AUTOMATED ROAD EXTRACTION AND UPDATING USING THE ATOMI SYSTEM - PERFORMANCE COMPARISON BETWEEN AERIAL FILM, ADS40, IKONOS AND QUICKBIRD ORTHOIMAGERY

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1 AUTOMATED ROAD EXTRACTION AND UPDATING USING THE ATOMI SYSTEM - PERFORMANCE COMPARISON BETWEEN AERIAL FILM, ADS40, IKONOS AND QUICKBIRD ORTHOIMAGERY E. Bltsvis, L. O Sullivn, C. Zhng Institute of Geoes n Photogrmmetr, Swiss Feerl Institute of Tehnolog (ETH) Zürih, ETH-Hönggererg, CH-8093 Zürih, Switzerln - (hunsun, mnos)@ geo. ug.ethz.h Swiss Feerl Offie of Topogrph, Seftigenstr. 264, CH-3084 Wern, Switzerln - Lim.OSullivn@swisstopo.h Commission III, Working Group III/4 KEY WORDS: 3D ro reonstrution, utomtion, upting, mpping, performne evlution, orthoimge, IKONOS, Quikir, igitl irorne sensor, high-resolution stellites ABSTRACT: In the reent ers, the utomte etrtion of ros from igitl imges hs rwn onsierle ttention ue to the nee for the effiient quisition n upting of ro t for geotses. The evelopment of new igitl eril sensors n high-resolution stellite sensors signifies revolutionr hnge in imge quisition n the possiilit of full igitl proessing from imge quisition to the genertion of vlue-e prouts for vrious pplitions. At ETH Zurih in oopertion with n fune the Swiss Feerl Offie of Topogrph (swisstopo), we hve evelope n opertionl sstem for the utomte etrtion of 3D ro networks from imger tht integrtes the proessing of olour imge t n eisting igitl sptil tses. The sstem fouses on rurl res, n use stereo or orthoimges n n etermine 3D ro es, n possil other ttriutes like with if the ros hve minimum with of. 3 piels. Colour is of vntge ut not must, while DTM or DSM is require. If no ro tse eists, it n e generte from srth, using mnul mesurement of hrteristi ro see points. The sstem hs een etensivel teste, minl swisstopo, on res with iverse terrin relief n lnover tpes using ifferent resolution stereo n orthoimges with goo results. Reentl, tests hve een performe using ADS40, IKONOS n Quikir t. This pper reports on the performne omprison of the ATOMI sstem using ifferent sensor t in two vring test sites. The test results were qulittivel n quntittivel nlse using urte referene t. Visul nlsis n quntittive mesures of ur, orretness n ompleteness re presente, with tpil ompleteness n orretness vlues of over 90% n plnimetri ur of 0.4 m to 1 m. The vntges n isvntges using ifferent sensor t for ro network upting re lso isusse. 1. INTRODUCTION In moern mp proution, shift hs tken ple from mps store in nlogue form on pper or film to igitl tse ontining topogrphi informtion. A igitl topogrphi tse is n essentil prt of GIS. Reentl, Ntionl Mpping Agenies (NMAs), espeill in Europe, wish to generte igitl lnspe/topogrphi moels tht onform to relit n o not inlue mp genertion effets. In ition, vrious eisting n emerging pplitions require up-to-te, urte n suffiientl ttriute igitl t, espeill of ros n uilings, inluing r nvigtion, tourism, trffi n fleet mngement n monitoring, intelligent trnsporttion sstems, internet-se mp servies, lotion-se servies, et. In 2002, two mjor Europen mp proviers n five r mnufturers strte the projet NetMAP to ientif n evlute the ro tse requirements for in-vehile ITS (Intelligent Trnsporttion Sstems) n servies pplitions, s well s the ost onsequenes involve for t pturing n t proution tehniques ( Also in 2002, twelve orgnistions from NMAs, ro ministrtions n privte setor ke plers of ro t mrket sumitte the HERDS (Hrmonize Europen Ro Dt Solution) projet proposl for EC funing. Furthermore, in the Europen Territoril Mngement Informtion Infrstruture projet, ros re mentione together with elevtion n hrogrph