For mapping of building interiors various 2D and 3D indoor surveying systems are available today. These systems essentially differ from each other by price and accuracy as well as by the effort required for fieldwork and post-processing. The Laboratory for Photogrammetry & Laser Scanning of HafenCity University (HCU) Hamburg has developed, as part of an industrial project, a lowcost indoor mapping system, which enables systematic inventory mapping of interior facilities with low staffing requirements and reduced, measurable expenditure of time and effort. The modelling and evaluation of the recorded data take place later in the office. The indoor mapping system of HCU Hamburg consists of the following components: laser range finder, panorama head (pan-tilt-unit), single-board computer (Raspberry Pi) with digital camera and battery power supply. The camera is pre-calibrated in a photogrammetric test field under laboratory conditions. However, remaining systematic image errors are corrected simultaneously within the generation of the panorama image. Due to cost reasons the camera and laser range finder are not coaxially arranged on the panorama head. Therefore, eccentricity and alignment of the laser range finder against the camera must be determined in a system calibration. For the verification of the system accuracy and the system calibration, the laser points were determined from measurements with total stations. The differences to the reference were 4-5mm for individual coordinates.

Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.

This paper addresses the topic of semi-automatic object extraction for GIS data capture. It includes novel algorithms and conceptual strategies, together with performed experiments, encountered problems and adopted solutions. In particular, we present an algorithm and obtained results for semi-automatic extraction of road networks from SPOT imagery using wavelet-transformed images and cost functions expressing local gray value variations and global continuity constraints. For larger scale images and for various object types, we present our technique of least squares template matching for edge extraction, which uses local gray value variations to precisely identify edge locations. Finally, we propose a global approach for semi-automatic object outline detection, whereby least squares matching provides the mathematical foundation, while global continuity is enforced through the introduction of object-type-dependent shape constraints.

For a reasonable financial amount, today no CCD-arrays are available with an information content close to traditional photogrammetric aerial cameras. By this reason the Digital Mapping Camera DMC of Z/I Imaging is using a combination of 4 CCD-arrays, each with app. 4000 x 7000 pixels. As CCD-arrays cannot be fitted together without gaps, the 4 individual optics of a DMC camera are combined in a convergent arrangement. For easy handling, the images of the individual optics have to be arranged together to a single virtual image, corresponding to the geometry of one single perspective camera. In spite of a very stable mounting, small movements of one optic against the other cannot be avoided. By this reason, the sub-images are transformed together based on tie points in the overlapping areas by bundle adjustment solution. This is resulting in a sub-pixel accuracy of the virtual image based on the availability of a precise determination of the interior orientation of the single camera heads.

Using high resolution optical satellite imagery for automatic DTM generation the validation of the digital terrain model becomes an issue. This problem is easily to overcome if a DTM already exists, as given in various European countries. For the validation of the MOMS02-P camera experiment the outcome of the data take M2P083C of March 14, 1997 is compared with the archived DTM of the Bavarian state survey department. The reconstructed MOMS-DTM has a size of 50kmx178km, within an estimated overall accuracy of about 11.6m. Investigations have shown, that this figure can be broken down taking into account various landscape types. This is necessary to come close to the expected height accuracy of the MOMS02-P experiment, what should be in the order of 6-7m.

Airborne pushbroom systems for the direct acquisition of digital imagery enable the simultaneous capture of high quality 3D and multispectral information of a scene. The combination of geometric and radiometric information should improve tasks like DTM generation – usually solely based on stereo imagery – and landuse classification, which is traditionally restricted to the interpretation of spectral information. Within this paper these assumptions are confirmed utilizing datasets of the DPA (Digital Photogrammetric Assembly), a scanning airborne sensor which records simultaneously high spatial resolution stereo and multispectral image. Since the surface reconstruction and ortho image generation from airborne scanner imagery, which is a prerequisite for the proposed approach is different to standard procedures using full frame images, this process will be described in the first part of the paper. Afterwards the benefits of a combined evaluation of stereo and multispectral data will be demonstrated for two tasks, the generation of Digital Terrain Models and the landuse classification for thematic mapping.

