K. Jacobsen, H. Topan, A. Cam, Mustafa Özendi, M. Oruc
The image quality of Pléiades-1A panchromatic and multispectral as well as pan-sharpened images has been analyzed. The original images are available with 12 bit radiometric resolution, but for mapping purposes often this is reduced to 8 bit, corresponding to the grey value resolution of the computer screens. Therefore, original images as well as the 8 bit images were investigated. Pléiades images are distributed with 50 cm ground sampling distance (GSD) in spite of the original resolution with 70 cm GSD. For this the effective image quality was determined by edge analysis. The edge analysis can be influenced by image sharpening. An image sharpening usually enlarges the image noise, which however can be reduced by filtering. This can influence the presentation of small image details, so in addition to edge and noise analysis image details in the Pléiades images were compared with the details visible in satellite images taken by other sensors having similar ground resolution. A blur analysis did not improve the information about image quality. In the Zonguldak test site (Turkey) Pléiades images are compared with WorldView-1-, QuickBirdand IKONOS-images. The zooming from 70 cm to 50 cm GSD could not be identified by the investigation of the Pléiades image quality. It leads to an even better quality than of the WorldView-1and QuickBird images with an originally higher resolution. Zusammenfassung: Bildqualität von Triplet Bundle und Pan-sharpened Bildern des Systems Pléiades-1A. Die Bildqualität von panchromatischen, multispektralen und pan-geschärften Pléiades-1A Bildern wurde untersucht. Die Originalbilder haben eine radiometrische Auflösung von 12 bit, für die Kartenerstellung werden sie jedoch häufig auf 8 bit reduziert, weswegen sowohl die Originalbilder als auch 8-bit-Bilder analysiert wurden. Pléiades-Bilder werden mit 50 cm Objektpixelgröße ausgeliefert, obwohl die geometrische Auflösung nur 70 cm beträgt. Aus diesem Grund war eine Untersuchung der Bildqualität mittels Kantenanalyse erforderlich. Die Kantenanalyse kann durch Bildschärfung beeinflusst werden. Dieses erhöht normalerweise das Bildrauschen. Das Bildrauschen lässt sich durch Filterung reduzieren, was wiederum die Erkennbarkeit kleiner Bilddetails verschlechtern kann. Aus diesem Grund wurde auch das Bildrauschen untersucht. Eine blur-Untersuchung verbesserte die Information über die Bildqualität nicht. Von dem Testgebiet Zonguldak, Türkei, sind auch WorldView-1-, QuickBirdund IKONOS-Bilder vorhanden, die einen Vergleich von Bilddetails ermöglichen. Die Vergrößerung der Pléiades-Bilder von 70 cm auf 50 cm Objektpixelgröße konnte nicht durch eine reduzierte Bildqualität nachgewiesen werden. Vielmehr waren die Pléiades-Bilder sogar qualitativ besser als die WorldView-1und die QuickBird-Bilder, die eine höhere geometrische Auflösung besitzen.
分析了plimades - 1a全色、多光谱及泛锐化图像的成像质量。原始图像具有12位辐射分辨率，但出于映射目的，通常将其降低到8位，对应于计算机屏幕的灰度值分辨率。因此，我们对原始图像和8位图像进行了研究。尽管原始分辨率为70 cm GSD，但plimiades图像以50 cm的地面采样距离(GSD)分布。通过边缘分析确定图像的有效质量。图像锐化会影响边缘分析。图像锐化通常会增大图像噪声，但是可以通过滤波来减小噪声。这可能会影响小图像细节的呈现，因此，除了边缘和噪声分析之外，还将pliades图像中的图像细节与具有类似地面分辨率的其他传感器拍摄的卫星图像中可见的细节进行了比较。模糊分析并没有改善图像质量的信息。在土耳其的Zonguldak试验场，将pl宇航图像与WorldView-1-、quickbird和ikonos -图像进行了比较。从70 cm到50 cm GSD的变焦无法通过调查pl图像质量来识别。它可以产生比worldview -1和QuickBird图像更好的质量，并且具有更高的分辨率。Zusammenfassung: Bildqualität von Triplet Bundle and Pan-sharpened Bildern des Systems placides - 1a。Die Bildqualität von panchromatischen, multispetralen and pan-geschärften plemides - 1a Bildern wurde untersucht。Die Originalbilder haben eine radiometrische Auflösung von 12位，Die Kartenerstellung werden sie jedoch häufig auf 8位还原，weswegen sowohl Die Originalbilder也auch ach 8位bilder分析器wurden。plassides - bilder werden 50 cm Objektpixelgröße ausgeliefert, obwohl die geomeische Auflösung nur 70 cm beträgt。在德国，地面战争线在德国Bildqualität mittelels Kantenanalyse erderlich。康德分析康德durch Bildschärfung beinfusst werden。Dieses erhöht normalerweise das Bildrauschen。Das Bildrauschen lässt sch durch Filterung reduzieren，是wiederum die Erkennbarkeit kleiner Bilddetails verschlechtern kann。Aus diesem Grund wurde auch das Bildrauschen untersucht。Eine blurb - untersuchung verbesserte die Information 她的死亡Bildqualität夜。引用本文:冯德明，张德明，张德明，张德明，张德明，张德明，张德明，张德明，张德明。Die Vergrößerung der plezimides - bilder von 70 cm或50 cm Objektpixelgröße konnte night durine reduzierte Bildqualität nachgewiesen werden。Vielmehr waren die plezimides - bilder糖化质，也die worldview -1和die QuickBird-Bilder, die eine höhere geomeische Auflösung besitzen。
{"title":"Image Quality Assessment of Pléiades-1A Triplet Bundle and Pan-sharpened Images","authors":"K. Jacobsen, H. Topan, A. Cam, Mustafa Özendi, M. Oruc","doi":"10.1127/PFG/2016/0291","DOIUrl":"https://doi.org/10.1127/PFG/2016/0291","url":null,"abstract":"The image quality of Pléiades-1A panchromatic and multispectral as well as pan-sharpened images has been analyzed. The original images are available with 12 bit radiometric resolution, but for mapping purposes often this is reduced to 8 bit, corresponding to the grey value resolution of the computer screens. Therefore, original images as well as the 8 bit images were investigated. Pléiades images are distributed with 50 cm ground sampling distance (GSD) in spite of the original resolution with 70 cm GSD. For this the effective image quality was determined by edge analysis. The edge analysis can be influenced by image sharpening. An image sharpening usually enlarges the image noise, which however can be reduced by filtering. This can influence the presentation of small image details, so in addition to edge and noise analysis image details in the Pléiades images were compared with the details visible in satellite images taken by other sensors having similar ground resolution. A blur analysis did not improve the information about image quality. In the Zonguldak test site (Turkey) Pléiades images are compared with WorldView-1-, QuickBirdand IKONOS-images. The zooming from 70 cm to 50 cm GSD could not be identified by the investigation of the Pléiades image quality. It leads to an even better quality than of the WorldView-1and QuickBird images with an originally higher resolution. Zusammenfassung: Bildqualität von Triplet Bundle und Pan-sharpened Bildern des Systems Pléiades-1A. Die Bildqualität von panchromatischen, multispektralen und pan-geschärften Pléiades-1A Bildern wurde untersucht. Die Originalbilder haben eine radiometrische Auflösung von 12 bit, für die Kartenerstellung werden sie jedoch häufig auf 8 bit reduziert, weswegen sowohl die Originalbilder als auch 8-bit-Bilder analysiert wurden. Pléiades-Bilder werden mit 50 cm Objektpixelgröße ausgeliefert, obwohl die geometrische Auflösung nur 70 cm beträgt. Aus diesem Grund war eine Untersuchung der Bildqualität