We describe an image-comparison technique of Heidemann and Ritter [4,5] that uses image compressi... more We describe an image-comparison technique of Heidemann and Ritter [4,5] that uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously-observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coalbeds. Some of the rocks are partly covered with lichen. The imagematching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving a 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of diff...
Earth-observation-based mapping plays a critical role in humanitarian responses by providing time... more Earth-observation-based mapping plays a critical role in humanitarian responses by providing timely and accurate information in inaccessible areas, or in situations where frequent updates and monitoring are required, such as in internally displaced population (IDP)/refugee settlements. Manual information extraction pipelines are slow and resource inefficient. Advances in deep learning, especially convolutional neural networks (CNNs), are providing state-of-the-art possibilities for automation in information extraction. This study investigates a deep convolutional neural network-based Mask R-CNN model for dwelling extractions in IDP/refugee settlements. The study uses a time series of very high-resolution satellite images from WorldView-2 and WorldView-3. The model was trained with transfer learning through domain adaptation from nonremote sensing tasks. The capability of a model trained on historical images to detect dwelling features on completely unseen newly obtained images throu...
Satellite imagery is an important information source for research on remote sensing (RS)based hum... more Satellite imagery is an important information source for research on remote sensing (RS)based humanitarian applications. The selection of satellite imagery is one of the most important steps for such research. This paper firstly shows the selection of satellite imagery in past research from 2015 to 2021. It can be found that most research on land cover and land use (LCLU) change caused by conflicts or refugees/internally displaced persons (IDPs) chose medium spatial resolution (MSR) imagery. Most research on dwelling detection of refugee/IDP camps applied high or very high spatial resolution (HSR/VHSR) imagery. There is much research that applied multiple types of satellite imagery for humanitarian applications. Then, the paper presents general characteristics of commonly available optical satellite imagery. Next, with the development of sensors, this paper suggests that data fusion of SPOT5 and Sentinel-2 may be helpful in LCLU change detection caused by refugees/IDPs or conflicts....
Introduction: Juventae Chasma, north of Valles Marineris on Mars contains several light-toned dep... more Introduction: Juventae Chasma, north of Valles Marineris on Mars contains several light-toned deposits (LTD). The four most prominent ones have been informally labeled A – D by [1]. They were interpreted as the result of sub-ice volcano eruptions [1]. More recently , [2] suggested a formation of these and other LTD's on Mars as spring deposits. This work focuses on the mineral composition of mound B, located at 297.7 E,-4.4 N. It has an extension of about 25km in length and 10 km in width. It rises from 2800 m to 266 m below datum. Two stratigraphic units can be identified in HRSC image data: a lower unit, consisting of an alteration of light and dark toned layers with thicknesses roughly ten meters, and an upper unit with layer thicknesses of approximately 100 m, estimated from an HRSC digital terrain model. The mineralogy of this outcrop was investigated by [3] based on IR data from the imaging spectrometer Observatoire pour l'Eau, les Glaces et l'Activité (OMEGA) on M...
Critical information on refugee/internally displaced people (IDP) camps can be provided to humani... more Critical information on refugee/internally displaced people (IDP) camps can be provided to humanitarian organisations to support planning of emergency response and relief using multi-temporal and multi-scale information from satellite imagery and GIS data. Since 2011 we are providing Earth observationbased information services to Médecins Sans Frontières (MSF) on demand. A service on population monitoring has already reached an operational stage. Thereby indicators on population are derived by automated dwelling extraction from (multi-temporal) very high resolution (VHR) satellite imagery. Based on such information, further added-value products are provided to analyse internal camp structure or camp evolution. Two additional services to support groundwater extraction and assess the impact of the camps on the environment are currently under development. So far twenty-five sites in nine countries have been analysed and more than a hundred maps were provided to MSF and other humanitari...
Introduction: We present results of our study of the sulfates and iron oxides in Ophir Chasma, Ma... more Introduction: We present results of our study of the sulfates and iron oxides in Ophir Chasma, Mars, using visible to short wave infrared data (SWIR) from the imaging spectrometers OMEGA and CRISM in conjunction with panchromatic and color imagery, digital elevation models and anaglyphs. Similar studies of the mineralogy of the light-toned deposits (LTD) in Valles Marineris on Mars have been presented by [1-12].
In the project X3D4Pop we investigate if "mixed" satellite image pairs acquired on two ... more In the project X3D4Pop we investigate if "mixed" satellite image pairs acquired on two different dates can be used to calculate meaningful building heights in urban areas. Based on These results, the dependency of urban population estimation models on the availability and quality of 3D data is tested. Study areas are Port-au-Prince and Salzburg. The 3D-models are validated against LiDAR-derived elevation models, population numbers are compared with rastered population data from Statistik Austria. The project explores first steps towards an urban population estimation Service by remote sensing, for the humanitarian community.
Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-l... more Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-like body in the Solar System. After 10 years of ESA’s Mars Express orbiting the planet its High Resolution Stereo Camera (HRSC) covered about 90 % of the surface in stereo and color with resolutions up to 10 m/pixel [1]. Digital elevation models of up to 50 m grid spacing, generated from all suitable datasets of the stereo coverage, currently cover about 40 % of the surface [2]. The geomorphological analysis of surface features, observed by the HRSC indicate major surface modifications by endogenic and exogenic processes on all scales. Endogenic landforms (e.g., tectonic rifts, small basaltic shield volcanoes) were found to be very similar to their equivalents on Earth [1,3,4,5,6,7], suggesting that no unique processes are required to explain their formation. Volcanism may have been active up to the very recent past or even to the present, putting important constraints on thermal evoluti...
Damage assessment is a crucial aspect in many different fields, especially in the humanitarian co... more Damage assessment is a crucial aspect in many different fields, especially in the humanitarian context. Often the estimation is in addition time critical as conflict events urge a quick response from NGOs. The presented approach is part of a currently ongoing research project analyzing the potential of cross-stereo satellite imagery, i.e. images from different dates of the same or even different satellite sensors, to allow the generation of pre and post-event 3D information also in situations with difficult data constellations. This 3D information may be used for change detection, damage assessment, and even population estimation based on building height derivation. The study area is located in the city of Mosul, Iraq. The city has been attacked several times and has been seriously damaged, in particular in June and July 2017. A regular Pleiades-tri-stereo optical satellite image of May 6, 2015 was available as pre-event dataset, and a mixed/cross stereo pair of two (mono) Pleiades ...
The region between Terra Cimmeria and Terra Sirenum contains several fields of enigmatic knobs, i... more The region between Terra Cimmeria and Terra Sirenum contains several fields of enigmatic knobs, in-cluding Ariadnes Colles, Atlantis Chaos and Gorgo-num Chaos. They have been mapped as Hesperian or Amazonian units [1,2] and are located within the shoreline of the Eridania Lake, which might have formed Ma’adim Vallis [3]. The knob fields contain Mg/Fe-rich and locally Al-rich phyllosilicates [5,6, this study]. Following the stratigraphic placement by [1,2], the knobs are younger than the Noachian, in a possible disagreement to [4]. The region also features chloride deposits [7] and valley networks younger than the Hesperian ridged plains (Hr unit [1,2]), named Mid-Latitude Valleys (MLV) by [8], and has been proposed as an MSL landing site by [9]. The knob fields have been mapped by [10] as "surface type 4" of a possible airfall deposit informally named "Electris deposit", which covers the Hesperian ridged plains and cratered uplands. A recent study by [6], suggest...
Introduction: To outline Martian surface units, one approach is to use morphologic and textural f... more Introduction: To outline Martian surface units, one approach is to use morphologic and textural features identified in panchromatic imagery. These datasets provide high spatial resolution and coverage, but convey only indirect information about the mineral composition of the surface materials. On the other hand, imaging spectrometers like the Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) or the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) are very well suited instruments to determine the surface mineral composition, but have only a limited spatial resolution (350 m to 4 km for OMEGA) or coverage (1% of the surface of Mars for CRISM targeted observations. In this study, we investigate the potential of the color dataset of the High Resolution Stereo Camera (HRSC) onboard Mars Express to bridge this gap.
Zusammenfassung: Zur Versorgung von Flüchtlingslagern mit Trinkwasser benötigen humanitäre Hilfso... more Zusammenfassung: Zur Versorgung von Flüchtlingslagern mit Trinkwasser benötigen humanitäre Hilfsorganisationen wie Ärzte ohne Grenzen eine effiziente hydrogeologische Bewertung. Im Projekt EO4HumEn werden dafür Methoden auf Basis von Fernerkundungsdaten entwickelt. Je nach Aquifertyp (Porenaquifer/Kluftaquifer) stehen unterschiedliche Fragen im Fokus. Für Porenaquifere ist die Kartierung von Sandund Tonkörpern, Gewässernetz und Quellhorizonten anhand von Vegetation und Bodenfeuchte von besonderem Interesse. Für Kluftaquifere soll ein Algorithmus zur automatischen Extraktion von Lineamenten mit Hilfe von objekt-basierter Bildanalyse entwickelt werden. Grundlage sind Daten der Sensoren Landsat, ASTER und TerraSAR-X. Die Ergebnisse werden an ausgewählten Standorten validiert und sind Ausgangspunkt für weitergehende Untersuchungen im Gelände.
