The Use of Deep Learning Methods for Object Height Estimation in High Resolution Satellite Images.

Processing single high-resolution satellite images may provide a lot of important information about the urban landscape or other applications related to the inventory of high-altitude objects. Unfortunately, the direct extraction of specific features from single satellite scenes can be difficult. However, the appropriate use of advanced processing methods based on deep learning algorithms allows us to obtain valuable information from these images. The height of buildings, for example, may be determined based on the extraction of shadows from an image and taking into account other metadata, e.g., the sun elevation angle and satellite azimuth angle. Classic methods of processing satellite imagery based on thresholding or simple segmentation are not sufficient because, in most cases, satellite scenes are not spectrally heterogenous. Therefore, the use of classical shadow detection methods is difficult. The authors of this article explore the possibility of using high-resolution optical satellite data to develop a universal algorithm for a fully automated estimation of object heights within the land cover by calculating the length of the shadow of each founded object. Finally, a set of algorithms allowing for a fully automatic detection of objects and shadows from satellite and aerial imagery and an iterative analysis of the relationships between them to calculate the heights of typical objects (such as buildings) and atypical objects (such as wind turbines) is proposed. The city of Warsaw (Poland) was used as the test area. LiDAR data were adopted as the reference measurement. As a result of final analyses based on measurements from several hundred thousand objects, the global accuracy obtained was ±4.66 m.

Application of Multitemporal Change Detection in Radar Satellite Imagery Using REACTIV-Based Method for Geospatial Intelligence.

Constant monitoring of airports and aviation bases has become one of the priorities in today's strategic security. It results in the necessity to develop the potential of satellite Earth observation systems and to intensify the efforts to develop the technologies of processing SAR data, in particular in the aspect of detecting changes. The aim of this work is to develop a new algorithm based on the modified core REACTIV in the multitemporal detection of changes in radar satellite imagery. For the purposes of the research works, the new algorithm implemented in the Google Earth Engine environment has been transformed so that it would meet the requirements posed by imagery intelligence. The assessment of the potential of the developed methodology was performed based on the analysis of the three main aspects of change detection: analysis of infrastructural changes, analysis of military activity, and impact effect evaluation. The proposed methodology enables automated detection of changes in multitemporal series of radar imagery. Apart from merely detecting the changes, the method also allows for the expansion of the change analysis result by adding another dimension: the determination of the time of the change.

Design and Performance Analysis of a Constellation of Nanosatellites to Monitor Water Quality in the Southern Catchment of the Baltic Sea.

The quality of inland waters has a significant influence on human life and the functioning of the environment. The disasters that result from water pollution may cause major financial losses and lead to irreversible changes in the ecosystem, such as the dying out of endemic species of plants and animals. Quick detection of pollution sources may minimise those negative effects and reduce the costs of their elimination. The study presents a constellation design that provides imagery in the optic range and that might supplement the point water quality measurements that are conducted in situ. The area of interest was the southern catchment of the Baltic Sea and the main rivers in the region. The requirements for the designed mission were defined in reference to the remote sensing needs concerning the monitoring of water quality, the characteristics of the analysed area, and weather conditions. Based on these requirements, the Simera Sense MultiScape100 CIS sensor and the M6P nanosatellite manufactured by NanoAvionics were selected. The authors proposed a process for selecting the optimum orbit, taking into account the area of interest, the possibilities of the satellite platform, and of the sensor's optics. As a result of the analyses, four concepts of creating a constellation were presented. Each constellation consisted of four nanosatellites. The designs were then subjected to performance analysis, considering the lighting limitations. Among the proposed systems, the constellation designed by the authors was distinguished; it used four orbital planes and achieved the coverage and availability of imagery in the time that was best suited to monitoring the waters. Thanks to a small number of platforms, the costs of the mission are relatively low, and it might significantly improve awareness of the current state of surface waters in the southern catchment of the Baltic Sea.

The Conception of Test Fields for Fast Geometric Calibration of the FLIR VUE PRO Thermal Camera for Low-Cost UAV Applications.

