Virtual SPICE Training for BepiColombo, July 21-22, 2020
In this lesson you will develop a series of simple programs that demonstrate the usage of SpiceyPy to compute a variety of different geometric quantities applicable to experiments carried out by BepiColombo MPO during the first Venus swingby.
You may find it useful to consult the permuted index, the headers of various source modules, and several Required Reading documents available at the NAIF site.
First of all exercise the usage of WebGeocalc by finding the closest approach of BEPICOLOMBO MPO to Venus. Use the ESA SPCIE Service WebGeocalc instance for this purpose.
Start SPICE-enhanced Cosmographia and load the BepiColombo Scenario. Then choose the time of the Venus Closest Approach for the first Venus Swingby and display the MPO-Venus distance, does it correspond to the distance that you have obtained with WebGeocalc and with your program?
You can also use the public instance of SPOT to visualize the first Venus swingby, you can access it from here: http://bepicolombo.esac.esa.int/itl-viewer/venus_flyby_1/, is the distance the same as well?
Using SPOT access "Sensors FoV" and activate "MERTIS_TIR" then click on "View", you will now see the visualization using a view direction parallel to the MERTIS TIR Field-of-View, use the time slider to check when Venus will be in the Field-of-View.
Afterwards using Cosmographia, load the MERTIS TIR sensor configuration file (on top of the appropriate BepiColombo scenario) and try to replicate the same view-point in the same way that it has been shown during the WebGeocalc and Cosmographia lecture.
Write a program given an input UTC time string that computes the intersection of the MPO MERTIS TIR
boresight and field of view (FOV) boundary vectors with the surface of Mercury.
The program presents each point of intersection as
For each of the sensor FOV boundary and boresight vectors, if an intersection is found, the program displays the results of the above computations, otherwise it indicates no intersection exists.
Use this program to compute values at the following times:
Can you explain the different results?
Compute the time intervals when Venus is visible by the MERTIS_TIR_SPACE Field-of-View in the time frame of the first Venus swingby using the Geometry Finder Sub-System. Print the resulting time windows. If you feel lost you might find it useful to search for documentation either in the header of the corresponding SPICE API or in the documentation of SpiceyPy: https://spiceypy.readthedocs.io/en/master/event_finding.html
Double-check you results with WebGeocalc and with Cosmographia and/or SPOT, do you see any differences? If so, can you explain why?
One of the latest features added to the BepiColombo SPICE Kernel Dataset is the possibility to compute the intervals when the Solar Electrical Propulsion is ON. This is not a straightforward computation with SPICE nor you have the kernels available in the GitHub repository, therefore in order to do so follow these steps: