Assessment of Vertical Accuracy for TanDEM-X 90 m DEMs in Plain, Moderate, and Rugged Terrain

Bhardwaj, Ashutosh

doi:10.3390/iecg2019-06208

Cited by 13 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, new freely available global-scale DEM products have been released, such as the TanDEM-X DEM [15], the Multi-Error-Removed Improved-Terrain (MERIT) DEM [21], the ALOS Global Digital Surface Model (AW3D30) [22], and the NASADEM [23]. Because these products are so new (TanDEM-X has been freely available since late 2018, MERIT 2017, AW3D30 and NASADEM since the beginning of 2020), fewer studies have evaluated their accuracy [24][25][26][27][28]. If their accuracy can be confirmed, these new DEM products, which are based on more current remote sensing data and better processing methods, will be highly valuable because of their ability to capture natural or man-made changes in the topography of terrestrial surfaces [29].…”

Section: Introductionmentioning

confidence: 99%

Vertical Accuracy of Freely Available Global Digital Elevation Models (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM)

et al. 2020

View full text Add to dashboard Cite

Freely available global digital elevation models (DEMs) are important inputs for many research fields and applications. During the last decade, several global DEMs have been released based on satellite data. ASTER and SRTM are the most widely used DEMs, but the more recently released, AW3D30, TanDEM-X and MERIT, are being increasingly used. Many researchers have studied the quality of these DEM products in recent years. However, there has been no comprehensive and systematic evaluation of their quality over areas with variable topography and land cover conditions. To provide this comparison, we examined the accuracy of six freely available global DEMs (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM) in four geographic regions with different topographic and land use conditions. We used local high-precision elevation models (Light Detection and Ranging (LiDAR), Pleiades-1A) as reference models and all global models were resampled to reference model resolution (1m). In total, 608 million 1x1 m pixels were analyzed. To estimate the accuracy, we generated error rasters by subtracting each reference model from the corresponding global DEM and calculated descriptive statistics for this difference (e.g., median, mean, root-mean-square error (RMSE)). We also assessed the vertical accuracy as a function of the slope, slope aspect, and land cover. We found that slope had the strongest effect on DEM accuracy, with no relationship for slope aspect. The AW3D30 was the most robust and had the most stable performance in most of the tests and is therefore the best choice for an analysis of multiple geographic regions. SRTM and NASADEM also performed well where available, whereas NASADEM, as a successor of SRTM, showed only slight improvement in comparison to SRTM. MERIT and TanDEM-X also performed well despite their lower spatial resolution.

show abstract

Section: Introductionmentioning

confidence: 99%

Vertical Accuracy of Freely Available Global Digital Elevation Models (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM)

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The vertical accuracy of the 12 m TanDEM-X DEM product has been assessed using ICESat points [70], GPS ground truth values, and LiDAR observed values [76]-or a height error map (HEM) [77] for reference. However, to date, very few studies [78] have been conducted to assess the vertical accuracy of the TanDEM-X 90 m DEM and, particularly, its comparison with other freely available global DEMs [74,79,80].…”

Section: Tandem-x Demmentioning

confidence: 99%

Accuracy Assessment, Comparative Performance, and Enhancement of Public Domain Digital Elevation Models (ASTER 30 m, SRTM 30 m, CARTOSAT 30 m, SRTM 90 m, MERIT 90 m, and TanDEM-X 90 m) Using DGPS

2022

View full text Add to dashboard Cite

Publicly available Digital Elevation Models (DEM) derived from various space-based platforms (Satellite/Space Shuttle Endeavour) have had a tremendous impact on the quantification of landscape characteristics, and the related processes and products. The accuracy of elevation data from six major public domain satellite-derived Digital Elevation Models (a 30 m grid size—ASTER GDEM version 3 (Ast30), SRTM version 3 (Srt30), CartoDEM version V3R1 (Crt30)—and 90 m grid size—SRTM version 4.1 (Srt90), MERIT (MRT90), and TanDEM-X (TDX90)), as well as the improvement in accuracy achieved by applying a correction (linear fit) using Differential Global Positioning System (DGPS) estimates at Ground Control Points (GCPs) is examined in detail. The study area is a hard rock terrain that overall is flat-like with undulating and uneven surfaces (IIT (ISM) Campus and its environs) where the statistical analysis (corrected and uncorrected DEMs), correlation statistics and statistical tests (for elevation and slope), the impact of resampling methods, and the optimum number of GCPs for reduction of error in order to use it in further applications have been presented in detail. As the application of DGPS data at GCPs helps in the substantial reduction of bias by the removal of systematic error, it is recommended that DEMs may be corrected using DGPS before being used in any scientific studies.