s the onl ojets, ommonl gree to e importnt enough to e efine s referene t, neee most pplitions (see /hpter1.pf). To ope with higher prout emns, inrese the proutivit n ut ost n time requirements, utomtion tools in the proution shoul e emploe. As eril imges re mjor soure of primr t, it is ovious tht utomte eril imge nlsis n le to signifint enefits. In ition, the evelopment of new igitl eril sensors n high-resolution stellite (HRS) sensors signifies revolutionr hnge in imge quisition n the possiilit of full igitl proessing from imge quisition to the genertion of vlue-e prouts for vrious pplitions. At ETH Zurih, in oopertion with the Swiss Feerl Offie of Topogrph (swisstopo), we hve evelope prtil sstem for the utomti etrtion of 3D ro networks from imger tht integrtes proessing of olour imges n eisting igitl sptil tses, within the projet ATOMI. Some reports on the sstem performne n e foun in Bltsvis n Zhng (2003) n Zhng (2003). This pper reports on the performne of the ATOMI sstem using etensive res with vring relief n lnover n imges from ifferent sensors. 2. BRIEF DESCRIPTION OF PROJECT ATOMI 2.1 Aims of ATOMI The im of ATOMI is to upte ros igitise from 1:25,000 sle mps (prt of the ntionl VEC25 tset) fitting them

2 to the rel lnspe, improve their plnimetri ur to 1m n erive ro enterline heights with n ur of 1 to 2 m. The topolog n the ttriutes of the eisting tsets shoul e mintine. This upte shoul e hieve using the imge nlsis tehniques evelope t the Institute of Geoes n Photogrmmetr, ETH Zurih (IGP). The whole proeure shoul e implemente s stnlone softwre pkge, shoul e opertionl, fst, n most importntl relile. We o not im t full utomtion (. 80% ompleteness is plusile trget), ut the orret results shoul e rell orret to voi heking mnull the whole tset. After some initil work, the ims of ATOMI were restrite to improvement of the VEC25 (i.e. no etrtion of new ros) with the first trget eing the open rurl res. More etils of ATOMI n e foun in Eienenz et l. (2000). The stnr input t use inlues 1:16,000 sle olour imger, with 30-m fol length, n 60%/20% forwr/sie overlp, snne with 14 mirons t Zeiss SCAI, ntionwie DTM (DHM25) with 25-m gri sping n ur of 1-3/5-8 m in lowlns/alps, the vetorise mp t (VEC25) of 1:25,000 sle, n the rster mp with its 6 ifferent lers. The VEC25 t hve RMS error of m n mimum error of m, inluing generlistion effets. The re topologill orret, ut ue to their prtl utomte etrtion from mps, some errors eist. In some ses, DSM t in the working re ws generte using mthing (without susequent eiting) on ommeril igitl photogrmmetri worksttions with 2-m gri sping. In the mentime, muh etter DTM n DSM (with 2-m sping n 0.5-m n 1.5-m ur in nonforest n forest res) proue irorne lser snning eists for lrge res n will e soon finishe for ll Swiss regions up to 2000 m height, ut hs not een use up to now. 2.2 The Ro Reonstrution Sstem Our evelope sstem mkes full use of ville informtion out the sene n ontins set of imge nlsis tools. The mngement of ifferent informtion n the seletion of imge nlsis tools re ontrolle knowlege-se sstem. In this setion, rief esription of our strteg is given. We refer to Zhng (2003) for more etils. The initil knowlege se is estlishe the informtion etrte from the eisting sptil t n ro esign rules. This informtion is forme in ojet-oriente multiple ojet lers, i.e. ros re ivie into vrious sulsses oring to ro tpe, lnover n terrin relief. It provies glol esription of ro network topolog, n the lol geometr for ro sulss. Therefore, we voi eveloping generl ro moel; inste speifi moel n e ssigne to eh ro sulss. This moel provies the initil 2D lotion of ro in the sene, s well s ro ttriutes, suh s ro lss, presene of romrks, n possile geometr. A ro is proesse with n pproprite metho orresponing to its moel, ertin fetures n ues re etrte from imges, n ros re erive proper omintion of ues. The knowlege se is then utomtill upte n refine using informtion gine from previous etrtion of ros. The proessing proees from the esiest sulsses to the most iffiult ones. Sine neither 2D nor 3D proeures lone re suffiient to solve the prolem of ro etrtion, we mke the trnsition from 2D imge spe to 3D ojet spe s erl s possile, n etrt the ro network with the mutul intertion etween fetures of these spes. The sstem n etrt ros with minimum with of. 3 piels. It fouses on etrtion of ros in open rurl res, eluing ros in forest n urn res using the eisting informtion out the orers of these lnover lsses. The eisting ro tse informtion is use not onl for giving n pproimte position ut lso () to rige n fill-in gps in the etrte ros, n () to op this informtion in nonproesse res (forest, urn) n onnet it to the etrte ro network in open rurl res. The im of these two usges is to provie s finl result omplete network (even if prtill inorret) voiing results whih onsist of set of roken n unonnete ro segments. The sstem hs een moifie to work lso with orthoimges, where the 3D informtion is etrte overling the 2D informtion on the DSM or DTM. Although orthoimges hve ertin isvntges ompre to 2 or more imges, the min eing the inuries introue the DTM/DSM uring their genertion, the re muh esier to hnle, re sensor inepenent n most importntl le to reue input t n muh fster proessing, ruil ftor for opertionl proution. Our sstem inlues tools for eternl evlution of the etrte results, ompring the etrte results with preise referene t. The qulit mesures use in this work im t ssessing ompleteness n orretness s well s geometri ur. Completeness mesures the perentge of the referene t tht lies within the uffer of the etrte ros, while orretness is the perentge of the etrte ros within the uffer of the referene t (Heipke et l., 1998). The uffer istne is efine using the require ur of the projet ATOMI, i.e. 1 m. The geometri ur is ssesse the men n RMS of the istnes etween the etrte ros n the referene t. The etile esription for the omputtion of the eternl evlution mesures is presente in Zhng (2003). The evelope sstem hs een implemente s stn-lone pkge initill on SGI pltforms for stereo n orthoimges n hs een porte to Winows XP onl for orthoimge proessing, with the sme user interfe. The sstem imports imger, the eisting ro tse n other input t (e.g. DSM/DTM). The etrte ro network s well s the ompute ro ttriutes inluing length n with re sve in 3D Ar/Info Shpefile formt tht is reil importe into eisting GIS softwre. For the tehnil etils of the sstem, we refer to Zhng (2003, 2003). The Winows XP version for orthoimges is terme ATOMIRO (with R stning for ros n O for orthoimges). All urrent n further improvements of the sstem n the tests reporte here refer to ATOMIRO, while the SGI versions hve een frozen. 3. TEST SITES AND DATA DESCRIPTION Results from two test sites in Switzerln will e presente here, one in Thun n the other one lose to the it of Genev. The seletion is minl se on the onsiertion tht the test sites shoul over s mn tpes of tpil lnover in Switzerln s possile. Another onsiertion is the vililit of imges from multiple sensors. Both sites re in open rurl res ut with ifferent lnover. All ro tpes in Switzerln n e foun in the res. The esription of the test sites n the ville imger re liste in Tle 1. Fig. 1 shows eril imges of the two test sites. Muh lrger n ifferent regions hve een use for tests swisstopo with totl ro length of out 9,000 km.