We describe an image-comparison technique of Heidemann and Ritter [4,5] that uses image compressi... more We describe an image-comparison technique of Heidemann and Ritter [4,5] that uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously-observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coalbeds. Some of the rocks are partly covered with lichen. The imagematching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving a 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of diff...
Earth-observation-based mapping plays a critical role in humanitarian responses by providing time... more Earth-observation-based mapping plays a critical role in humanitarian responses by providing timely and accurate information in inaccessible areas, or in situations where frequent updates and monitoring are required, such as in internally displaced population (IDP)/refugee settlements. Manual information extraction pipelines are slow and resource inefficient. Advances in deep learning, especially convolutional neural networks (CNNs), are providing state-of-the-art possibilities for automation in information extraction. This study investigates a deep convolutional neural network-based Mask R-CNN model for dwelling extractions in IDP/refugee settlements. The study uses a time series of very high-resolution satellite images from WorldView-2 and WorldView-3. The model was trained with transfer learning through domain adaptation from nonremote sensing tasks. The capability of a model trained on historical images to detect dwelling features on completely unseen newly obtained images throu...
Satellite imagery is an important information source for research on remote sensing (RS)based hum... more Satellite imagery is an important information source for research on remote sensing (RS)based humanitarian applications. The selection of satellite imagery is one of the most important steps for such research. This paper firstly shows the selection of satellite imagery in past research from 2015 to 2021. It can be found that most research on land cover and land use (LCLU) change caused by conflicts or refugees/internally displaced persons (IDPs) chose medium spatial resolution (MSR) imagery. Most research on dwelling detection of refugee/IDP camps applied high or very high spatial resolution (HSR/VHSR) imagery. There is much research that applied multiple types of satellite imagery for humanitarian applications. Then, the paper presents general characteristics of commonly available optical satellite imagery. Next, with the development of sensors, this paper suggests that data fusion of SPOT5 and Sentinel-2 may be helpful in LCLU change detection caused by refugees/IDPs or conflicts....
Introduction: Juventae Chasma, north of Valles Marineris on Mars contains several light-toned dep... more Introduction: Juventae Chasma, north of Valles Marineris on Mars contains several light-toned deposits (LTD). The four most prominent ones have been informally labeled A – D by [1]. They were interpreted as the result of sub-ice volcano eruptions [1]. More recently , [2] suggested a formation of these and other LTD's on Mars as spring deposits. This work focuses on the mineral composition of mound B, located at 297.7 E,-4.4 N. It has an extension of about 25km in length and 10 km in width. It rises from 2800 m to 266 m below datum. Two stratigraphic units can be identified in HRSC image data: a lower unit, consisting of an alteration of light and dark toned layers with thicknesses roughly ten meters, and an upper unit with layer thicknesses of approximately 100 m, estimated from an HRSC digital terrain model. The mineralogy of this outcrop was investigated by [3] based on IR data from the imaging spectrometer Observatoire pour l'Eau, les Glaces et l'Activité (OMEGA) on M...
Critical information on refugee/internally displaced people (IDP) camps can be provided to humani... more Critical information on refugee/internally displaced people (IDP) camps can be provided to humanitarian organisations to support planning of emergency response and relief using multi-temporal and multi-scale information from satellite imagery and GIS data. Since 2011 we are providing Earth observationbased information services to Médecins Sans Frontières (MSF) on demand. A service on population monitoring has already reached an operational stage. Thereby indicators on population are derived by automated dwelling extraction from (multi-temporal) very high resolution (VHR) satellite imagery. Based on such information, further added-value products are provided to analyse internal camp structure or camp evolution. Two additional services to support groundwater extraction and assess the impact of the camps on the environment are currently under development. So far twenty-five sites in nine countries have been analysed and more than a hundred maps were provided to MSF and other humanitari...
Introduction: We present results of our study of the sulfates and iron oxides in Ophir Chasma, Ma... more Introduction: We present results of our study of the sulfates and iron oxides in Ophir Chasma, Mars, using visible to short wave infrared data (SWIR) from the imaging spectrometers OMEGA and CRISM in conjunction with panchromatic and color imagery, digital elevation models and anaglyphs. Similar studies of the mineralogy of the light-toned deposits (LTD) in Valles Marineris on Mars have been presented by [1-12].
In the project X3D4Pop we investigate if "mixed" satellite image pairs acquired on two ... more In the project X3D4Pop we investigate if "mixed" satellite image pairs acquired on two different dates can be used to calculate meaningful building heights in urban areas. Based on These results, the dependency of urban population estimation models on the availability and quality of 3D data is tested. Study areas are Port-au-Prince and Salzburg. The 3D-models are validated against LiDAR-derived elevation models, population numbers are compared with rastered population data from Statistik Austria. The project explores first steps towards an urban population estimation Service by remote sensing, for the humanitarian community.
Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-l... more Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-like body in the Solar System. After 10 years of ESA’s Mars Express orbiting the planet its High Resolution Stereo Camera (HRSC) covered about 90 % of the surface in stereo and color with resolutions up to 10 m/pixel [1]. Digital elevation models of up to 50 m grid spacing, generated from all suitable datasets of the stereo coverage, currently cover about 40 % of the surface [2]. The geomorphological analysis of surface features, observed by the HRSC indicate major surface modifications by endogenic and exogenic processes on all scales. Endogenic landforms (e.g., tectonic rifts, small basaltic shield volcanoes) were found to be very similar to their equivalents on Earth [1,3,4,5,6,7], suggesting that no unique processes are required to explain their formation. Volcanism may have been active up to the very recent past or even to the present, putting important constraints on thermal evoluti...
Damage assessment is a crucial aspect in many different fields, especially in the humanitarian co... more Damage assessment is a crucial aspect in many different fields, especially in the humanitarian context. Often the estimation is in addition time critical as conflict events urge a quick response from NGOs. The presented approach is part of a currently ongoing research project analyzing the potential of cross-stereo satellite imagery, i.e. images from different dates of the same or even different satellite sensors, to allow the generation of pre and post-event 3D information also in situations with difficult data constellations. This 3D information may be used for change detection, damage assessment, and even population estimation based on building height derivation. The study area is located in the city of Mosul, Iraq. The city has been attacked several times and has been seriously damaged, in particular in June and July 2017. A regular Pleiades-tri-stereo optical satellite image of May 6, 2015 was available as pre-event dataset, and a mixed/cross stereo pair of two (mono) Pleiades ...
The region between Terra Cimmeria and Terra Sirenum contains several fields of enigmatic knobs, i... more The region between Terra Cimmeria and Terra Sirenum contains several fields of enigmatic knobs, in-cluding Ariadnes Colles, Atlantis Chaos and Gorgo-num Chaos. They have been mapped as Hesperian or Amazonian units [1,2] and are located within the shoreline of the Eridania Lake, which might have formed Ma’adim Vallis [3]. The knob fields contain Mg/Fe-rich and locally Al-rich phyllosilicates [5,6, this study]. Following the stratigraphic placement by [1,2], the knobs are younger than the Noachian, in a possible disagreement to [4]. The region also features chloride deposits [7] and valley networks younger than the Hesperian ridged plains (Hr unit [1,2]), named Mid-Latitude Valleys (MLV) by [8], and has been proposed as an MSL landing site by [9]. The knob fields have been mapped by [10] as "surface type 4" of a possible airfall deposit informally named "Electris deposit", which covers the Hesperian ridged plains and cratered uplands. A recent study by [6], suggest...
Introduction: To outline Martian surface units, one approach is to use morphologic and textural f... more Introduction: To outline Martian surface units, one approach is to use morphologic and textural features identified in panchromatic imagery. These datasets provide high spatial resolution and coverage, but convey only indirect information about the mineral composition of the surface materials. On the other hand, imaging spectrometers like the Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) or the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) are very well suited instruments to determine the surface mineral composition, but have only a limited spatial resolution (350 m to 4 km for OMEGA) or coverage (1% of the surface of Mars for CRISM targeted observations. In this study, we investigate the potential of the color dataset of the High Resolution Stereo Camera (HRSC) onboard Mars Express to bridge this gap.
Zusammenfassung: Zur Versorgung von Flüchtlingslagern mit Trinkwasser benötigen humanitäre Hilfso... more Zusammenfassung: Zur Versorgung von Flüchtlingslagern mit Trinkwasser benötigen humanitäre Hilfsorganisationen wie Ärzte ohne Grenzen eine effiziente hydrogeologische Bewertung. Im Projekt EO4HumEn werden dafür Methoden auf Basis von Fernerkundungsdaten entwickelt. Je nach Aquifertyp (Porenaquifer/Kluftaquifer) stehen unterschiedliche Fragen im Fokus. Für Porenaquifere ist die Kartierung von Sandund Tonkörpern, Gewässernetz und Quellhorizonten anhand von Vegetation und Bodenfeuchte von besonderem Interesse. Für Kluftaquifere soll ein Algorithmus zur automatischen Extraktion von Lineamenten mit Hilfe von objekt-basierter Bildanalyse entwickelt werden. Grundlage sind Daten der Sensoren Landsat, ASTER und TerraSAR-X. Die Ergebnisse werden an ausgewählten Standorten validiert und sind Ausgangspunkt für weitergehende Untersuchungen im Gelände.
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