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1

STEPPING – smartphone-based portable pedestrian indoor navigation

Lukianto Ch., Sternberg H.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2011

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Vol. 22

311--323

EN

Many current smartphones are fitted with GPS receivers, which, in combination with a map application form a pedestrian navigation system for outdoor purposes. However, once an area with insufficient satellite signal coverage is entered, these navigation systems cease to function. For indoor positioning, there are already several solutions available which are usually based on measured distances to reference points. These solutions can achieve resolutions as low as the sub-millimetre range depending on the complexity of the set-up. STEPPING project, developed at HCU Hamburg - Germany aims at designing an indoor navigation system consisting of a small inertial navigation system and a new, robust sensor fusion algorithm running on a current smartphone. As this system is theoretically able to integrate any available positioning method, it is independent of a particular method and can thus be realized on a smartphone without affecting user mobility. Potential applications include -- but are not limited to: Large trade fairs, airports, parking decks and shopping malls, as well as ambient assisted living scenarios

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Low cost attitude and heading sensors in terrestrial photogrammetry – calibration and testing

Kolecki J., Kuras P.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2011

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Vol. 22

249--260

EN

Most of the contemporary terrestrial mobile mapping systems (MMSs) use tactical or navigation grade inertial measurement units (IMU) to determine the approximated angular exterior orientation (EO) elements of images. Navigation grade IMUs, usually integrated with GNSS receivers, are also used to determine the projection center coordinates. Recent researches show that using also a low-cost attitude and heading reference system (AHRS) or a low-cost IMU, satisfies the demands of certain photogrammetric applications. Our researches aim to evaluate the accuracy of low-cost devices suitable for constructing small, low-cost photogrammetric MMS. During our research two low-cost devices, providing information about image attitude and heading, were tested. The first one is the calibrated Ricoh G700SE GPS camera with an electronic compass and a level indicator. The second device is the Xsens MTi AHRS unit, comprising 3 MEMS (micro-electromechanical systems) gyros, 3 MEMS accelerometers and 3 magnetometers. For the testing purposes the AHRS was combined with the calibrated Nikon D80 SLR camera. The 3D AHRS magnetometer calibration was carried out using the manufacturer's software to compensate for the soft and hard iron effects. The images of three test fields were taken. The images of the first test field with signalized control points were used to determine the boresight rotation matrix of the AHRS. The bundle adjustment was solved separately for each camera and each test field to determine the true (reference) angular exterior orientation parameters. The differences between measured and calculated angles allowed to evaluate the accuracy of the measured angles. The tests results for the GPS camera show high residuals of measured azimuths, however its level indicator allows camera levelling with subdegree accuracy. The results obtained for the low-cost AHRS unit were significantly better, however over 2° residuals for yaw angle were also observed. The results prove the usefulness of the AHRS for constructing a small, hand-held MMS, whereas GPS camera azimuth measurements can be treated rather as a rough approximations in the photogrammetric network adjustment.

3

Errors-in-variables for mobile mapping algorithms in the presence of outliers

Schaffrin B., Uzun S.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2011

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Vol. 22

377--387

EN

A few years ago, Schaffrin and Iz (2008) generalized the traditional Kalman filter in such a way that it could handle observation equations with errors-in-variables. This approach led to what has since become known as Total Kalman Filtering (TKF). A drawback, however, was that the usual “data snooping” techniques were no longer applicable in the same manner. Therefore, in the presence of outliers, new search techniques need to be devised in order to accommodate for those errors-in-variables with non-zero expectations. In this contribution, an attempt will be described to prepare a suitable algorithm for this purpose in the context of mobile mapping.

4

Assisting personal positioning in indoor environments using map matching

Attia M., Moussa A., Zhao X., El-Sheimy N.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2011

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Vol. 22

39--49

EN

Personal positioning is facing a huge challenge to maintain a reliable accuracy through all applications. Although in outdoor applications, several mobile navigation devices can provide acceptable positioning accuracy, the situation in indoor environment is not the same. Mobile navigation devices mainly contain a global positioning system (GPS) receiver and an inertial measurement unit (IMU). The main drawback in indoor navigation applications is the unavailability of the GNSS signals, which decreases the possibility of obtaining an accurate absolute position solution, as the inertial system (INS) solution will drift with time in the absence of external updates. Several alternatives were presented lately to update the inertial solution such as using Wi-Fi, UWB, RFID, several self-contained sensors, imaging aiding and spatial information aiding. In order to achieve accurate position solution, with low-cost and usable technique, an integrated mobile navigation system integrating GPS/IMU/Wi-Fi and map-matching was developed. The developed system uses the prior knowledge of the indoor geometrical and topological information, as a threshold for the navigation solution, forcing the provided solution to be mostly on the right track. The geometrical and topological information for the building was used to build the geospatial data model. The use of this model was performed by developing a map matching algorithm which uses the geometrical and topological characteristics of the building to locate the user position on the building map. This algorithm was developed based on the geospatial information of the Engineering building, University of Calgary, where the field test occurred. The map-matching algorithm was evaluated by processing and comparing two separate navigation solutions through the study area, one using only the GPS/IMU/Wi-Fi system, and second solution was assisted with the map-matching algorithm which shows significant enhancement in the position solution for the indoor trajectory.

