch c?ll fr?m t?w?r ????t??n? th?t c?n r??ch th?t c?ll. D?t? ?n ??t?nt??l r??d l?nk?g?? ?r? ?l?? g?n?r?t?d wh?ch ?r? ?ub??qu?ntly ?x??rt?d t? th? r??d bu?ld?ng ?nd t?w?r l?c?t??n m?d?l. V?r??u? ?ch?m?? h?v? b??n d?v?l???d t? ??lv? th?? m?d?l ?nclud?ng T?BU ???rch ?nd L?gr?ng??n r?l?x?t??n.

? ??c?nd ?x?m?l? ?n ???t??l ?ll?c?t??n ?nv?lv?ng f?r??try ???r?t??n? ?? th? ?ll?c?t??n ?f c?nt?gu?u? bl?ck? ?f tr??? f?r h?rv??t?ng. ?n ?r?? ?? ty??c?lly d?v?d?d ?nt? ???t??l un?t? c?m?r???d ?f ?t?nd? ?f tr???. ?t?nd? ?f tr??? ?r? gr?u??d ?nt? l?rg?r un?t? c?ll?d bl?ck?. ??ch bl?ck ?? r?l?t?v?ly c?m??ct ?nd ??z?d und?r ??m? m?x?mum l?m?t. N? tw? ?dj?c?nt bl?ck? c?n b? h?rv??t?d ?n th? ??m? d?c?d?. Th? ?bj?ct?v? ?? t? ?ll?c?t? bl?ck? ?r h?rv??t un?t? t? ? h?rv??t ??r??d ?uch th?t th? n?t r?v?nu?? ????c??t?d w?th h?rv??t?ng ?r? m?x?m?z?d. ?f ??ch ???t??l un?t c?n b? r??ch?d by ?x??t?ng r??d?, th?n th? ?r?bl?m c?n b? ?x?r????d ?? ? ??t? ??l?ct??n ?r?bl?m w?th ?dj?c?ncy c?n?tr??nt? ??m?l?r t? th??? ?x?r????d by M??n ?nd Ch?udry f?r th? c?nd?t??n?l c?v?r?ng l?c?t??n ?r?bl?m. Th? ?r?bl?m b?c?m?? m?r? c?m?l?x ?f ?x??t?ng r??d? c?nn?t r??ch ?ll un?t?. Th?n r??d? ?nd t?m?ng ?f r??d bu?ld?ng b?c?m?? ?n ?m??rt?nt but c?m?l?c?t?ng f?ct?r t? th? ?r?bl?m. M??t ???l?c?t??n? ?f th?? ty?? ?f m?d?l ?r? n?w ?nt?gr?t?d w?th ??m? f?rm ?f G??. Th?? ty?? ?f ?r?bl?m ??lut??n, f?r ?x?m?l?, h?? b??n l??t?d ?? ? n??d?d funct??n ?n th? U?. F?r??t ??rv?c?'? G?? ?cqu???t??n ?r?gr?m. ?x?m?l?? ?f th?? ty?? ?f ?r?bl?m ?nd ??lut??n ?r?c?dur?? c?n b? f?und ?n Murr?y ?nd Church , J?n?? ?t ?l., ?nd ?nyd?r ?nd R?V?ll? .

C?nclu???n?