mittels Kantenanalyse erforderlich. Die Kantenanalyse kann durch Bildschärfung beeinflusst werden. Dieses erhöht normalerweise das Bildrauschen. Das Bildrauschen lässt sich durch Filterung reduzieren, was wiederum die Erkennbarkeit kleiner Bilddetails verschlechtern kann. Aus diesem Grund wurde auch das Bildrauschen untersucht. Eine blur-Untersuchung verbesserte die Information über die Bildqualität nicht. Von dem Testgebiet Zonguldak, Türkei, sind auch WorldView-1-, QuickBirdund IKONOS-Bilder vorhanden, die einen Vergleich von Bilddetails ermöglichen. Die Vergrößerung der Pléiades-Bilder von 70 cm auf 50 cm Objektpixelgröße konnte nicht durch eine reduzierte Bildqualität nachgewiesen werden. Vielmehr waren die Pléiades-Bilder sogar qualitativ besser als die WorldView-1und die QuickBird-Bilder, die eine höhere geometrische Auflösung besitzen.","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87965452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Using Digital Aerial Photogrammetry and the Random Forest Approach to Model Forest Inventory Attributes in Beech- and Spruce-dominated Central European Forests","authors":"C. Straub, C. Stepper","doi":"10.1127/PFG/2016/0292","DOIUrl":"https://doi.org/10.1127/PFG/2016/0292","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75840563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tri-Stereo Model Orientation of High-Resolution Satellite Imagery Combining Ground Control Points and Lines","authors":"Jinshan Cao, Xiuxiao Yuan, Yi Fang","doi":"10.1127/PFG/2016/0293","DOIUrl":"https://doi.org/10.1127/PFG/2016/0293","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89606248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Bareth, J. Bendig, N. Tilly, D. Hoffmeister, H. Aasen, A. Bolten
{"title":"A Comparison of UAV- and TLS-derived Plant Height for Crop Monitoring: Using Polygon Grids for the Analysis of Crop Surface Models (CSMs)","authors":"G. Bareth, J. Bendig, N. Tilly, D. Hoffmeister, H. Aasen, A. Bolten","doi":"10.1127/PFG/2016/0289","DOIUrl":"https://doi.org/10.1127/PFG/2016/0289","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78017452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Ressl, Herbert Brockmann, G. Mandlburger, N. Pfeifer
{"title":"Dense Image Matching vs. Airborne Laser Scanning – Comparison of two methods for deriving terrain models","authors":"C. Ressl, Herbert Brockmann, G. Mandlburger, N. Pfeifer","doi":"10.1127/PFG/2016/0288","DOIUrl":"https://doi.org/10.1127/PFG/2016/0288","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76197034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Kaasalainen, O. Nevalainen, T. Hakala, K. Anttila
We have studied the effect of incidence angle on the spectral content of leaf measurements from hyperspectral light detection and ranging (lidar) data. New results obtained for different ornamental plant leaves indicate that their backscatter properties do not follow the Lambert scattering law, especially in the visible wavelength range: specular reflections were observed near the normal incidence. Also the vegetation spectral indices, such as normalized difference vegetation index (NDVI), or even the simple ratios may change with the laser incidence angle to the target. The reason for this is the difference in their backscatter vs. intensity behaviour between visible and near-infrared (NIR) wavelengths. In comparison with earlier results it turns out that this phenomenon seems to depend on the internal structure and surface properties of leaves. Further information on the extent and role of this effect for different leaves is needed, but our results indicate that the nature of laser reflection in tree canopies may vary between species. The calibration of hyperspectral lidar vegetation reflectance measurements must be further studied by rigorous experiments and modelling. Zusammenfassung: Abhängigkeit von Vegetationsindices