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Using the SPENVIS system

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SPENVIS is a WWW-based instrument intended to facilitate the use of models of the spatial environment in a consistent and structured way. The SPENVIS system consists of an integrated set of models of the space environment, and a set of help pages on both the models and the SPENVIS system itself.

The project concept

At the heart of SPENVIS is the project concept. A project is defined as the collective input to and output from the SPENVIS system for a series of related runs. The physical representation of a project is a subdirectory on the hard drive of the hardware system running SPENVIS. In this subdirectory, all the input parameters are stored, together with all output files generated by the system, until the deletion of the subdirectory (by the user or by the SPENVIS team). This means that all the inputs and the outputs of a run are conserved, so that an analysis can be performed over more than one session, as the results are not lost upon leaving the system. In addition, it is not necessary to re-enter the input parameters already defined in a previous run.

Project operations such as creation, deletion, switching are performed on the project page which can be reached via the project link in the menu bar that appears at the top of each SPENVIS page.

Models implemented in SPENVIS

Most of the models implemented in SPENVIS require as input a set of point on a spacecraft trajectory or a user-defined set of geographic points. These sets of points are produced by two tools: the orbit generator and the coordinate grid generator. In general, one of these tools has to be used before the models themselves can be accessed. SPENVIS Is able to detect whether a spacecraft trajectory or a coordinate grid has been generated: if this is not the case, the system will issue an error message and prompt the user to run the orbit or coordinate grid tool, after which the model in question can be run.

Once a trajectory or a coordinate grid has been generated, it can be used by different models. This means that, in the context of a given project, it is not necessary to generate coordinates for each model separately.

Warning! When running the orbit or grid generator, all outputs previously obtained with models that use the respective coordinate tool, are deleted. This is to ensure consistency between results, and to avoid errors in the plotting routines that produce the graphical output. The input parameters for the models are not deleted, so that they can be run again in the same way.

The models implemented in SPENVIS have been organised in the following packages:

Outputs from the system

SPENVIS Produces two types of output: The Output link in the menu bar at the top of each page points to a page with a list of all output files produced for the active project.

Last update: Wed, 23 Mar 2016