1 Introduction. Keywords: GNSS (GPS, GLONASS, GALILEO) and LPS (total stations, levelling) online and real-time

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1 GNSS/GPS/LPS based nlne Control Alarm System (GCA) - Mathematcal Models Techncal ealsaton of a System for Natural Geotechncal Deformaton Montorng Hazard Preventon. Jä ger F.González, Insttute of Appled esearch (IAF), Hochschule Karlsruhe für Technk und Wrtschaft - Unversty of Appled Scences. Moltkestrasse 3, D-7633 Karlsruhe. UL: Abstract. The research development project GCA (GNSS/GPS/LPS based nlne Control Alarm System) apples GNSS/GPS as well as classcal local postonng sensors (LPS) such as e.g. total sta - tons for a real-tme deformaton montorng. The GCA system may be set up as an early-warnngsystem for natural hazards, such as lsldes, mnng tunnelng actvtes, volcano montorng, also for the montorng of geotechncal structures buldngs. The GCA system conssts of GNSS/GPS/LPS sensors, whch are set up n the montorng area as a permanent array or as a moble montorng system. The GCA hardware-control communcaton software modules collect n dfferent knd of communcaton modes the GNSS/GPS/LPS data n a user defned samplng rate. The GCA deformaton-analyss software s responsble for a further processng of that data n a three steps sequental adjustment procedure. The st step ntalzes the montorng reference frame the coordnates covarance matrx consstng of stable reference ponts. The 2 nd 3 rd step comprse the georeferencng of the three-dmensonal objectpont coordnates n the reference frame, the smultaneous deformaton analyss respectvely. Both least squares robust estmaton technques (L- norm other so-called bounded nfluence M- estmators) are appled. The mathematcal models of the above three adjustment steps are presented. A frst focus s set on the robust onlne dsplacement estmaton, statstcal testng alarm settng. Further the algorthmc scheme of a L2- a robust L-norm Kalman flter are treated, whch are related to the object-pont state vector of dsplacements, veloctes acceleratons. Wth respect to the deformaton montorng n geotechncs of constructons, one of the further developments of the deformaton algorthms wll be set on the ntegraton both of further parameters (e.g. materal parameters, damage models), as well as of addtonal geotechncal sensors (e.g. stran-meters) by means of so-called system analyss, whch s based on deformaton FEM-approaches for statc dynamcs processes. Typcal project applcatons are shown as examples for the GCA-system. Keywords: GNSS (GPS, GLNASS, GALILE) LPS (total statons, levellng) onlne real-tme montorng system, envronmental montorng, geodetc deformaton analyss, robust estmaton Kalmanflterng, natural hazard dsaster preventon. Introducton The GCA system conssts of a set of GPS sensors communcaton unts set up n the montorng area two software packages, namely the GCA sensor communcaton software the GCA deformaton analyss software. The GCA computaton unt, called the "GCA-Center", conssts accordngly of a computer, where these two software components are runnng. Based on the GKA data nterface, the GCA communcaton software packages of the GCA cooperaton partners, namely MNIT of the GeoNav company, ( GCA_DC3 of the company Dr. Bertges ( are able to control any array of GPS/GNSS LPS sensors (fg. ), to provde the GPS/GNSS LPS data for the GCA deformaton analyss software (brefly GCA software). The structure of the GPS/GNSS LPS data nterface for the GCA deformaton analyss software, the so-called GKA fles, are adapted to the stard of the G- PS/GNSS baselne output the stard of LPS data (zenth angles, dstances, drectons, heght dfferences. Any local GCA-Center may be lnked over a long dstance to another PC, whch serves as a remote control staton, e.g. by Internet or a telephone lnk. In ths way several separate local or regonal projects can be montored smultaneously. The further evaluaton of the GKA baselne LPS data respectve onlne modelng of a three-dmensonal dsplacement, velocty acceleraton feld related deformaton functons are performed by the GCA software, whch has been developed by the GCA team Karlsruhe startng n 998 ( The GCA software sounds alarm, f a specfed crt-

2 cal state becomes sgnfcant durng an onlne montorng. The complete deformaton analyss functonalty s provded n a near onlne or n a post-processng mode respectvely. So the GCA system may be set up n an object area as a permanent array or as a moble "task force system" n areas, where danger becomes mmnent (Borchers Heer, 22; Bulowsk, 2; Korttke Palte 2; Lauterbach Krauter 22; Schä fer, 24; Kä lber Jä ger ). Fg. Desgn of a classcal absolute deformaton network realzed by the GCA system. The GCA sensor array (fg. ) conssts of a stable reference pont frame x the doman of movng object ponts x. The sensor observatons l, n the dam example fg. GPS-baselne observatons the total statons observatons, enable the permanent estmaton of the deformaton state vector y (t) n dependence of tme t. 2 GCA Deformaton Analyss Software Basc Concepts The deformaton analyss concept mplemented n the GCA software s due to a classcal deformaton analyss (Kä lber Jäger, 2; Feldmeth et. al, 24; Jä ger Bertges, 24). It s based on a strct network adjustment s realzed n three subsequent adjustment steps ( st, 2 nd 3 rd step). The montorng network s physcally realzed by an array of GPS/GNSS LPS sensors, whle the respectve deformaton network desgn has to be specfed n the ntalzaton step ( st step). The st step provdes the ntalzaton of the so-called reference or stable pont frame of the montorng network. As concerns GPS t holds, that ndependent of beng set up ether as a GPS/GNSS base staton or as a rover staton, any GPS/GNSS recever has to be specfed to be ether a (stable) reference pont or a (movng) object pont. So an optmum desgn of a GPS/GNSS montorng array - e.g. wth respect to short baselnes - s enabled. In the context wth an adjustment concept behnd all steps of the GCA deformaton analyss, the deformaton network desgn may be set up as a redundant (e.g. by usng two GPS/GNSS reference statons or addtonally LPS sensors (total statons; automatc levellng) or as a non-redundant confguraton. The ntalzaton, namely the st adjustment step, s based on a least squares (L2-norm) free network adjustment of the GPS/GNSS baselne LPS data wth respect to a user-defned startng epoch, s robustfed wth respect to gross errors by an automatc teratve data snoopng ncludng a stepwse varance component estmaton. By the am of realzng a classcal deformaton analyss n a permanent onlne mode, ths st step has to precede the deformaton montorng, as t provdes the network datum x (fg. ) for the permanent georeferencng of the object ponts x (fg. ) the deformaton analyss, whch run parallel n the followng 2 nd 3 rd adjustment step. The 2 nd step performed by the GCA software s agan based on the above mentoned GKA baselne LPS data s runnng completely automatcally durng the onlne montorng. Any onlne montorng project can however also be processed n a post-processng mode. The 2 nd step comprses the permanent L2- norm adjustment of the GPS/GNSS baselnes LPS data (dstances, zenth angles, drectons, heght dfferences) the mathematcal model provdes the georeferencng of the 3D objectpont poston tme seres x (t ). The reference frame x (fg. ) s consttuted by the stable reference ponts, whle both the coordnates the covarance matrx of the reference ponts - as 2