für Blätter vom Inzidenzwinkel aus hyperspektralen Laserscanner-Messungen. In diesem Beitrag wird der Einfluss des Einfallswinkels auf spektrale Indices, welche aus hyperspektralen Laserscanner-Messungen von Blättern abgeleitet werden, untersucht. Neue Ergebnisse für Blätter von verschiedenen Zierpflanzen zeigen, dass deren Rückstreuverhalten vor allem im sichtbaren Bereich des elektromagnetischen Spektrums nicht dem eines Lambertschen Strahlers entspricht: Bei genähert senkrechter Einfallrichtung wurde gerichtete Reflexion beobachtet. Auch spektrale Vegetationsindices wie z. B. der Normalized Difference Vegetation Index (NDVI) oder auch nur einfache Verhältnisse können sich mit dem Einfallswinkel des Laserstrahls ändern. Der Grund dafür ist ein unterschiedliches Rückstreuverhalten im sichtbaren Bereich bzw. im nahen Infrarot. Im Vergleich mit früheren Ergebnissen scheint dieses Phänomen von der inneren Struktur und den Oberflächeneigenschaften der Blätter abzuhängen. Während tiefergehende Untersuchungen zum Ausmaß und zur Rolle dieses Effekts noch ausstehen, weisen unsere Ergebnisse darauf hin, dass die Art der Laserreflexion für unterschiedliche Spezies variieren könnte. Die Kalibrierung von Reflexionsgraden aus multispektralen Laserscanner-Messungen erfordert weitere Studien in Hinblick auf eine strenge Modellierung und experimentelle Validierung.
利用高光谱探测和测距(激光雷达)数据，研究了入射角对叶片光谱含量的影响。不同观赏植物叶片的后向散射特性不遵循朗伯散射定律，特别是在可见光范围内，在正入射附近存在镜面反射。植被光谱指数，如归一化植被指数(NDVI)，甚至简单的比值也会随着激光入射角的变化而变化。其原因是它们在可见光和近红外(NIR)波长之间的后向散射和强度行为的差异。与之前的结果相比，结果表明这种现象似乎取决于叶子的内部结构和表面特性。在不同的叶片中，这种效应的程度和作用还需要进一步的信息，但我们的研究结果表明，树木冠层中激光反射的性质可能因物种而异。高光谱激光雷达植被反射率测量的定标必须通过严格的实验和模拟来进一步研究。Zusammenfassung: Abhängigkeit von Vegetationsindices f r Blätter vom Inzidenzwinkel aus高光谱激光扫描仪- messungen。在Einfallswinkels光谱指数，welche，超光谱激光扫描仪- messungen von Blättern abgelitet werden, untersuht。Neue Ergebnisse f r Blätter von verschiedenen Zierpflanzen zeigen, dass deren rckstreuverhalten vorallem m sichtbaren berichschen elekmagnetischen spectres ebertschen Strahlers entspritht: Bei genähert senkrechter Einfallrichtung wurde gerichtete reflationbebachet。各光谱植被指数为z. B. der归一化植被指数(NDVI);各光谱植被指数(NDVI)与各光谱植被指数(NDVI)的比值为Verhältnisse können，其中Einfallswinkel des Laserstrahls ändern。Der ground dafrist in unterschiedliches rckstreuverhalten in sichtbaren Bereich bzw。我住在南安普敦。在Vergleich mit heren Ergebnissen scheint dieses Phänomen von der inner Struktur and den Oberflächeneigenschaften der Blätter abzuhängen。Während tiferergehende Untersuchungen zum ausmasß und zur Rolle dieses effects noch aussteen, weisen unserere Ergebnisse daraufhin, dass Art der laserreflex fre unterschiedliche Spezies varien könnte。多光谱激光扫描器反射光栅的光学特性研究[j] .德国欣布利克大学研究中心，光学建模与实验验证。
{"title":"Incidence Angle Dependency of Leaf Vegetation Indices from Hyperspectral Lidar Measurements","authors":"S. Kaasalainen, O. Nevalainen, T. Hakala, K. Anttila","doi":"10.1127/PFG/2016/0287","DOIUrl":"https://doi.org/10.1127/PFG/2016/0287","url":null,"abstract":"We have studied the effect of incidence angle on the spectral content of leaf measurements from hyperspectral light detection and ranging (lidar) data. New results obtained for different ornamental plant leaves indicate that their backscatter properties do not follow the Lambert scattering law, especially in the visible wavelength range: specular reflections were observed near the normal incidence. Also the vegetation spectral indices, such as normalized difference vegetation index (NDVI), or even the simple ratios may change with the laser incidence angle to the target. The reason for this is the difference in their backscatter vs. intensity behaviour between visible and near-infrared (NIR) wavelengths. In comparison with earlier results it turns out that this phenomenon seems to depend on the internal structure and surface properties of leaves. Further information on the extent and role of this effect for different