LISA Technology Package Data Analysis
LTPDA is a freely available MATLAB-based toolbox which we are developing for LISA Pathfinder data analysis. It is highly useful for other data analysis applications as well.
LTPDA is a MATLAB toolbox that is based on the concept of so-called Analysis Objects (AO), which are data structures that not only contain the numerical data but also their complete processing history starting with the raw data. This allows any user with access to the same raw data to reproduce the results either identically or with modified processing parameters and implicitly fulfills stringent documentation requirements. These exist since LTPDA will be used to analyze data as they come in from the satellite in orbit and derive parameters for the next experiments to be uploaded to the satellite. Therefore LTPDA is considered a kind of flight software by ESA and is subject to strict version control and regular comprehensive tests.
An important application of LTPDA are the LTP Mock data challenges which are used to develop and verify the data analysis procedures for LTP (LISA Technology Package). In these exercises two teams are formed from the LTPDA groups. One team generates data as close as possible to the expected data from the satellite, using undisclosed values for the essential parameters to be determined (like stiffness). The second team then tries to recover the parameters. These exercises lead to improvements in the models and algorithms. Closely related to these exercises is the design of the mission time line and experiments to be performed in orbit.