The dynamic evolution of photogrammetry led to the development of numerous methods of geometric calibration of cameras, which are mostly based on building flat targets (fields) with features that can be distinguished in the images. Geometric calibration of thermal cameras for UAVs is an active research field that attracts numerous researchers. As a result of their low price and general availability, non-metric cameras are being increasingly used for measurement purposes. Apart from resolution, non-metric sensors do not have any other known parameters. The commonly applied process is self-calibration, which enables the determining of the approximate elements of the camera's interior orientation. The purpose of this work was to analyze the possibilities of geometric calibration of thermal UAV cameras using proposed test field patterns and materials. The experiment was conducted on a FLIR VUE PRO thermal camera dedicated to UAV platforms. The authors propose the selection of various image processing methods (histogram equalization, thresholding, brightness correction) in order to improve the quality of the thermograms. The consecutive processing methods resulted in over 80% effectiveness on average by 94%, 81%, and 80 %, respectively. This effectiveness, for no processing and processing with the use of the filtering method, was: 42% and 38%, respectively. Only high-pass filtering did not improve the obtained results. The final results of the proposed method and structure of test fields were verified on chosen geometric calibration algorithms. The results of fast and low-cost calibration are satisfactory, especially in terms of the automation of this process. For geometric correction, the standard deviations for the results of specific methods of thermogram sharpness enhancement are two to three times better than results without any correction.

Cationic Emulsion Polymerization of Octamethylcyclotetrasiloxane (D4) in Mixtures with Alkoxysilanes.

The cationic emulsion polymerization of octamethylcyclotetrasiloxane (D4) in mixtures with methyltriethoxysilane (MTES) and vinyltriethoxysilane (VTES) was studied by FTIR ATR, GC, the development of a toluene insoluble fraction of the polymer and a gravimetric analysis. The polymerization of D4 alone was also conducted for comparison and, additionally, the development of molecular weight of polydimethylsiloxane (PDMS) obtained in that process was studied by GPC. Dodecylbenzenesulphonic acid (DBSA) was used as a surfactant and catalyst. The process was carried out in a "starved feed" mode by adding dropwise the monomer mixture to the aqueous solution of DBSA. FTIR ATR spectra were recorded by the sensor placed in the probe tip of a ReactIR 15TM apparatus. It was found that the silicone polymer formation proceeded faster when D4 was polymerized in the mixture with alkoxysilanes, especially in the beginning of the process, and that already at the beginning of the process, the partly crosslinked polymer was formed. The induction period of ca. 30 min was observed and the concentration of cyclic siloxanes (D4 and decamethylcyclopentasiloxane-D5) remained at a very low level in the course of the reaction and only traces were detected in the final product. The particle size development in the course of the reaction was also studied and it was found that the particle size distribution was bimodal and was broadening as the reaction proceeded, though this phenomenon was less distinct when D4 was polymerized in the mixtures with alkoxysilanes. The structure of the reaction product was confirmed by 29Si NMR.

Pre-Processing of Panchromatic Images to Improve Object Detection in Pansharpened Images.

In recent years, many techniques of fusion of multi-sensors satellite images have been developed. This article focuses on examining and improvement the usability of pansharpened images for object detection, especially when fusing data with a high GSD ratio. A methodology to improve an interpretative ability of pansharpening results is based on pre-processing of the panchromatic image using Logarithmic-Laplace filtration. The proposed approach was used to examine several different pansharpening methods and data sets with different spatial resolution ratios, i.e., from 1:4 to 1:60. The obtained results showed that the proposed approach significantly improves an object detection of fused images, especially for imagery data with a high-resolution ratio. The interpretative ability was assessed using qualitative method (based on image segmentation) and quantitative method (using an indicator based on the Speeded Up Robust Features (SURF) detector). In the case of combining data acquired with the same sensor the interpretative potential had improved by a dozen or so per cent. However, for data with a high resolution ratio, the improvement was several dozen, or even several hundred per cents, in the case of images blurred after pansharpening by the classic method (with original panchromatic image). Image segmentation showed that it is possible to recognize narrow objects that were originally blurred and difficult to identify. In addition, for panchromatic images acquired by WorldView-2, the proposed approach improved not only object detection but also the spectral quality of the fused image.