leaves is needed, but our results indicate that the nature of laser reflection in tree canopies may vary between species. The calibration of hyperspectral lidar vegetation reflectance measurements must be further studied by rigorous experiments and modelling. Zusammenfassung: Abhängigkeit von Vegetationsindices für Blätter vom Inzidenzwinkel aus hyperspektralen Laserscanner-Messungen. In diesem Beitrag wird der Einfluss des Einfallswinkels auf spektrale Indices, welche aus hyperspektralen Laserscanner-Messungen von Blättern abgeleitet werden, untersucht. Neue Ergebnisse für Blätter von verschiedenen Zierpflanzen zeigen, dass deren Rückstreuverhalten vor allem im sichtbaren Bereich des elektromagnetischen Spektrums nicht dem eines Lambertschen Strahlers entspricht: Bei genähert senkrechter Einfallrichtung wurde gerichtete Reflexion beobachtet. Auch spektrale Vegetationsindices wie z. B. der Normalized Difference Vegetation Index (NDVI) oder auch nur einfache Verhältnisse können sich mit dem Einfallswinkel des Laserstrahls ändern. Der Grund dafür ist ein unterschiedliches Rückstreuverhalten im sichtbaren Bereich bzw. im nahen Infrarot. Im Vergleich mit früheren Ergebnissen scheint dieses Phänomen von der inneren Struktur und den Oberflächeneigenschaften der Blätter abzuhängen. Während tiefergehende Untersuchungen zum Ausmaß und zur Rolle dieses Effekts noch ausstehen, weisen unsere Ergebnisse darauf hin, dass die Art der Laserreflexion für unterschiedliche Spezies variieren könnte. Die Kalibrierung von Reflexionsgraden aus multispektralen Laserscanner-Messungen erfordert weitere Studien in Hinblick auf eine strenge Modellierung und experimentelle Validierung.","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85565691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Automatic Generation of Orthorectified High Resolution Satellite Imagery – a Case Study for Saudi Arabia","authors":"M. Alrajhi, C. Heipke","doi":"10.1127/pfg/2016/0285","DOIUrl":"https://doi.org/10.1127/pfg/2016/0285","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87513530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unmanned aerial vehicles (UAV) are increasingly used for topographic mapping. Despite the flexibility gained when using those devices, one has to invest more effort for ground control measurements compared to conventional photogrammetric airborne data acquisition, because positioning devices on UAVs are generally less accurate. Additionally, the limited quality of employed end-user cameras asks for self-calibration, which might cause some problems as well. A good distribution of ground control points (GCPs) is not only needed to solve for the absolute orientation of the image block in the desired coordinate frame, but also to mitigate block deformation effects which are resulting mainly from remaining systematic errors in the camera calibration. In this paper recent developments in the UAV-hardware market are picked up: some providers equip fixed-wing UAVs with RTK-GNSS-enabled 2-frequency receivers and set up a processing pipeline which allows them to promise an absolute block orientation in a similar accuracy range as through traditional indirect sensor orientation. Besides the analysis of the actually obtainable accuracy, when one of those systems is used, we examine the effect different flight directions and altitudes (cross flight) have onto the bundle adjustment. For this purpose two test areas have been prepared and flown with a fixed-wing UAV. Results are promising: not only the absolute image orientation gets significantly enhanced when the RTK-option is used, also block deformation is reduced. However, remaining offsets originating from time synchronization or camera event triggering should be considered during flight planning. In flat terrains a cross flight pattern helps to enhance results because of better and more reliable self-calibration.