3 In Thun, the olour orthoimges were proue swisstopo from eril imges of sle 1:16,000 using the DHM25. The 50- m orthoimge is prt of the ntionwie tset Swissimge (proue from 1:30,000 imger with 15 m lens) with plnimetri ur of out 1 m. The imges for 20 m n 60 m were tken in spring 2003, n for 50 m in summer An orthoimge rete from ADS40 summer imges using the DHM25 is lso ville. Due to weknesses in the ontrol point istriution n the unle justment of the ADS40 imges, isrepn etween the ADS40 orthoimge n the 20m orthoimge hs een oserve. A non-ehustive omprison with mnull selete feture points shows tht the isrepn vries etween 0 n 80 m. However, smller ifferenes lso eist etween the 1998 n 2003 eril film orthoimges, use errors in the sensor orienttion. Thus, the rel ur of ro etrtion in imge spe is higher thn the ur vlues erive from omprison etween tsets (inl. the referene t), whih hve vring orienttion errors. Thun Genev Are (sq. km) 2.66 * * 3.0 Height rnge (m) 560 ~ ~ 1200 Lnspe Open rurl, Villges, Mn smll settlements Open rurl, Severl villges, Forest, Lrge fiels with re soil Imger tpe (orthoimge piel size) eril film (20m, 50m, 60m) ADS40 (30m) eril film (50m) IKONOS PSM (1m) Quikir PSM (70m) Tle 1. Test site esription n imge speifitions. Swissimge tset. IKONOS n Quikir imges were lso quire in M 2001 n Jul 2003 respetivel. The pnshrpene (PSM) orthoimges of IKONOS n Quikir were proue softwre sstem evelope t IGP using 2-m gri lser DTM with 0.5-m ur n h plnimetri ur of m, estimte using hek points mesure in 25-m orthoimges of the Cnton Genev, proue using the sme lser DTM (however with 1m gri sping) n with. 0.5-m plnimetri ur). The referene t for the Thun n Genev test sites were mesure mnull, swisstopo in 20-m piel size eril orthoimges n ETH Zurih in the Swissimge orthoimges, respetivel. The tests were performe on DELL PC with Pentium 4, 1.8GHz CPU n 1GB RAM running Winows XP. 4.1 Thun Site 4. RESULTS AND DISCUSSION Completeness n orretness is suffiient for ll imges in the Thun site, with slightl inferior results for the 50-m n 60-m piel size orthoimges. Although the piel size of the ADS40 imge is slightl more thn the 20 m of the eril film orthoimge, the results hieve re lmost ientil. Tpil results of ro reonstrution n juntion genertion re presente in Figs. 2-5, where the VEC25 n the etrte ros re shown s white n lk lines. In eh figure, (), (), () re the orthoimges with piel size 20 m, 50 m n 60 m respetivel, while the 30-m piel size ADS40 orthoimge is shown in (). Fig. 2 is sene with four-ro juntion. Ro surfe n ro sies re ler eept t the left sie of the figures, where tree olues the ro. The senes in Fig. 3 n Fig. 4 re slightl omple ompre with tht in Fig. 2. More shows n olusions re oserve. In the settlement res, some ro sies re not efine. In Fig. 5, first-lss ro is onnete with two thir-lss ros t two juntions. The romrks on the first-lss ro re visile in ll imges, ut re wek in the lower resolution imges. The emples show tht ros re generll orretl etrte from ll imges. Ro juntions re lso well forme. This oservtion is onfirme the eternl evlution of the etrtion results using the referene t (see Tle 2). To ount for the isrepn etween the ADS40 n eril film orthoimges, the uffer istne ws set to 2 m, when ssessing the results from the ADS40 orthoimge. Figure 1. Overview of test sites: () Thun, () Genev. The Genev test site (Fig. 1) is ner the it of Genev, ontining severl lrger villges, forest n river. Another ifferene to the Thun site is tht the sene ontins grsslns n lrge fiels of re soil. In ition, mn ro-like lines re oserve in the fiels. The eril orthoimge me from the Figure 2. Emples of ro etrtion n juntion genertion in senes with well efine ros.