Integration of Satellite Data with High Resolution Ratio: Improvement of Spectral Quality with Preserving Spatial Details.

Commonly used image fusion techniques generally produce good results for images obtained from the same sensor, with a standard ratio of spatial resolution (1:4). However, an atypical high ratio of resolution reduces the effectiveness of fusion methods resulting in a decrease in the spectral or spatial quality of the sharpened image. An important issue is the development of a method that allows for maintaining simultaneous high spatial and spectral quality. The authors propose to strengthen the pan-sharpening methods through prior modification of the panchromatic image. Local statistics of the differences between the original panchromatic image and the intensity of the multispectral image are used to detect spatial details. The Euler's number and the distance of each pixel from the nearest pixel classified as a spatial detail determine the weight of the information collected from each integrated image. The research was carried out for several pan-sharpening methods and for data sets with different levels of spectral matching. The proposed solution allows for a greater improvement in the quality of spectral fusion, while being able to identify the same spatial details for most pan-sharpening methods and is mainly dedicated to Intensity-Hue-Saturation based methods for which the following improvements in spectral quality were achieved: about 30% for the urbanized area and about 15% for the non-urbanized area.

Fast Orientation of Video Images of Buildings Acquired from a UAV without Stabilization.

The aim of this research was to assess the possibility of conducting an absolute orientation procedure for video imagery, in which the external orientation for the first image was typical for aerial photogrammetry whereas the external orientation of the second was typical for terrestrial photogrammetry. Starting from the collinearity equations, assuming that the camera tilt angle is equal to 90°, a simplified mathematical model is proposed. The proposed method can be used to determine the X, Y, Z coordinates of points based on a set of collinearity equations of a pair of images. The use of simplified collinearity equations can considerably shorten the processing tine of image data from Unmanned Aerial Vehicles (UAVs), especially in low cost systems. The conducted experiments have shown that it is possible to carry out a complete photogrammetric project of an architectural structure using a camera tilted 85°-90° ( φ or ω) and simplified collinearity equations. It is also concluded that there is a correlation between the speed of the UAV and the discrepancy between the established and actual camera tilt angles.

Terrestrial and aerial laser scanning data integration using wavelet analysis for the purpose of 3D building modeling.

Visualization techniques have been greatly developed in the past few years. Three-dimensional models based on satellite and aerial imagery are now being enhanced by models generated using Aerial Laser Scanning (ALS) data. The most modern of such scanning systems have the ability to acquire over 50 points per square meter and to register a multiple echo, which allows the reconstruction of the terrain together with the terrain cover. However, ALS data accuracy is less than 10 cm and the data is often incomplete: there is no information about ground level (in most scanning systems), and often around the facade or structures which have been covered by other structures. However, Terrestrial Laser Scanning (TLS) not only acquires higher accuracy data (1-5 cm) but is also capable of registering those elements which are incomplete or not visible using ALS methods (facades, complicated structures, interiors, etc.). Therefore, to generate a complete 3D model of a building in high Level of Details, integration of TLS and ALS data is necessary. This paper presents the wavelet-based method of processing and integrating data from ALS and TLS. Methods of choosing tie points to combine point clouds in different datum will be analyzed.

[The prevalence of spinal osteoporosis in relation to the clinical forms and advance of cervical spondylosis in male patients]. / Czestosc wystepowania osteoporozy kregoslupa w zaleznosci od rodzaju i stopnia nasilenia choroby zwyrodnieniowej kregoslupa szyjnego u mezczyzn.

The research was performed on 36 male patients between 65 and 83 years who were either hospitalised or treated in the out-patients clinic due to cervical spondylosis. The aim of the research was to evaluate the frequency of spinal osteoporosis relating to the type and severity of degenerative lesions in cervical spine. The study showed significant relation between the degree of advance of cervical spondylosis and the prevalence of osteoporosis in the study group. The authors have emphasized the need of precise evaluation and differentiation of presented forms of degenerative spine disease.

[The influence of hypersensitivity to nickel, chrome and cobalt on the process of fracture healing in patients treated operatively by stable osteosynthesis]. / Wplyw nadwrazliwosci na nikiel, kobalt i chrom na przebieg procesu gojenia sie zlaman u pacjentów leczonych operacyjnie technikami stabilnej osteosyntezy.