3 the result of the st step - are consdered n the mathematcal model. Based on a L2-norm adjustment ncludng automatc data-snoopng, the 2 nd step works automatcally, both for redundant or for non-redundant GPS/GNSS LPS array confguratons. The 3 rd step, the deformaton analyss tself, mplemented n the GCA software, deals wth the estmaton of the parameters of dfferent socalled deformaton functons runs parallel onlne to the 2 nd step. The parameter estmaton s related to the results of the 2 nd step, namely the 3D object-pont poston tme seres x the stochastc model. The 2 nd the 3 rd step are hled onlne as seamless consecutve adjustment processes. The estmaton of respectve deformaton functons parameters can be performed n the 3 rd step onlne ether as a L2-norm estmaton, (5b) or a obust L-norm estmaton (5c), or a obust M-Estmaton (5d). The estmaton prncple can be chosen by the GCA software user. The followng object-pont related deformaton functons respectve parameter estmaton algorthms are avalable n the onlne montorng mode of the GCA software: Movng average ncludng the detecton of crtcal dsplacements Automatc dsplacement estmaton ((8a), (8b), fg. 4) between dfferent epochs (each epoch s ndvdually specfed by an nterval length, e.g. 3 hours) o st epoch = Intalzaton ( st step) 2 nd epoch s movng n a defned cycle o st epoch = Fxed by user defnton 2 nd epoch s movng n defned cycle o st epoch = Dynamcally movng 2 nd epoch s movng n defned cycle Kalman-Flterng (9a), (9b) wth the state vector of three-dmensonal o dsplacements u (t), o veloctes u& (t) o acceleratons u&(t & ). Fg. 2 Example of a GPS recever telemetrc equpment wthn a GCA sensor array n case a slope montorng n open cast mnng at WE Power AG (see, tab. ) usng the GCA system. The deformaton functons the respectve parameters descrbed above can be referred ether to crtcal values or to sgnfcant changes, e.g. n the dsplacements u(t) ((7a), (7b); (8a), (8b), (9a), (9b); fg. 4; fg. 5), so that an automatc alarm can be sounded accordng to the user-defned prortes alarm modes (emal, SMS, fax, etc). The above onlne deformaton functons can also be used n a near-onlne or a post-processng mode (e.g. n a daly processng of the data). In the near-onlne post-processng of the 3 rd step the complete spectrum of the above mentoned onlne deformaton functons s agan avalable, addtonally the deformaton functons of a Polynomal based trend-estmaton, a Leap detecton the estmaton of Dsplacements between two epochs defned by an ndvdual nterval length (e.g. one day). 3

4 Here the estmaton prncples are besdes L2- norm the robust L-norm extended wth respect to the robust Huber-estmator (Bckel, 975; Jä ger et al. 25]. 3 Mathematcal Models mplemented n the GCA software 3. Adjustment steps 2 eference Pont Intalsaton Georeferencng of the bject Ponts In the st n the 2 nd step all GNSS LPS observatons l, whch may accordng to the sensor desgn (fg. ) ether take place between the reference ponts x or between the object ponts x or between reference ponts x object ponts x are ncluded n an onlne geodetc network adjustment. The observatons l - lke shown n fg. at the example of the GNSS baselne vectors /or the LPS observatons of total-statons (dstances, zenth angles dstances) - are collected provded by the GKA data nterface together wth ther respectve covarance matrces C. In general the relaton l l = l(y) () between the sensor observatons l the state vector y of the deformaton montorng network s nonlnear, the so-called functonal model () has to be lnearsed by ntroducng approxmate parameters y. Ths s done automatcally by the GCA software. The observatons l () are collected at a trackng rate t (e.g. t = sec for GPS (fg. 2)), whch may be synchronc or dfferent for the dfferent sensor types n the montorng array (fg. ). The defnton of dscrete perods or epochs for the descretsaton of the object pont movements s referrng to the so-called samplng nterval T, t must hold t T (2a) The lower upper border of the dscrete samplng nterval T(t ), whch refers to the epoch t has a duraton of T, reads: (t ) = [t T,t + T ] (2b) T 2 2 Accordng to (2b) the tme dcretsaton of the object pont s