4 n not onl on the groun piel size (whih is often use wrongl s snonmous to imge resolution n imge qulit). Figure 3. Emples of ro etrtion n juntion genertion in senes with smll settlements. Tle 2 lso shows tht ll qulit mesures re grull eteriorting with eresing piel size. One use for less ompleteness is tht pths in fiels re onl prtill etrte euse the pth surfe is lurre n ro eges re ver wek (Fig. 6), while in smll villges performne ws lso worse (Fig. 7). However, the qulit eteriortion is muh less thn the piel size reution. E.g. for 60-m vs. 20-m piel size, in the first se we hve 9 times less t, ut ompleteness, orretness n ur eteriorte onl 7.5%, 4.5% n 40%. On the other hn, this slight qulit erese m still men epensive itionl mnul eiting, so the question of piel size hoie shoul e refull onsiere. Qulit mesures Aeril Aeril 20m 50m Completeness (%) Corretness (%) Length of referene (km) Length of etrtion (km) RMS error (m) Men error (m) Proessing time (s) Aeril 60m ADS40 30m Tle 2. Qulit evlution of the results in Thun site. Figure 4. Emples of ro etrtion n juntion genertion in senes with smll settlements. Figure 6. A pth etrte in 20-m piel size imge (), ut onl prtill etrte in 60-m piel size imge (). The lk lines re the etrte results n the white lines re the referene t. Figure 5. Results in sene with first-lss ro. Our sstem elivers the est results with the 20-m orthoimge. Aout 95% of the ros re orretl etrte with n ur of out 50 m. The non-etrte or flsel etrte ros re minl in smll villges. Tking into ount the isrepn etween the ADS40 n the 20-m film orthoimge (s inite the lrge men vlues), our sstem performe equll well on ADS40 t. Inee, visul hek over the whole test site shows tht the results from ADS40 t re tull t the ro enters. Furthermore, imges from ADS40 re shrper n hve etter riometri qulit ompre to snne film. Imge qulit is importnt in generl n for ojet etrtion, n epens on suh imge properties s well, Figure 7. A villge ro etrte in 20-m piel size imge (), ut not in 60-m piel size imge (). The lk lines re the etrte results n the white lines re the referene t. Tle 2 shows tht the proessing spee of our sstem is high (e.g.. 30 minutes for more thn 40-km ros in 20-m piel size imges), n tht proessing time ereses lmost 1:1 with orthoimge piel size. The proessing time lso epens on the ro ensit n to lesser etent ompleit of the sene, inresing with them. Etensive tests t swisstopo with 50-m orthoimges show tht ros in n verge ro ensit 1:25,000 mp sheet overing 210 km2 n e etrte in 3-4 hours on Dell PC with Pentium 4, 2GHz CPU n 2GB RAM

5 running Winows XP. Thus, using this not up-to-te omputer onfigurtion, ll 1:25,000 mp sheets of Switzerln oul e proesse in 36 s. Note tht tpil mp sheets, eluing lrge urn enters, lrge lkes n the Alps, hve out 2,500 km of ros, with out 45%-50% of them in rurl res. shown in Fig. 10, where. 6.6-m wie 5th lss ro is inorretl etrte. 4.2 Genev Site Our sstem hieves goo results with the 50-m orthoimge (Swissimge), similr to the ones in Thun (see Tle 3). However, the performne (minl the ompleteness) with the HRS t is poor, espeill the 1-m IKONOS imge. In this imge, higher-lss ros re usull etrte, while most nrrow ros suh s 4th, 5th n 6th lss ros re not, euse the sstem prerequisite of 3 piel wie ros is not fulfille. The inrese groun resolution in Quikir mkes more ros visile thn in IKONOS, n lso the ro surfe n ro eges re lerer, resulting in etter performne. However, ompre with the 60-m eril film orthoimge in Thun, the