A Worldwide 3d GCP Database Inherited From 20 Years of Massive Multi-Satellite Observations

Abstract

Abstract. High location accuracy is a major requirement for satellite image users. Target performance is usually achieved thanks to either specific on-board satellite equipment or an auxiliary registration reference dataset. Both methods may be expensive and with certain limitations in terms of performance. The Institut national de l’information géographique et forestière (IGN) and Airbus Defence and Space (ADS) have worked together for almost 20 years, to build reference data for improving image location using multi-satellite observations. The first geometric foundation created has mainly used SPOT 5 High Resolution Stereoscopic (HRS) imagery, ancillary Ground Control Points (GCP) and Very High Resolution (VHR) imagery, providing a homogenous location accuracy of 10m CE90 almost all over the world in 2010.Space Reference Points (SRP) is a new worldwide 3D GCP database, built from a plethoric SPOT 6/7 multi-view archive, largely automatically processed, with cloud-based technologies. SRP aims at providing a systematic and reliable solution for image location (Unmanned Aerial Vehicle, VHR satellite imagery, High Altitudes Pseudo-Satellite…) and similar topics thanks to a high-density point distribution with a 3m CE90 accuracy.This paper describes the principle of SRP generation and presents the first validation results. A SPOT 6/7 smart image selection is performed to keep only relevant images for SRP purpose. The location of these SPOT 6/7 images is refined thanks to a spatiotriangulation on the worldwide geometric foundation, itself improved where needed. Points making up the future SRP database are afterward extracted thanks to classical feature detection algorithms and with respect to the expected density. Different filtering methods are applied to keep the best candidates. The last step of the processing chain is the formatting of the data to the delivery format, including metadata. An example of validation of SRP concept and specification on two tests sites (Spain and China) is then given. As a conclusion, the on-going production is shortly presented.

Co3d, a Worldwide One One-Meter Accuracy Dem for 2025

“…The absolute altimetric requirement is given better than 2 m LE90 for slopes smaller than 5 % and 4 m for higher slopes for 1 m grid spacing DSM. This performance should be reached thanks to the refining of the geometric model on the Space Reference Point (SRP) database, described by Chandelier (2020), and also thanks to bundle-adjustment applied on large set of images. The SRP database GCP accuracy is given better than 3 m CE90 for planimetry and altimetry.…”

The New Landsat Collection-2 Digital Elevation Model

“…The Esri-served WorldDEM consists of the Airbus "WorldDEM4Ortho" data, an automatically generated elevation product created from WorldDEM DSM raw data, which is a hybrid between a DSM and DTM (Digital Surface/Terrain Model) [42,43]. This dataset is served at 0.8 arcsecond (approx.…”

Automated RPCs Bias Compensation for KOMPSAT Imagery Using Orthoimage GCP Chips in Korea

“…Google Maps is often used for georegistration, but its quality has not been proven because it was created for location-based services [19]. As a global reference, Airbus provides chips from stereo synthetic aperture radar (SAR) images and space reference points (SRPs) using SPOT 6/7 data for worldwide coverage [20]. The quality of an SRP that provides a dense chip distribution of at least 1 point per 2 ㎢ is managed with less than 3 meters of positional accuracy (CE90) and 2 meters of ground sampling distance (GSD).…”