dsplacements s done n subsequent ntervals (2b) of duraton T. So all observatons l wthn the tme borders of the samplng nterval T(t ) (2b) refer to a constant state vector t ) x ( = x of the object pont coordnates at epoch t. bservaton sets l l j belongng to two general dfferent epochs t accordngly refer to two dfferent sets of coordnates x x j t j, whch are be set up n the tme nvarant coordnate frame x of the reference ponts (fg. ). For two general epochs t t j we get after the lnearzaton of () the followng system of an n general over-determned socalled system of observaton equatons: ( l l ( y )) + v = = A dx + A dx + dxj C l (3a) ( l j l j( y )) + v j = = Aj dxj + dx + Aj dx (3b) j C lj Wth A( y ) we ntroduce the type of the socalled desgn matrces, whch relate to the frst dervatves of the observatons l wth respect to the unknown parameters y. Wth v v j we descrbe the vectors of observaton correctons of the observaton vectors l l. Upon demng the stablty constrant j x = x = x for the reference ponts (fg. ), we obtan as the basc state vector of the deformaton process modelng y n the st 2 nd step for two general epochs t t j readng T dy = (dx dx (t ), d x (t j)) y = y + dy. j (4a) (4b) 4

5 Accordng to (3a), (3b) (4a), (4b) the mathematcal model the basc deformaton process related state vector y can easly be extended to any number of m montorng epochs. 3.2 Least Squares Adjustment obust M- Estmaton The so-called M-estmaton (Jä ger et al., 25) appled to n observatons l k (k=,n) n all m montorng epochs reads n ρ( v k ) = k= n = ρ( ( C 2 dˆ 2 l A) k y ( Cl ( l l( y ))) k ) = k= n ρ( Ak dˆ y ( l l( y )) k ) = Mn dˆ y (5a) k= leads to the the state vector y (4a), (4b) by mnmzng the total sum of the so-called loss functon ρ ( v k ) of the stardzed resduals v k. Wth A l we ntroduce the so-called homogenzed desgn matrx homogenzed observatons, respectvely. The algorthmc soluton of (5a) the determnaton of the estmaton ŷ the covarance C ŷ are descrbed n Jä ger et. al (25). Dependng on the type of the loss-functon ρ ( v k ) the estmaton of the parameters y n the st, 2 nd 3 rd GCA-adjustment step s ether due to a least squares (L2-Norm), a L- Norm or a Huber estmaton. The respectve loss functons read (Jä ger et al. 25, Holl 975, Bckel 975): Least squares estmaton (L2-norm) 2 ρ ( v ) = v 2 (5b) The loss functon ρ ( v k ) (5b) s optmal for normal dstrbuted observaton errors (5c) (5d) are robust aganst gross observaton errors l k (Bckel 975, Jä ger et al. 25). The st adjustment step (ntalzaton) s based on a L2-norm (5b) s robustfed by the procedure of teratve datasnoopng. The st step provdes the reference pont frame nformaton for all the subsequent montorng steps. The steps 2 3 are runnng parallel. The essental result of the ntalzaton s the nformaton about the reference pont frame x (fg. ), whch s completely represented by adjusted coordnates x the covarance matrx C x. Both are (5a) stored n the GCA project database. The mathematcal model of the 2 nd adjustement step s also based on a L2-norm estmaton (5c) teratve datasnoopng provdes the tme seres x t ) of the object ponts the covarance matrces C x (t ) as x t ) C t ) (6a,b) x Accordng to (3a, (3b) the tme seres x ) (6a) (see fg. 3) are georeferenced n the reference pont frame x. In order to ncrease essentally the real-tme performance of the 2 nd step adjustment the coordnates x of the reference ponts resultng of the ntalzaton are held fx on settng d x =. The covarance matrx Cx s however taken nto account for the computaton of the covarance matrces C t ) (6b) of the x object pont tme seres x t ). The raw object pont dsplacements t are resultng by defnng a dscrete reference epoch t, we have obust L-norm estmaton ρ ( v ) = v 2 Weak robust Huber-Estmaton 2 2 v v k ρ( v ) = v v > k (5c) (5d) u t ) = x (t ) x (t ) C t ) (7a,b) ( u u The covarance matrces C t ) (7b) are resultng by applyng the so-called law of error propagaton to (7a). 3.3 nlne Dsplacement Estmatons 5