5

Precyzja i niezawodność pomiaru środków rzutów w rzeczywistych aerotriangulacjach

Ziobro J.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2007

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Vol. 17b

841--847

PL

Celem badan było określenie precyzji pomiaru środków rzutów uzyskiwanej w rzeczywistych blokach. Drugim celem badan było określenie niezawodności tej grupy pomiarów w aerotriangulacjach dla trzech skal zdjęć lotniczych. Badania oparto na ponownym opracowaniu danych z bloków produkcyjnych przy rygorystycznym przestrzeganiu warunków poprawności wyrównania. Wyrównania poprzedziło przedwyrównawcze wykrywanie błędów grubych i złego podziału pomiarów na profile GPS metoda opracowana przez autora artykułu. Wyniki produkcyjne pochodziły z różnych systemów pomiarowych oraz programów wyrównania i były obarczone szeregiem niedoskonałości dotyczących modelu funkcjonalnego i statystycznego, których ogólna przyczyna były stosowane technologie. Do testowania wybrano 25 bloków w trzech, często stosowanych w Polsce skalach zdjęć lotniczych: 1:13 000, 1:19 000 oraz 1:26 000. Druga istotna cecha tych bloków było występowanie pomiaru środków rzutów, przeciętnie dla 90% zdjęć w bloku. Liczba zdjęć w blokach wynosiła od 136 do 3402, a łączna liczba zdjęć we wszystkich blokach wyniosła około 30 tys. . Przeciętny błąd średni a priori współrzędnej środka rzutów otrzymany z 25 wyrównań wyniósł 10.7 cm. Wartość ta może być stosowana w symulacjach dla optymalizacji aerotriangulacji. Analiza globalnej niezawodności wewnętrznej pomiaru środków rzutów dla poszczególnych skal pokazała, _e w blokach o skali zdjęć 1:13 000 pomiary te miały przeciętnie lokalna nadliczbowość: 0.50 dla X, 0.48 dla Y i 0.75 dla Z. Można wiec powiedzieć, że niezawodność pomiaru środków rzutów w tych aerotriangulacjach była dobra. Dla tych bloków przeciętne, średnie kwadratowe poprawki wyrównawcze, do wszystkich trzech współrzędnych środka rzutów, stanowiły około 76% przeciętnego błędu średniego a priori. Dla skal 1:19 000 i 1:26 000, w 9 na 15 bloków, przeciętna lokalna nadliczbowość współrzędnych poziomych środków rzutów była mniejsza od 0.25. Dobry poziom niezawodności uzyskano tylko dla jednego z bloków. Przeciętna wartość średniej kwadratowej poprawki do współrzędnych poziomych stanowiła tylko około 56% przeciętnego błędu średniego a priori.

EN

The aim of this study was to determine the precision of GPS-coordinates of projection centres obtained in real blocks. Another goal of the work was to estimate the reliability of this group of measurements in aerial triangulations for three scales of aerial photographs. The study was based on renewed data preparation from production blocks, strictly obeying conditions of correctness of adjustment. The adjustment was preceded by the pre-adjustment detection of gross errors and bad assignment of measurements into GPS profiles, using a method developed by the author. Production results were derived from various measurement systems and adjustment software; they were characterized by numerous imperfections concerning functional and statistical model, generally resulting from the applied technologies. A set of 25 blocks was selected for testing, including three scales of aerial photographs: 1:13 000, 1:19 000 and 1:26 000, most frequently used in Poland. The presence of the projection centre measurements (on the average for 90% of photographs in the block) was the second important feature of selected blocks. The number of photographs in one block varied from 136 to 3402, and the total number of photographs in all blocks was about 30 000. A priori standard deviation of GPS-coordinates, obtained from 25 adjustments, reach 10.7 cm on the average. This value can be used in simulations for optimisation of aerial triangulation. Analysis of global internal reliability of GPS-coordinate for particular scales revealed that, in blocks of photographs at scale 1:13 000, the average redundancy component reached 0.50 for X, 0.48 for Y and 0.75 for Z coordinate. Therefore, it can be concluded that the reliability of GPS-coordinates of projection centres in these aerial triangulations was good. For these blocks, RMS residual of GPScoordinates reached 76 % of the a priori standard deviation, on the average. For scales 1:19 000 and 1:26 000, in 9 out of 15 blocks the global redundancy component of horizontal GPS-coordinates was lower than 0.25. Good level of reliability was obtained only for one block. For these blocks RMS residual of horizontal GPS-coordinates reached 56 % of the a priori standard deviation, on the average.

6

Kierunki rozwoju systemów zintegrowanych GPS/INS

Głogowski P., Mozgiel M.

Prace Wydziału Nawigacyjnego Akademii Morskiej w Gdyni

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2004

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Z. 15, cz. I

292-298

PL

W artykule sformułowano kryteria, warunkujące rozwój systemów zintegrowanych GPS/INS pod kątem ekonomicznym i technologicznym. Omówione zostały kierunki rozwoju systemów zintegrowanych GPS/INS. W dalszej części artykułu zaprezentowano metody integracji systemów nawigacji inercyjnej z GPS, ze szczególnym uwzględnieniem inteligentnych układów sensorowych. Ponadto omówiono elementy determinujące wybór konfiguracji modelu systemu zintegrowanego w aspekcie bezpieczeństwa żeglugi.