The Institute for Optical Sensor Systems operates in Berlin-Adlershof in the department Optics, Calibration and Validation (OCV) laboratories for the spectral, radiometric and geometric calibration of optical sensors. The focus is on high-resolution spatial and spectral systems. In addition to complete systems, focal planes and optical components to be investigated. Optical systems are examined in the whole spectral range from (UV) VIS / NIR to TIR. It focuses on the performance analysis, and radiometric and geometric calibration of optical sensors. Performance parameters (e.g. SNR and MTF) provide information on the image quality of the sensor. The radiometric calibration allows converting digital values from the optical system into physical units of radiance. By means of the geometric calibration the viewing angle in the object space are determined for each pixel.
This document describes the optical laboratories and calibration of the Institute for Optical Sensor Systems. In contrast to laboratories where once set up always perform the same measurements and procedures, the specificity of tasks and laboratories in IOS lies in the permanent adaptation to different measurement tasks and new sensors.
A large part of the duties of the department OCV is determined by the participation in various projects and tasks of the Institute. We focus on sensors for Earth observation (WAOSS, MOS, BIRD, Rapid-Eye, ADC, K3, EnMAP), planetary research (Mars Express, MERTIS) and terrestrial applications (panoramic camera).
To provide traceable calibrations, we use calibrated standard references and standard measuring stations as well as methods and measurement specifications for the implementation of the measurement tasks.
Currently, cameras and imaging spectrometers up to 1000 mm focal lengths and about 150mm aperture diameter in the spectral range from 300 nm to about 15 microns (UV, VIS, NIR, SWIR, MIR, TIR), are measured. The weight of the instruments can be up to 100 kg.
OCV provides geometric, spectral and radiometric measurement capabilities, characterization and calibration of detectors and FPA systems to. Examples are like CCD / CMOS line and matrices, bolometer arrays.
The relevant definitions for calibration and validation can be found in
Calibration (ISO 19159-1) (is the) process of quantitatively defining a system’s responses to known, controlled signal inputs [ISO/TS 19101-2]
NOTE: A calibration is an operation that, under specified conditions, in a first step, establishes a relation between indications (with associated measurement uncertainties) and the physical quantity values (with measurement uncertainties) provided by measurement standards.
Validation (ISO 19159-1) (is the) process of assessing, by independent means, the quality of the data products derived from the system outputs
NOTE In this standard the term validation is used in a limited sense and only relates to the validation of calibration data in order to control their change over time. [ISO/TS 19101-2:2008]
Validation (ECSS) (is the) process which demonstrates that the product is able to accomplish its intended use in the intended operational environment
NOTE: Verification is a pre-requisite for validation.
Verification (ECSS) (is the) process which demonstrates through the provision of objective evidence that the product is designed and produced according to its specifications […]
Geometric Calibration Measurement of the MTF and calibration parameter of the optical system. By means of the geometric calibration the viewing angle in the object space can be determined for each pixel.
Radiometric Calibration allows converting digital values from the optical system into physical units of radiance.
The department operates several laboratories: