ESF Thüringen - Liste der Vorhaben Förderperiode 2014-2020

moses II - Magneto-optical sensor system II

Forensic analysis of magnetic tape technology

moses II is a magneto-optical readout system for forensic investigations. It enables a quick and reliable visualization of the magnetic tape information. Based on the modular design MOSES II supports the investigation of all types of commercially available tapes.


moses 2

Magneto-optical forensic visualization

Magnetic fields can be found on all magnetic information carriers such as credit cards and audio- & video tapes. This magnetic information unfortunately can be easily copied and manipulated.

EHowever, there always remains manipulation traces which can be visualized moses II. These traces for instance occur due to the mismatch or the tilting of the audio head, that produces the traces while writing. Another reason for traces are  typical touchdown and lift off marks of the audio head.


Functional principle

  • Generation of homogeneous, linear polarized light (LED + polarizing filter)
  • Change of the polarization status and reflection of light in the magneto-optical sensor dependent on the applied local magnetic field
  • Visualization of the generated inhomogeneous polarization of the light as a local intensity alteration via a second polarizer
  • Recording of the magneto-optical image by using a digital camera on request

Technical features

Direct visualization of magnetic information


Monochromatic LED light source


Highly sensitive magneto-optical sensor (at least 17 x 8 mm)


Manually adjustable analyzer  
High resolution color CCD camera with zoom lens  
Software for camera control and image processing  
Audio output connector & integrated speakers  
Modules for compact- and micro-cassettes as well as for video tapes