Within the last years extensive tests were done to investigate the accuracy performance of integrated GPS/inertial systems for direct georeferencing in airborne photogrammetric environments. Based on commercially available high performance GPS/inertial systems direct georeferencing was shown to be a serious alternative to standard indirect image orientation using classical or GPS-supported aerial triangulation. Nonetheless, correct overall system calibration including the GPS/inertial component as well as the imaging sensor itself is the limiting factor in this approach. Since direct georeferencing without ground control relies on an extrapolation process only, remaining errors in the system calibration will significantly decrease the quality of object point determination. Therefore, special focus has to be laid on the overall system calibration procedure. Within this context the stability of system calibration over longer time periods and the influence of additional self-calibration on the calibration parameter estimation are of special interest. The investigations presented in this paper are based on test material from a real flight test, where as one part of a big project a calibration field was flown several times within a two month period using the same GPS/inertial-camera system installation. From this test data first statements on the long term stability of system calibration are feasible, which are important especially from a practical point of view when applying direct georeferencing in photogrammetric production processes.

Within the last five years extensive research was done using integrated GPS/inertial systems for the direct georeferencing of airborne sensors for high-end applications. Pushed by the development and practical use of digital sensor systems, originally started with laser scanner systems and followed by imaging multi-line pushbroom scanners, direct georeferencing offers the only way for an efficient sensor orientation process. Nonetheless, even for standard frame based camera systems, digital or analogue, the use of direct orientation measurements is useful in especially in – from a photogrammetric point of view – unfavourable applications like corridor surveys or single model orientation. In the ideal case using direct exterior orientation elements with sufficient accuracy image orientation without any ground control is possible. Within this paper the use of integrated systems in airborne environments is discussed, where the main emphasis is laid on the combination with standard analogue frame cameras. The empirical results of different well controlled test flights are used to illustrate the today's performance of direct georeferencing based on high-end integrated systems. Additionally, a combined GPS/inertial-AT or integrated sensor orientation approach is presented which allows the in-situ calibration of certain system parameters even without ground control and therefore provides highest flexibility to overcome the most limiting factor of direct georeferencing: uncorrected errors in the overall system calibration. Finally, the use of directly measured exterior orientations in model orientation and DEM generation is investigated.

This paper deals with investigations on the geometric reconstruction and sensor calibration of satellite–based optical imaging systems using linear arrays in pushbroom mode, like SPOT, IRS–1C and MOMS–2P/PRIRODA. The geometric model of the sensor is based on an extension of a SPOT model developed by V. Kratky. This geometric solution combines the principle of rigorous photogrammetric bundle formulation with additional constraints derived from known relations assuming an elliptic orbit. The attitude parameters are modelled by a simple polynomial model being linear or quadratic. Ephemeris data (orbital position and attitude data) are not necessary but are optional. The parameters of the interior orientation, e.g. focal length and principle point coordinates, are determined by self–calibration. The sensor model can be easily extended to process images from other high resolution imaging systems as they become available. The flexibility and very good accuracy of the solution will be demonstrated with MOMS–2P/PRIRODA imagery, since multiple scenes with overlapping images are available with a relatively high image resolution.

Within the paper the results of several studies will be presented, which have been carried out at ifp in order to evaluate the performance of digital airborne pushbroom cameras for photogrammetric data acquisition. In close cooperation with the respective system developers the DPA (Digital Photogrammetric Assembly) of DASA, the HRSC (High Resolution Stereo Camera) and the WAAC (Wide Angle Aircraft Camera), both of DLR have been tested. The aim of the paper is twofold. First the accuracy potential of the investigated systems is demonstrated. For that purpose the results of a photogrammetric point determination using imagery of the different systems collected over a well defined test field are presented. In the second part the photogrammetric processing chain covering the reconstruction of exterior orientation and point determination, but also tasks like DTM and ortho image generation will be compared for pushbroom and for full frame imagery. The discussion of theses differences will help to demonstrate the impact of applying pushbroom imagery during the standard photogrammetric evaluation process.

One crucial point during the application of direct georeferencing is the accuracy and reliability of directly measured orientation parameters using integrated GPS/inertial systems in an operational photogrammetric airborne environment. In order to investigate the potential of direct georeferencing for standard photogrammetric applications the accuracy of a commercially available GPS/inertial system (Applanix POS/DG 310) is evaluated. For that purpose a well controlled airborne test comparing the results from standard bundle adjustment and point determination by direct georeferencing is described. Within this test special focus is given on the quality of the GPS/inertial exterior orientation using several master stations with varying baseline length up to 380km. Additionally, the influence of variable image overlap on the resulting object coordinates is investigated. Although very consistent and high accuracy in object space is proved using direct georeferencing, the tests show the great importance of proper calibration between GPS/inertial and camera components. From this point of view, the integration of the GPS/inertial exterior orientations in a combined aerial triangulation provides the most flexible approach and is recommended for highest photogrammetric accuracy demands.