6 The mathematcal model of the object-pont related deformaton functons (chap. 2.) the respectve parameter estmaton algorthms n the 3 rd step of the GCA deformaton analyss are referrng to the object ponts x t ) (6a) u t ) (7a) respectvely. The object ponts x t ) (6a) u t ) (7a) are used as observatons l ) together wth the stochastcal models C t ) (6b) C t ) (7b), respectvely. x u Fg. 3 GCA object-pont tme seres x ) as result of the 2 nd adjustment step of the GCA-software. The thck lnes show the smoothng by a robust movng average estmaton applyng the M-estmaton (5c). The dfferent M-estmaton prncples (5b), (5c) (5d) can be selected arbtrarly be the user n the G- CA settngs dalogs for the deformaton functon estmatons of the 3 rd step (see e.g. fg 4). The functonal model of the GCA object pont dsplacement estmaton u (t) (Jä ger und Bertges, 24) at a tme t wth respect to the reference tme t state vector y (t) reads: l v E t t + = l t v t E2 x E2 u(t) (8a) T y ( t) = ( xo, u(t)) (8b) observatons groups l t l t (8a) taken from the tme seres vector x ) (6a) provde n general redundancy wth respect to the state vector y (8b) of the dsplacement model (8a) wth only 6 parameters for each object pont x. The sx parameters y(t) are the 3-dmensonal poston x at the reference tme t the 3-dmensonal dsplacement u(t) at the estmaton epoch tme t. The matrces E E 2 are column matrces composed of (3 x 3)-unt matrces for each three-dmensonal observaton n the respectve group. Fg. 4 shows the GCA-software settngs dalog for the onlne dsplacement estmaton accordng to the mathematcal model (8a) (8b) n the deformaton analyss (3 rd step). The dfferent settngs concern the choce of the object ponts, the epoch defnton for the dsplacement estmaton u (t), the settngs for adjustment statstcal testng, the settngs for an automatc alert. The reference tme t s agan defned wth respect to an extended tme nterval t (fg. 4, left) for the observatons taken from the tme seres x ) (6a). The same holds for the tme t referrng also to an extended nterval t (fg. 5, rght). Accordngly the two t 6

7 Fg. 4. GCA onlne deformaton (3 rd step). Settngs for the onlne dsplacement estmaton alertng. 3.4 Kalman-Flterng as General M-Estmaton The GCA Kalman-Flterng (Kä lber Jäger 2, Feldmeth et al. 24, Kä lber et al. 22) as a second example for the deformaton parameter estmaton n the 3 rd step s related to the followng socalled transton equaton (9a,b), to the state vector y (9c) readng: y ( t) = T y(t t), (9a) u(t) I y(t) = u& (t) = u&& (t) wth [ t] I 2 t u(t t) 2 [ t] u& (t t) I u&& (t t) (9b) T y ( t) = ( u, u&, u& ). (9c) The state vector y(t) of the GCA-Kalman-Flterng comprses the ndvdual three-dmensonal dsplacement u (t), velocty u& (t) acceleraton u&(t & ) of the object ponts between subsequent tme ntervals t. A Kalman-Flterng a tme t s equvalent to the common adjustment of the predcton of the state vector y (t) (9a,b,c) the state vector related observatons l(y(t)) at tme t. So the system of observaton equatons of a Kalman-Flterng generally reads: y ( t) + v y = yˆ(t) C y (t ) (a) l ( t) + vl = l(ŷ(t)) = A dˆ y + l( y(t)) C l. (b) The covarance matrx C y (t ) (a) of the predcton s receved by applyng the law of error propagaton to the system transton equaton (9a,b). In case of GCA the observatons l(t) for the Kalman-Flterng are taken from the object pont tme seres (2 nd adjustment step) relate only to the object pont dsplacements u ) (7a). So the desgn matrx A (b) of the GCA observatons component s flled wth zero elements at the poston of the velocty acceleraton parameters wthn ŷ (t). The lnearzaton n (b) s done wth respect to the predton y (t) (9a,b). The generalzed M-estmaton of the parameters ŷ(t) of the Kalman-Flter model (a,b) can be computed teratvely as: ˆ y(t) = y(t) + K ( l(t) l( y(t)), wth (a) 2 2 K = ( Cy Wy Cy + AWl A) AWl. (b) (González 25). Agan the above homogenzton (5a) s used n (a,b). The teratve Kalman matrx K has to be recomputed stepwse (j=j-th step). In the j-th step the dagonal wegth-matrces W y Wl wthn K are set up a weghtng functon related to the argument of the homogenzed correctons v y, v l, of the parameter the observaton component (b,c). The specfc weghtng functon w(v ) of any M-estmator s strc- 7