ompleteness is still rther low. Qulit mesures Completeness Corretness Length of referene (km) Length of etrtion (km) RMS error (m) Men error (m) Proess time (s) Aeril 50m 90.89% 95.36% IKONOS-PSM 100m 54.22% 81.22% Quikir-PSM 70m 72.68% 89.58% Tle 3. Qulit evlution of the results in Genev site. It is pprent tht the efinition qulit of n ojet oes not epen onl on the piel size ut other imge qulit ftors too, n tht eh ojet tpe n e fvourl etrte within n ojet-speifi imge sle rnge. Critil ftors influening imge qulit, like tmospheri n illumintion onitions, sensor n sun elevtion n imge shrpness re muh less or not ontrollle with speorne sensors ompre to irorne ones, resulting thus in inferior imge qulit n ojet efinition with the former, even if the groun piel size is similr. Both HRS imges le to ur (RMS) of less thn 1m. The men vlues re high, ue to sstemti is use prole errors in the trnsformtion from the oorinte sstem of Cnton Genev to the Swiss oorinte sstem. Thus, in relit the ro ur from the HRS imges is similr or slightl etter thn tht from Swissimge, if the HRS orthoimges re proue with sumeter ur DSM/DTM (s in this se) or the sensor elevtion is high. Fig. 8 shows severl emples of etrte ros n ro juntions from the Swissimge, IKONOS n Quikir orthoimges. In the Genev test site, no etrtion is pplie to the ros insie the villges sine the sizes of the villges re lrge n re lssifie s urn re. The non-etrte ros re usull those in fiels with ver wek eges. An emple is given in Fig. 9. Flse etrtion in Swissimge ours when ro in fiels is neighouring with ro-like lines (Fig. 10). Severl flse etrtions re lso euse the tul ro with iffers from the with epete for the given ro lss. This ws notie with severl 5th n 6th lss ros. An emple is Figure 8. Emples of etrte ros n ro juntions in the Genev site orthoimges. The lk lines re the results n the white lines re the VEC25 ros. Left: Swissimge, mile: IKONOS, right: Quikir. Figure 9. Ro in fiel with wek eges n not e etrte from Swissimge. Blk line: referene t. White line: VEC25 ros. Figure 10. Emples of flse etrtion from Swissimge. Blk line: etrtion results. White lines: referene t. () ro is inorretl etrte ue to the interferene of mn ro-like fetures. () flse etrtion use ssuming wrong ro with for the given ro lss.

6 Fig. 11 presents two emples (3 imges in one row for eh) to show the limittion when our sstem is pplie to HRS t. In the figure, the VEC25 ros n etrte results re presente s white n lk lines respetivel, while the Swissimge, IKONOS n Quikir orthoimges re shown from left to right. In oth emples, the ros re etrte from Swissimge. The ro shown in the first sene (first row) is not etrte in the IKONOS imge, while the ro in the seon sene (seon row) n not e etrte in the HRS t ue to hze. Clous prohiit ro etrtion in the emple of Fig. 12. Figure 11. Emples showing limittions of our sstem pplie to HRS t. See tet for eplntion. The test shows tht the sstem performne is poor with the HRS t, espeill for 1-m IKONOS PSM imger. Both HRS n eliver sumeter ur, however the prolem lies with the poor ojet efinition n imge qulit. Onl hlf of the ros in the test sites re reonstrute, minl higher-lss ros with lrger with. The surfe of the nrrow ros (lowerlss ros) is usull lurre n the ro eges re wek n not ler in the HRS imges, thus most of the lower-lss ros re not etrte. The test results show tht the performne on the 70-m Quikir t is onsierl etter thn tht on the 1-m IKONOS t, ut still of lower ompleteness thn the 60- m piel size eril