The aim of the study was to evaluate the frequency of occurrence of the hypersensitivity to nickel, chrome and cobalt in patients with longbone fractures. Two groups of patients were compared. The first group was composed of those treated operatively by stable osteosynthesis with the use of metal implants. The control group consisted of patients who have never been operated. Additionally, the influence of recognized hypersensitivity on the process of fracture healing was estimated. The study group consisted of 80 and the control group of 65 patients. All patients were patch tested with metal salts. The correlation was sought between hypersensitivity to metal in the study group, and incidence of complications relating to fracture healing. There was no significant difference observed both in frequency of occurrence of hypersensitivity to nickel, chrome and cobalt among patients treated operatively, and those treated conservatively, as well. There was no correlation between occurrence of hypersensitivity to the ions of metals, and complications in the process of fracture healing.

[Hip arthroplasty in osteopetrosis: technical problems and operative solutions. Case report]. / Alloplastyka stawu biodrowego w osteopetrozie: techniczne problemy i operacyjne rozwiazania. Opis przypadku.

We present a patient with marble bone disease, who went through hip arthroplasty due to femoral neck fracture. We focused on large technical difficulties during the operation, resulting from sclerotisation and total atresia of femoral bone marrow cavity. We discussed some operative solutions which facilitate prosthesis implantation in patients with osteopetrosis.

[Neglected case of chondrosarcoma causing deformity of the shoulder girdle--case report]. / Zaniedbana postac chrzestniakomiesaka znieksztalcajaca obrecz barkowa--opis przypadku.

We have presented a patient's case with advanced form of chondrosarcoma in the scapula causing enormous deformity of shoulder girdle and additionally presenting with metastases in both lungs. Monstrous extent of deformity was developed due to patient's disagreement with proposed therapy which lasted over two years. We wish to present the adaptation ability allowing the patient to perform active form of life and run business in spite of the huge deformity of the shoulder.

[Tibiotalocalcaneal arthrodesis with a retrograde, locked intramedullary nail in treatment of posttraumatic hindfoot and distal tibia deformity--preliminary report]. / Atrodeza pietowo-skokowo-goleniowa z zastosowaniem sródszpikowego, odpietowego gwozdzia ryglowanego w leczeniu pourazowych deformacji tylostopia i konca dalszego piszczeli--doniesienie wstepne.

The authors reviewed their results of tibiotalocalcaneal arthrodesis by retrograde intramedullary nail as a salvage procedure in treatment of the most severe squeal of talar, calcanear, ankle and pilon fractures in twelve patients. Their average age was 55 years. The average follow up ranged from 8 to 25 months. Patients were assessed by AOFAS hindfoot scale and patient satisfaction. The arthrodesis was performed via lateral, transfibular approach. Solid fusion was achieved in all but one patient. In four patients final foot position was not an optimal one for hindfoot arthrodesis. 15 months after surgery a below knee amputation was performed in one patient because of limb ischemia due to posttraumatic lesion of booth tibialis anterior and posterior arteries. Nail construct allows to perform an intrafragmentry compression between bone ends what enhances bone healing and fusion but in some cases nail introducing must be accompanied by osteotomies or pseudoarthrosis resection. The transfibular, lateral approach is extremely useful in exploration of talocalcaneal ant talocrulaljoints. Resection of lateral malleolus reduces soft tissue tension and serve as a source of bone grafts, necessary in many reconstructive procedure.

Surgical treatment of chondrosarcoma with massive bone destruction.

