Generation and Quality Assessment of Stereo-Extracted DSM From GeoEye-1 and WorldView-2 Imagery

Saldaña

European Journal of Remote Sensing

et al. 2014

A comparison between GeoEye-1 (Geo format) and WorldView-2 (Basic and Ortho Ready Standard format) multispectral (MS) imagery regarding both geometric and radiometric characteristics was carried out over the same study area. Firstly, the attainable geopositioning accuracies on seven single MS images from both very high resolution sensors were compared in the same conditions, both along the sensor orientation and orthorectification phase. The orthoimages planimetric accuracy was ranging from 1.86 m to 2.22 m. The best results were achieved in the case of GeoEye-1 MS orthoimages, nearly followed by those coming from WorldView-2 ones. Secondly, and regarding the radiometric characteristics of the both MS sensors tested, a higher digital numbers' histogram compression in the case of WorldView-2 was found in the four common bands shared by both MS sensors, especially in the blue band. A no-reference assessment of image quality by using blur ratio was also computed in order to attain image sharpness metric. The blur ratio presented slightly lower values for the GeoEye-1 images.

Section: Radiometric Characteristicssupporting

confidence: 52%

Section: Radiometric Characteristicsmentioning

confidence: 94%

Comparing geometric and radiometric information from GeoEye-1 and WorldView-2 multispectral imagery

Saldaña

European Journal of Remote Sensing

et al. 2014

“…However, it should be noted that the canopy surface represented may not represent the tallest tree. The vertical and horizontal accuracies of these models are related primarily to the convergence angle formed from the sensor-target geometry of the acquisition of the stereo image pairs [59][60][61]. The utility of the convergence angles in determining the accuracy of short feature height measurements (such as small trees) is an on-going line of inquiry.…”

Section: Introductionmentioning

confidence: 99%

The Uncertainty of Plot-Scale Forest Height Estimates from Complementary Spaceborne Observations in the Taiga-Tundra Ecotone

et al. 2014

Satellite-based estimates of vegetation structure capture broad-scale vegetation characteristics as well as differences in vegetation structure at plot-scales. Active remote sensing from laser altimetry and radar systems is regularly used to measure vegetation height and infer vegetation structural attributes, however, the current uncertainty of their spaceborne measurements is likely to mask actual plot-scale differences in vertical structures in sparse forests. In the taiga (boreal forest)-tundra ecotone (TTE) the accumulated effect of subtle plot-scale differences in vegetation height across broad-scales may be significant. This paper examines the uncertainty of plot-scale forest canopy height measurements in northern Siberia Larix stands by combining complementary canopy surface elevations derived from satellite photogrammetry and ground elevations derived from the Geosciences Laser Altimeter System (GLAS) from the ICESat-1 satellite. With a linear model, spaceborne-derived canopy height measurements at the plot-scale predicted TTE stand height ~5 m-~10 m tall (R 2 = 0.55, bootstrapped 95% confidence interval of R 2 = 0.36-0.74) with an uncertainty ranging from ±0.86 m-1.37 m. A larger sample may mitigate the broad uncertainty of the model fit, however, the methodology provides a means for capturing plot-scale canopy height and its uncertainty from spaceborne data at GLAS footprints in

International Journal of Remote Sensing

“…At present, as a matter of fact, there is a huge literature about the DSMs generation from high resolution optical satellite imagery (Habib et al 2004;Jacobsen 2006;Toutin 2006aToutin , 2006bZhang and Gruen 2006;Büyüksalih and Jacobsen 2007;Alobeid and Jacobsen 2008;d'Angelo et al 2008;Crespi et al 2010;Capaldo, Crespi, Fratarcangeli, Nascetti, and Pieralice 2012;Dowman et al 2012;Aguilar et al 2014;Reinartz et al 2014;Gong and Fritsch 2016;Ghuffar 2016, etc. ), and for some years there are different commercial and scientific software able to process high resolution satellite optical imagery and to generate DSMs, amongst which the well known PCIGeomatica, ENVI (software, as PCI-Geomatica and SAT-PP), and SAT-PP.…”

Section: Introductionmentioning

confidence: 99%

Open source tool for DSMs generation from high resolution optical satellite imagery: development and testing of an OSSIM plug-in

Rita

Nascetti

Crespi

2017

The fully automatic generation of digital surface models (DSMs) is still an open research issue. From recent years, computer vision algorithms have been introduced in photogrammetry in order to exploit their capabilities and efficiency in three-dimensional modelling. In this article, a new tool for fully automatic DSMs generation from high resolution satellite optical imagery is presented. In particular, a new iterative approach in order to obtain the quasi-epipolar images from the original stereopairs has been defined and deployed. This approach is implemented in a new Free and Open Source Software (FOSS) named Digital Automatic Terrain Extractor (DATE) developed at the Geodesy and Geomatics Division, University of Rome 'La Sapienza', and conceived as an Open Source Software Image Map (OSSIM) plug-in. DATE key features include: the epipolarity achievement in the object space, thanks to the images ground projection (Ground quasi-Epipolar Imagery (GrEI)) and the coarse-to-fine pyramidal scheme adopted; the use of computer vision algorithms in order to improve the processing efficiency and make the DSMs generation process fully automatic; the free and open source aspect of the developed code. The implemented plug-in was validated through two optical datasets, GeoEye-1 and the newest Pléiades-high resolution (HR) imagery, on Trento (Northern Italy) test site. The DSMs, generated on the basis of the metadata rational polynomial coefficients only, without any ground control point, are compared to a reference lidar in areas with different land use/land cover and morphology. The results obtained thanks to the developed workflow are good in terms of statistical parameters (root mean square error around 5 m for GeoEye-1 and around 4 m for Pléiades-HR imagery) and comparable with the results obtained through different software by other authors on the same test site, whereas in terms of efficiency DATE outperforms most of the available commercial software. These first achievements indicate good potential for the developed plug-in, which in a very near future will be also upgraded for synthetic aperture radar and tri-stereo optical imagery processing. ARTICLE HISTORY