8 tly based ts loss functon ρ ( v ) (5b,c,d). It reads (Bckel 975, Holl 977, Jä ger et al. 25): ρ(v ) / v ψ(v ) w = w(v ) = =. (c) v v The frst dervatve ψ ( v ) of the loss functon s the socalled nfluence functon. In case of an L2-norm (least squares) Kalman-Flter (5b) t holds that w =.. So the general teratve M-estmaton computaton (a,b) s (only) n case of the classcal least squares (L2 norm) Kalman flter already fnshed n one step j=. Lke the onlne dsplacement estmaton (8a,b), wth the settngs shown n fg. 4, rght, the above GCA-Kalman-Flterng can also be performed by settng ether a least squares estmaton (5b) or a robust L-norm estmaton (5c) prncple by the user. 4 Further Features of the GCA-Software 4. Congruency Testng Detecton of Instable eferences Ponts A specal feature of the GCA deformaton analyss software conssts n the automatc procedure of a statstcally strct testng of the congruency of the plan heght component of a GPS-array. In the context of settng up a classcal deformaton network, the stable pont test procedure s appled to detect nstable reference ponts (Kä lber Jäger, 2). In ths way dstortons of the object-ponts or better pseudo deformatons, whch would n case of undetected nstable reference ponts occur of the object space, are excluded of the deformaton process modellng. Wth respect to a maxmum senstvty the detecton of nstable reference ponts between dfferent epochs s performed as a :(n-m) process. Ths means, that - n analogy to the classcal observaton-related teratve data-snoopng - a sgnfcant 3D dsplacement of each reference pont s tested n the m th step relatve to (n-m) stable ponts, startng wth m=. The teratve stable pont testng s agan accompaned robustfed, respectvely, by an teratve data snoopng concernng the GPS/GNSS baselne observatons (GKA fles) by a varancecomponent estmaton. 4.2 Deformaton Integrty Montorng of eference Staton Networks The GCA software the mplemented stable pont testng algorthm (chap. 4.) can be appled for the statstcally strct detecton of possble movements of statons n GPS/GNSS postonng servce such as SA- PS ( ascos. ( Ths feature of the GCA system s called deformaton ntegrty montorng of reference staton network, s appled n dfferent states n the German SAPS network. 5 Present Developments of the GCA- Software The present development of the GCA software s dealng wth the mplementaton of dfferent so-called GPS/GNSS-baselne processng engnes. Ths knd of GPS-processng packages wll enable the GCA software to work n a near-onlne mode wth respect to the ntegraton of a GPS raw data processng (code phase measurements), whch s based on I- NEX data (Kä lber Jäger ). ne applcaton of the GPS/GNSSraw data processng capacty s the deformaton ntegrty montorng of reference staton networks (chap. 4.2). A thrd topc s concernng the further development of the GCA software for a Montorng n the hgher frequency doman (e.g. Hz for the montorng a structural vbratons). Further developments n the doman of deformaton analyss theory are dealng wth System analyss related deformaton process modelng a respectve sensor system parameter ntegratng modelng (Jä ger Bertges 24). Approprate approaches both for statc dynamc process modelng system parameter estmaton are provded by fnte element models (FEM) of structures (Jä ger Bertges, 24). Here the dsplacement-, velocty- acceleraton-feld, whch are resultng from the GCA software n the 2 nd 3 rd step, as well as data from other local sensors (e.g. stran- or tltmeters), can be used as addtonal observaton sources n a FEM approach (Kä lber et al. 2, Kälber und Jä ger 2, Jä ger und Bertges 24). 