Radiometric block adjustment with GENA

First results of radiometric block adjustment and digital radiometric model (DRM) generation have been presented in a joint article by the Institute of Geomatics (IG) and the company ALTAIS at the ISPRS Hannover Workshop 2013 held in Hannover (Germany).

In the article, a rigorous concept for radiometric block adjustment is described. The concept is based on atmospheric radiative transfer (ART) models, pre-selected bidirectional reflectance distribution function (BRDF) models (the Beisl-Woodhouse BRDF) and radiometric ground control points. The concept for a terrain's digital radiometric model (DRM) and its generation is also described. (A DRM is a model that provides the reflectance value and the BRDF of each ground point.)

Besides the mathematical models, the article reports on a validation experiment with a block acquired with the UltraCam Xp Wide Angle S/N UC-SXpwa-50814031 camera. The block consisted of 337 images, 4764 radiometric tie points and 21577 radiometric image measurements. The unnoticeable seam lines of orthophoto mosaics, the precision of the radiometric image measurements (0.04 [0,1]-normalized DN), the low bias and moderate accuracy at the radiometric ground check points (0.02 and 0.17 [0,1]-normalized DN respectively) are encouraging preliminary results.

The radiometric block adjustment was performed with GENA and the mathematical models were developed by a team of the IG and ALTAIS.

GENA (Generic Extensible Network Approach) is GeoNumerics' robust non-linear least-squares generic network adjustment engine. With GENA, measurements of geodetic networks, photogrammetric and remote sensing blocks can be adjusted. Observations of different types can be arbitrarily combined into single large adjustments for model-based parameter estimation purposes. GENA has been used for geometric and radiometric modelling from terrestrial and aerial surveys, ranging from LiDAR to thermal sensing, to optical camera prototyping. GENA has been also used for gravity anomaly determination in kinematic INS/GNSS gravimetry.

The International Society for Photogrammetry and Remote Sensing (ISPRS) is a non-governmental organization devoted to the development of international cooperation for the advancement of photogrammetry and remote sensing and their applications. The Society operates without any discrimination on grounds of race, religion, nationality, or political philosophy. The ISPRS was founded in 1910 by its first President, Eduard Dolezal, under the name International Society for Photogrammetry (ISP) that was extended to ISPRS in 1980.

The Institut für Photogrammetrie und GeoInformation (IPI) of the Leibniz Universität Hannover (Hannover, Germany) organizes the "ISPRS Hannover Workshop" on a biennial basis on behalf of the ISPRS.

ARTICLE DETAILS

Authors: Pros,A.,Colomina,I.,Navarro,J.A.,Antequera,R.,Andrinal,P.
Year: 2013
Title: Radiometric block adjustment and digital radiometric model generation
Book: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 40(1-W1)
Pages: 293-298
Conference:  ISPRS Hannover Workshop 2013
Organization: ISPRS
Venue: Institut für Photogrammetrie und GeoInformation, Leibniz Universität Hannover, Hannover, Germany

ARTICLE CITATION

Pros,A.,Colomina,I.,Navarro,J.A.,Antequera,R.,Andrinal,P., 2013. Radiometric block adjustment and digital radiometric model generation. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 40(1-W1), pp. 293-298.

ARTICLE DOWNLOAD

The article may be downloaded here.