The determination of the exterior orientation parameters is an essential pre-requisite for the evaluation of any imagery from terrestrial, airborne or satellite based sensors. Normally, this georeferencing processing is solved indirectly by using a number of well known ground control points and their corresponding image coordinates. Using a mathematical model for the relation between image and object space the exterior orientations can be calculated and the local image coordinates are related to the global ground coordinate system. In principle this approach can be applied for georeferencing of push-broom line scanner imagery, but this process is highly inefficient. Due to the large number of unknowns a large number of tie and control points is necessary for orientation determination. To allow an operational processing the direct measurement of exterior orientation using GPS and INS and additional information is inevitable. Within this article the geometric processing of high resolution line scanner imagery is described and the test results from different airborne test flights flown in 1998 are given.

The reduction of 2′‐ribonucleotides to 2′‐deoxyribonucleotides, a unique step in DNA formation, is catalyzed by ribonucleotide reductase (RRase), an allosterically regulated, cell cycle‐dependent enzyme. This work reports a reversible impairment of DNA formation and ribonucleotide reduction upon manganese depletion in Bacillus subtilis demonstrated through in vivo labeling with nucleic acid precursors and enzyme assays with ether‐permeabilized cells. No deoxyadenosylcobalamin‐dependent reduction of ribonucleotides was detected in the cytosol, and the properties of a partially purified enzyme fraction, i.e., sensitivity towards EDTA and hydroxyurea (HU), indicated a metal‐dependent type of RRase. The enzyme was enriched by gel filtration on Superose ™ 12 from glycerol‐ or fumarate‐grown cells and submitted to Q‐band electron paramagnetic resonance (EPR) spectroscopy for further characterization of the metal center. A distinct Mn(II) signal was obtained in both preparations characteristic of a protein‐bound manganese in a mononuclear metal center with axial symmetry. The intensity of this Mn signal was not affected by addition of the radical scavenger HU (10 mM) but reduced in the presence of 2.5 mM EDTA. On the basis of these results, we suggest that Bacillus subtilis has a Mn‐dependent ribonucleotide reductase.

We are informed by the senior author, Dr. R.L. Krauth-Siegel, that the Trypanosoma brucei tryparedoxin sequence has now been given the accession number AJ006403.

The registration and geometric rectification of airborne scanner imagery is a prerequisite for the processing and analysis of this type of images. Within the paper the geometric processing of scanner imagery acquired from the Digital Photogrammetric Assembly (DPA), which is an airborne camera consisting of three pan–chromatic line arrays for stereo imaging and four line arrays for multi–spectral imaging will be described. The sensor system is completed by a module consisting of a differential GPS receiver configuration and an Inertial Navigation System (INS). Within the paper the georeferencing by an integrated GPS/INS component in combination with an aerial triangulation based on the three–line principle of the camera is presented. Additionally, the generation of DTM and ortho images from this type of imagery is demonstrated.

Airborne pushbroom systems for the direct acquisition of digital imagery enable the simultaneous capture of high quality 3D and multispectral information of a scene. The combination of geometric and radiometric information should improve tasks like DTM generation - usually solely based on stereo imagery - and landuse classification, which is traditionally restricted to the interpretation of spectral information. Within this paper these assumptions are confirmed utilizing datasets of the DPA (Digital Photogrammetric Assembly), a scanning airborne sensor which records simultaneously high spatial resolution stereo and multispectral image. Since the surface reconstruction and ortho image generation from airborne scanner imagery, which is a prerequisite for the proposed approach is different to standard procedures using full frame images, this process will be described in the first part of the paper. Afterwards the benefits of a combined evaluation of stereo and multispectral data will be demonstrated for two tasks, the generation of Digital Terrain Models and the landuse classification for thematic mapping.

A gene has been cloned from Trypanosoma brucei which encodes a protein of 144 amino acid residues containing the thioredoxin-like motif WCPPCR. Overexpression of the gene in E. coli resulted in 4 mg pure protein from 100 ml bacterial cell culture. Recombinant T. brucei tryparedoxin acts as a thiol-disulfide oxidoreductase. It is spontaneously reduced by trypanothione. This dithiol, exclusively found in parasitic protozoa, also reduces E. coli glutaredoxin but not thioredoxin. The trypanothione/tryparedoxin couple is an effective reductant of T. brucei ribonucleotide reductase. Like thioredoxins it has a poor GSH:disulfide transhydrogenase activity. The catalytic properties of tryparedoxin are intermediate between those of classical thioredoxins and glutaredoxins which indicates that these parasite proteins may form a new class of thiol-disulfide oxidoreductases.