Background. The purpose of the study is to present the results of surgical treatment of chondrosarcoma in patients with massive bone destruction. Material and methods. Surgical treatment involved 10 male patients with chondrosarcoma of pelvis (4 cases), shoulder (4 cases), femur (1 case) and ankle (1 case). We performed the following surgical procedures: complete resection without reconstruction, resection with arthroplasty, resection with bonegraft, amputation or disarticulation. Results. Surgical resection without reconstruction was done in 6 patients. Cemented hip and shoulder arthroplasties were performedin 2 patients. Resection en bloc and bone graft was used in one patient. Amputation of the upper limb was performed in one case due to the enormous size of tumor. None of the patients had perioperative complications. Good outcome and no sign of recurrence was seen in 8 cases. One patient had local recurrence and had to be reoperated 6 months after surgery and another one died 12 months following surgery due to lung metastases. Conclusion. The surgical techniques we used allowed most patients to preserve the limb and its function. The apropriate surgical treatment may be one of the most important factors determining good prognosis in chondrosarcoma.

[Neurological complication after total hip replacement]. / Powiklania neurologiczne po wszczepieniu endoprotezy stawu biodrowego.

The study was performed to evaluate neurological complication of 562 patients who had undergone primary total hip replacement. Lesions of sciatic, femoral and common peroneal nerve occurred in 18 patients (3.2%). Paresis of peroneal nerve was demonstrated in 15 patients. Within this group 7 patients had elongation of the extremity above 4 cm, and 8 patient had it in the range of 2-3 cm. Paresis of common peroneal nerve took place after direct compression of region of fibular head. Lesion of femoral nerve happened twice. In the group of 14 patients clinical symptoms of nerve paresis healed spontaneously in 6-12 month time. In the group of 4 patients (0.7%) constant lost of dorsal flexion of the foot was observed.

[Bone tissue harvesting after multiorgan procurements for preparation of preserved bone allografts]. / Pozyskiwanie tkanki kostnej po pobraniach wielonarzadowych celem przygotowywania allogennych przeszczepów kostnych.

Preserved bone allografts are widely used in orthopaedic and traumatology operations. Until now, bone tissue for the preparation of preserved allografts has been collected from cadaveric donors in forensic medicine departments. Increasing demand for preserved bone allografts and limited number of suitable donors led to a prolongation of the waiting time for this kind of allografts. In 1999 a group of orthopaedic surgeons from the Orthopaedics and Trauma Department of the Pomeranian University of Medical sciences started to retrieve bone tissue following vascularized organ procurements. The aim of this paper is to present the technical details and limitations of this enterprise. Between November 1999 and April 2001 bone tissue was received from 12 out of 20 multiorgan donors (60%).

Regional program for bone allograft harvesting following multiorgan procurement in Pomeranian Academy of Medicine in Szczecin.

In Poland, up to 1999, the bones for allograft preparations had been procured only in mortuaries of forensic medicine departments. The increasing demand for bone transplantations greatly exceeds the supply resulting in a long waiting time for bone allografts. In November 1999, for the first time in Poland, the group of orthopedic surgeons from the Pomeranian Academy of Medicine started the regional program for bone harvesting following vascularized organ procurements. The aim of this paper is to present the technical details and limitations of bone harvesting that occurred in 10 out of 25 multiorgan procurements.

Treatment of osteoporotic pertrochanteric fractures with use of elastic Ender nails in aged people.

INTRODUCTION: Proximal femur fractures are often the first symptom of osteoporosis in old people. Proximal femur fractures in the sequence of minimal trauma are as the rule multifragmental and covers peritrochanteric part. We reviewed effectiveness of Ender technique in aged people with coexisting ostoporosis.
MATERIAL AND METHODS: In 1995-2001 114 patients with osteoporotic peritrochanteric fractures were treated with Ender technique. In our group of patients before operation coexisted in 27 diabetes mellitus, in 52 arteriosclerosis and in 29 patient in different degree senile dementia. We evaluated 76 patient after 6, 12, 18 weeks and 12 months post operatively. We examined range of hip motion and way of walking, on x-rays we evaluated the healing of fracture and shaft-neck angel.
RESULTS: Clinical and radiological evaluation of named group showed a very good result in 45 (60%), a good result in 20 (28%) and a poor results in 11 (12%) of operated patients. The fracture healing occurred in all named group in 84% of patient in 10-24 weeks (mean 17 weeks).
CONCLUSION: Elastic Ender nailing is a technique of choice in the treatment of aged people with osteoporosis and passed medical history. The best result of operative treatment were achieved in patient operated in
1 day after trauma, with high physical and mental dexterity before trauma.