show abstract

“…The TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X) departs from an SRTM baseline and provides a new SAR-interferometry-based (synthetic-aperture radar) estimate of elevations globally (Wessel et al, 2018;Zink, 2014). TanDEM-X has been shown to be the most accurate global DEM in some land cover categories (bare, shrub-land, sparse vegetation and urban) (Hawker et al, 2019), and at the 95 % confidence level, Gesch (2018) finds that only TanDEM-X is suitable for delineating the LECZ below 10 m. Wessel et al (2018) found TanDEM-X to have biases in areas of rugged terrain, where there is heterogeneity in the landscape/land cover and elevation, and additional analyses have revealed that while TanDEM-X is highly accurate in flat to slightly undulating terrains, it tends to overestimate elevation when used in areas characterized by more sharply uneven terrain (Bhardwaj, 2019). Higher-resolution versions of TanDEM-X (0.4 and 1 arcsec) are available through proposal and a service fee for scientific use but were not utilized in this study.…”

Section: Tandem-x 90 Mmentioning

confidence: 99%

“…It deviates from the other population data sets in that it aims to measure ambient population -that is, population distribution averaged over a 24 h period, rather than census de jure measures linked to usual residence. LandScan Global is a 30 arcsec population surface which is not directly comparable year over year, since methodologies are updated with each release (Bright and Coleman, 2001;Bright et al, 2016;Rose and Bright, 2014;Mesev, 2003). Thus LandScan is not suitable for use as a time series.…”

Section: Landscanmentioning

confidence: 99%

Estimating population and urban areas at risk of coastal hazards, 1990–2015: how data choices matter

MacManus

Balk

Engin

et al. 2021

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. The accurate estimation of population living in the low-elevation coastal zone (LECZ) – and at heightened risk from sea level rise – is critically important for policymakers and risk managers worldwide. This characterization of potential exposure depends on robust representations not only of coastal elevation and spatial population data but also of settlements along the urban–rural continuum. The empirical basis for LECZ estimation has improved considerably in the 13 years since it was first estimated that 10 % of the world's population – and an even greater share of the urban population – lived in the LECZ (McGranahan et al., 2007a). Those estimates were constrained in several ways, not only most notably by a single 10 m LECZ but also by a dichotomous urban–rural proxy and population from a single source. This paper updates those initial estimates with newer, improved inputs and provides a range of estimates, along with sensitivity analyses that reveal the importance of understanding the strengths and weaknesses of the underlying data. We estimate that between 750 million and nearly 1.1 billion persons globally, in 2015, live in the ≤ 10 m LECZ, with the variation depending on the elevation and population data sources used. The variations are considerably greater at more disaggregated levels, when finer elevation bands (e.g., the ≤ 5 m LECZ) or differing delineations between urban, quasi-urban and rural populations are considered. Despite these variations, there is general agreement that the LECZ is disproportionately home to urban dwellers and that the urban population in the LECZ has grown more than urban areas outside the LECZ since 1990. We describe the main results across these new elevation, population and urban-proxy data sources in order to guide future research and improvements to characterizing risk in low-elevation coastal zones (https://doi.org/10.7927/d1x1-d702, CIESIN and CIDR, 2021).

show abstract

Assessment of Vertical Accuracy for TanDEM-X 90 m DEMs in Plain, Moderate, and Rugged Terrain

Cited by 13 publications

References 17 publications

Vertical Accuracy of Freely Available Global Digital Elevation Models (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM)

Vertical Accuracy of Freely Available Global Digital Elevation Models (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM)

Accuracy Assessment, Comparative Performance, and Enhancement of Public Domain Digital Elevation Models (ASTER 30 m, SRTM 30 m, CARTOSAT 30 m, SRTM 90 m, MERIT 90 m, and TanDEM-X 90 m) Using DGPS

Estimating population and urban areas at risk of coastal hazards, 1990–2015: how data choices matter

Contact Info

Product

Resources

About