G??gr??h?c?l ?nf?rm?t??n ?y?t?m? ?nv?lv? ??ftw?r? th?t ?r?v?d?? ?t?r?g?, r?tr??v?l, ?n?ly???, v??u?l?z?t??n, ?nd m????ng c???b?l?t??? f?r ???t??l d?t? ?uch ?? r??d n?tw?rk?, l?nd u?? ?nf?rm?t??n, c?n?u? tr?ck d?t?, ?tc. ??m? G??? ?nclud? ?mb?dd?d l?c?t??n m?d?l? ?nd m??t ?r?v?d? th? ????rtun?ty t? ?nt?gr?t? l?c?t??n m?d?l? w?th?n ? m??-b???d gr??h?c?l u??r ?nt?rf?c?. B?c?u?? G?? c?n b? u??d t? ????mbl? d?t? fr?m v?r??u? ??urc?? ?nv?lv?ng d?ff?r?nt m?? ?c?l?? ?nd tr?n?f?rm?t??n?, ?t c?n b? ? ??gn?f?c?nt ??d t? th? l?c?t??n ?n?ly?t. ?v?n th?ugh l?c?t??n ?tud??? n??d n?t ?nv?lv? th? u?? ?f GL?, th?r? ?? much t? b? g??n?d by t?k?ng ?dv?nt?g? ?f th? funct??n? th?t ?r? ?v??l?bl? ?n G?? ??ftw?r?, ?nd ?v??l?bl? ?n d?t?b???? th?t c?n b? ?urch???d. F?r?t, ??m? ?f th? ??ftw?r? f??tur?? ?u???rt n??d?d f?r ???r?t??n? ?n ? l?c?t??n m?d?l ???l?c?t??n. Th??? m?y ?nclud?: d?t? ?ntry, m????ng, ??lut??n ?r???nt?t??n, ?ut?ut, ???t??l d?t? ?rg?n?z?t??n, ?nd ???t??l m???ur?m?nt (?.g., d??t?nc? m?tr?x). ?n m?ny c???? ?t w?uld n?t b? c??t ?ff?ct?v? t? ?nd???nd?ntly d?v?l?? ?uch ??ftw?r? funct??n? f?r ? l?c?t??n ?tudy. ?t ?? ?????bl?, f?r ?x?m?l?, t? d?v?l?? ? ?y?t?m th?t c?n g?n?r?t? ? T?N ?r ? v??w?h?d f?r ? c?llul?r t?l??h?n? l?c?t??n ?tudy, but ?t c?uld b? ? f?r ??m?l?r t??k t? ?nt?gr?t? th? u?? ?f ? G?? ?y?t?m t? ?r?v?d? ?uch funct??n?l?ty wh?n n??d?d. ??c?nd, ? gr?w?ng d?t? d?v?l??m?nt ?ndu?try ?u???rt?d ?r?m?r?ly by G?? u??r? n?w m?k?? ?r ??ck?g?? ? numb?r ?f d?t? ?r?duct? wh?ch c?uld h?v? ??gn?f?c?nt v?lu? ?n l?c?t??n ?tud???. ?uch d?t? ?? n?m?n?lly ?r?v?d?d ?n mult??l? G?? f?rm?t?. Th?rd, G?? ??ftw?r? ?ft?n u??? ?t?t?-?f-th?-?rt d?t?b??? ?ng?n?? ?nd ?? d???gn?d t? h?ndl? l?rg? v?lum?? ?f d?t?. ?uch ??ftw?r? c?n ?bl?v??t? th? n??d t? d?v?l?? ?nd???nd?ntly ? ???t??l d?t? b??? ?ng?n?. ?t c?n ?l?? ?r?v?d? d?t? ????mbly ??rv?c?? f??t?r th?n ?th?rw??? ?????bl? w?th?ut ??gn?f?c?nt d?v?l??m?nt.

?n th? n?g?t?v? ??d?, ?n? mu?t r?c?gn?z? th?t th?r? ?r? c??t? t? b?th ??ftw?r? ?nd d?t? ?cqu???t??n. ?uch c??t? m?y n?t b? ju?t?f??d ?n t?rm? ?f ?n ???l?t?d ?r?j?ct; but, ?n ?ny c?rcum?t?nc? wh?r? th? c??t? ?f th? G?? ?nd n??d?d ?x??rt??? c?n b? ?v?r?g?d ?v?r mult??l? u???, G?? m?y b? th? c??t-?ff?ct?v? ?lt?rn?t?v?. ?? n?w ??ftw?r? ?? br?ught ?n-l?n? ?nd ?x??rt??? ?? d?v?l???d ?m?ng l?c?t??n ?c??nt??t?, ?t ?? h?rd t? ?m?g?n? th?t G?? w?ll ?r?v?d? ?nly ? ?u???rt?ng r?l? ?n l?c?t??n r????rch, ?? m?ny n?w m?d?l? ?r? ?????bl? wh?n v??w?d fr?m ? G?? ??r???ct?v?. ?n f?ct, d?m?nd f?r b?tt?r l?c?t??n m?d?l funct??n?l?ty ?n G?? ??ftw?r? w?ll gr?w. ?t ?? ???y t? c?nclud? th?t th? ?ucc??? ?f m?ny l?c?t??n ???l?c?t??n? ?n th? futur? m?y b? ?nt?m?t?ly t??d t? G??.

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