6 Examples - GCA-Software Projects Tab. above gves an overvew over the GCA system users at dfferent enterprses research nsttutons all over the world. eports of the GCA system users downloads can be found at the GCA homepage (Kä lber Jäger ). The fg.3 shows the tme seres vsualsaton as result of the above mentoned 2 nd adjustment step mplyng the georeferencng of the object ponts x ) n the datum of the stable ponts x together wth the parallel runnng movng average estmator (3 rd adjustment step). The example fg. 3 shows the vertcal the horzontal dsplacements of a GCA montorng of an underground coal mnng n a depth of 8 m. 8

9 Fg.5 Vsualzaton of the GCA dsplacement estmaton (3 rd step). Thck horzontal lne left shows the estmaton of x (8a), (8b) by a number of observatons x ) belongng to the reference tme t. The thck horzontal lne rght shows the estmated poston x ( t) = xo + u(t), the thck arrow shows the estmaton vertcal dsplacement u (t). The fg. 5 shows the vsualzaton of the result of a dsplacement estmaton u(t) between a reference epoch t (left) wth a fnte observaton nterval, the estmaton epoch t (rght). The fg. 5 clearly reveals the benefts of an onlne montorng, where - compared to a classcal dscrete montorng a large number of sngle postons x t ) contrbute to the estmaton of the state vector T y ( t) = ( x, u(t (8b), whle at the same tme a robust o )) estmaton (5c), (5d) s able to prevent the nfluence of gross errors n the observatons l(t) gven by the tme seres x t ) on the deformaton parameters y(t). Table GCA-system software users at prvate state nsttutons at unverstes research centers Prvate companes State Companes Deutsche Stenkohle AG (DSK), Germany henbraun Power AG (WE) at Hambach, Garzweler, Elsdorf, Germany GeoInternatonal Manz, Germany ö ssng Mnes, Namba, Afrca Vorarlberger Illwerke, Austra Morla Mnes, Mal, Afrca DMT, Germany SwssPhoto Group, Swtzerl Vattenfall Europe, Germany Lesvermessungsamt des Saarles DrBertges Vermessungstechnk, Germany Sudsdence horzontal deformatons. Coal mnng Slopes. pen cast coal-mnng 3D lslde montorng Slope-montorng. Uranum-mnng Dam-montorng Slope-montorng. Gold-mnng 3D Montorng n mnng Longterm 3D montorng Gotthard ralway tunnel Slope, uplft, subsdence montorng. pen cast mnng SAPS GNSS reference staton network montorng Dfferent Projects. GCA cooperaton partner GeoNav-Trmble Dfferent Projects. GCA cooperaton partner Palabora Mnng, South Slope montorng, Copper Afrca mnng Unverstes esearch Insttutons Unverstä t Hannover, Germany Unversty of Federal Forces Munch, Germany Unverstä t Innsbruck, Austra Unversty of Appled Scences (FH), Karlsruhe Fg. 6 shows the locaton of the two object pont GPS sensors durng the Kops dam (Austra) montorng as an example of a GCA-nstallaton amng at the montorng deformaton process modelng of buldngs geotechncal structures, respectvely. The Fg. 7 above shows one of the 5 GPS sensors of the Gotthard tunnel montorng GPS array n the hgh Alps of Swtzerl. Startng n 22, the GCA-system wll be nstalled there for at least 2 years, namely durng the complete duraton of the constructon of the 57 km long Gotthard ralway tunnel. Fg. 6 GCA nstallaton at Kops dam, Austra. 9