{"title":"Accuracy analysis of photogrammetric UAV image blocks: influence of onboard RTK-GNSS and cross flight patterns","authors":"M. Gerke, H.-J. Przybilla","doi":"10.1127/PFG/2016/0284","DOIUrl":"https://doi.org/10.1127/PFG/2016/0284","url":null,"abstract":"Unmanned aerial vehicles (UAV) are increasingly used for topographic mapping. Despite the flexibility gained when using those devices, one has to invest more effort for ground control measurements compared to conventional photogrammetric airborne data acquisition, because positioning devices on UAVs are generally less accurate. Additionally, the limited quality of employed end-user cameras asks for self-calibration, which might cause some problems as well. A good distribution of ground control points (GCPs) is not only needed to solve for the absolute orientation of the image block in the desired coordinate frame, but also to mitigate block deformation effects which are resulting mainly from remaining systematic errors in the camera calibration. In this paper recent developments in the UAV-hardware market are picked up: some providers equip fixed-wing UAVs with RTK-GNSS-enabled 2-frequency receivers and set up a processing pipeline which allows them to promise an absolute block orientation in a similar accuracy range as through traditional indirect sensor orientation. Besides the analysis of the actually obtainable accuracy, when one of those systems is used, we examine the effect different flight directions and altitudes (cross flight) have onto the bundle adjustment. For this purpose two test areas have been prepared and flown with a fixed-wing UAV. Results are promising: not only the absolute image orientation gets significantly enhanced when the RTK-option is used, also block deformation is reduced. However, remaining offsets originating from time synchronization or camera event triggering should be considered during flight planning. In flat terrains a cross flight pattern helps to enhance results because of better and more reliable self-calibration.","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77698915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
for emergency driving training (Randt et al. 2007). Some application areas such as emergency management (Zlatanova & li 2008) or indoor navigation (BeckeR et al. 2009) even require information of the building’s interior on a city level. These models may vary with regard to geometrical and semantical complexity and to the degree of deviation from the corresponding real world objects. Complexity levels then are the result of specific data acqui
进行紧急驾驶训练(Randt et al. 2007)。一些应用领域，如应急管理(Zlatanova & li 2008)或室内导航(BeckeR et al. 2009)甚至需要城市层面的建筑内部信息。这些模型可能在几何和语义复杂性以及与相应的现实世界对象的偏差程度方面有所不同。复杂程度则是特定数据获取的结果
{"title":"Evaluation Criteria for Recent LoD Proposals for City-GML Buildings","authors":"Marc-O. Löwner, G. Gröger","doi":"10.1127/PFG/2016/0283","DOIUrl":"https://doi.org/10.1127/PFG/2016/0283","url":null,"abstract":"for emergency driving training (Randt et al. 2007). Some application areas such as emergency management (Zlatanova & li 2008) or indoor navigation (BeckeR et al. 2009) even require information of the building’s interior on a city level. These models may vary with regard to geometrical and semantical complexity and to the degree of deviation from the corresponding real world objects. Complexity levels then are the result of specific data acqui","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87794248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bi-temporal Change Detection, Change Trajectories and Time Series Analysis for Forest Monitoring","authors":"Frank Thonfeld, Antje Hecheltjen, G. Menz","doi":"10.1127/PFG/2015/0259","DOIUrl":"https://doi.org/10.1127/PFG/2015/0259","url":null,"abstract":"","PeriodicalId":56096,"journal":{"name":"Photogrammetrie Fernerkundung Geoinformation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89503868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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