orthoimge. Other etrtion methos, not requiring ro withs (rions) of 3 piels or more, m e more pproprite for orthoimges with suh piel size. Genertion of Quikir orthoimges with 60 m, or eploment of new HRS with 40 m - 50 m groun piel size (liense for whih the US government hs lre provie) m pve the w for pplition of the urrent pproh with goo ompleteness even for suh imger, if the imging onitions re fvourle. Our sstem n still e improve, for emple, etter use of the eisting ro vetors to rige gps. Post-ontrol on whether the solution onforms in shpe n topolog to ro onstrution n intersetion priniples nees to e omplete. The self-ignosis n reliilit mesures erive for the etrtion results re not roust enough. Use of enser n more urte lser DSMs/DTMs n of the NIR hnnel of igitl sensors n e use for etter qulit results. Etension of the metho to res with low uilings n forest orers m e fesile. These n other spets will e topis of future reserh. ACKNOWLEDGEMENTS Figure 12. Emple showing lous in the Quikir imge preventing ro etrtion. Left: Swissimge, mile: IKONOS, right: Quikir. The VEC25 ro n etrtion results re presente in white n lk lines respetivel. 5. CONCLUSIONS In this pper, we hve reporte the performne omprison of the ATOMI ro reonstrution sstem etween eril film orthoimges of vring piel size, ADS40 n HRS orthoimges over two test sites in Switzerln, using ur, ompleteness n orretness quntittive mesures n visul ontrol. It is shown tht out 95% of ros in rurl res re orretl etrte using eril film n ADS40 orthoimges with 20-m n 30-m piel size, respetivel. With inresing piel size, the sstem performne eteriortes ut to muh less egree. However, even though the lnover of the two test sites is lrgel ifferent, our sstem hieve in oth. 90% ompleteness with 50m eril orthoimges. Thus, the generl onlusion is tht the ATOMI sstem n reonstrut ro networks in rurl res using eril orthoimges with mimum piel size of m with ompleteness n orretness of 90%-95% n n ur of m. The spee is suffiient for opertionl proution, while the result inlues oth etrte n non-etrte (ol) t resulting in omplete network with the topolog n ttriutes of the input ro tse plus new erive ttriutes like ro with. Using mnul on-sreen igitising of ro see points, the metho n e etene to genertion of ro tse from srth. We knowlege the finnil support n the t provie for this work n the projet ATOMI the Swiss Feerl Offie of Topogrph n the NPOC, Bern. Cnton Genev provie 25-m orthoimges, lser DSM n other t in the Genev test site. Spe Imging USA provie the Rtionl Polnomil Coeffiients for the IKONOS imges. We lso thnk Zhng Li, Henri Eiseneiss, Oliver Heller n Oliver Gut t ETH Zurih for proviing the orthoimges of IKONOS n Quikir. REFERENCES Bltsvis, E., Zhng, C., Automte upting of ro tses from eril imger. Pro. Workshop "Dt qulit in Erth Oservtion Tehniques", ITC, Enshee, The Netherlns, 21 Novemer. Eienenz, Ch., Keser, Ch., Bltsvis, E.P., ATOMI Automte Reonstrution of Topogrphi Ojets from Aeril Imges using Vetorize Mp Informtion. Interntionl Arhives of Photogrmmetr, Remote Sensing n SIS, Vol. 33, Prt B3/1, pp Heipke, C., Mer, H., Wieemnn, C., Jmet, O., Eternl evlution of utomtill etrte ro es. Photogrmmetrie Fernerkunung Geoinformtion (2), Zhng, C., Upting of rtogrphi ro tse imge nlsis. Ph.D. Thesis, Institute of Geoes n Photogrmmetr, ETH Zurih, Switzerln, Report No. 79. Zhng, C., Towrs n opertionl sstem for utomte upting of ro tses integrtion of imger n geot. ISPRS Journl of Photogrmmetr n Remote Sensing 58(3-4),