10 lyss based approaches, as requred by the nterests of geodessts of other dscplnes such as geodynamcs, geotechncs cvl engneerng. eferences Fg. 7 GPS-recever on pllar wth solar panel energy supply as part of the GCA array for the montorng of the Gotthard ralway tunnel constructon (22-24). Conclusons The contrbuton treats the GNSS/GPS/LPS-based nlne Control Alarm system (GCA). The GCAsoftware components set up an array of GNSS- /or LPS-sensors, whch are equped wth a telemetrc, GSM, LAN or nternet communcaton. GCA can be used for a contnuous montorng of natural hazards (lsldes, volcanos, water level), for the montorng of geotechncal structures (mnng, tunnelng) buldngs (constructons, dams). The deformaton network ponts may be occuped both n a permanently mode as well as ntermttently. All onlne computaton steps can be performed also n a post-processng or a near-onlne mode. The GCA-deformatonanalyss-software s responsble for a further processng of the GPS/LPS data n a three steps sequental adjustment procedure, whch models n total an onlne classcal three-dmensonal deformaton network. The network adjustment concept behnd the GCA-deformatonanalyss-software provdes a unque georefercencng of the GNSS/LPS-occuped object pont postons n the coordnate frame of the reference ponts. The onlne deformaton analyss of the object-pont can be set up as flexble user-defned dsplacement estmaton or by a Kalman flter (dsplacements, veloctes acceleratons). Both least squares robust estmaton technques are appled, so that a relable settng of an alarm s enabled, n case that a crtcal state s reached proved by statstcal testng. The worldwde use of the GCA system n dfferent domans of envronmental montorng research s documented shown by examples. The evaluaton of contnuous tme seres of the objects dsplacement feld, provded by GCA, opens new perspectves n deformaton analyss model calbraton. Ths concerns the transton from the classcal geometrc deformaton analyss to so-called system ana- Bckel, P. (975): ne-step Huber estmates n the lnear model. Journal of the Amercan Statstcal Assocaton (7) Borchers, S. und. Heer (22): Bauwerksüberwachung mt GKA (GPS-basertes nlne Kontroll- und Alarmsystem) an der Schleuse Uelzen I. Schrftenrehe des DVW, B 44, Konrad Wttwer Verlag. ISBN , ISSN , S Bulowsk, T. (2): Kontnuerlche Ü berwachung von Tagebaubö schungen mt dem System GCA. 43. Wssenschaftlche Tagung der DMV (Deutsche Markscheder Verengung), Sept., Trer. DMV Mttelungen, 2. Feldmeth, I., Jä ger,. und. Zschnsky (24): GPS-based nlne Control Alarmsystem GCA Lestungsstards am Ensatzbespel Staumauer Kops (Vorarlberger Illwerke AG, Ö sterrech). Wasserwrtschaft - Zetschrft für Wasser und Umwelt, Heft -2, 24. Veweg Verlag, Stuttgart, ISSN Holl, P.W. (977): obust egresson usng teratvely reweghted Least Squares. Commun. Statst.-Theor. Meth. A6(9), S González, F. (25): Improvement, edesgn, C++-based Implementaton Testng of the GCA-Kalmanflterng Modules. Masterthess m Masterstudengang Geomatcs der Fachhochschule Karlsruhe. Jä ger,.; Müller, T.; Saler, H.. Schwä ble (25): Klasssche und robuste Ausglechungsverfahren - En Letfaden für Ausbldung und Praxs von Geodä ten und Geonformatkern. ISBN Wchmann Verlag. Jä ger,. und M. Bertges (24): Integrerte Modell bldung zum permanenten Montorng von Bauwerken und geotechnschen Anlagen. Betrag zum 6. DVW-Fortbldungssemnar, 27./28. September 24, Bauhaus-Unverstä t Wemar. DVW-Schrftenrehe, B 46/24. ISBN S. -4. Kä lber, S.. Jäger (999-25): GCA-Homepage. Kä lber, S.; Jäger, ; Schwä ble,.: Hemberg, F. K. Kast (2): GPS-based nlne Control Alarm System (GCA). eport presented to the 2. ICLD- Congress, 2, Pekng. Int. Commsson on Large Dams, Pars. Kä lber, S. und. Jäger (2): GPS-based nlne Control Alarm System (GCA). Proceedngs th FIG Internat. Symposum on Deformaton Measurements. range, Calfornen, USA, March. CDM. Korttke, N. und G. Palte (2): eal-tme-montorng von bergbaubedngten Gebä udebewegungen mt GPS. Schrftenrehe des DVW, B 43, Konrad Wttwer Verlag. ISBN , ISSN , S Lauterbach, M. und E. Krauter (22): Satelltengestütztes Montorng ener Großrutschung m Berech enes Autobahndammes be Lstuhl/Pfalz. Messtechnk Geotechnk, Nr. 25, 22. Schä fer, W. (24): GPS-gestützte 3D-Permanent-Ü berwachung bewegungsempfndlcher Bergschadensobjekte. Zetschrft Markschedewesen.