some bins values are two-dimensional

[jvandegriff]

The data description here:

https://pds-ppi.igpp.ucla.edu/ditdos/viewFile?id=pds://PPI/maven.swea.calibrated/data/arc_3d/2014/03/mvn_swe_l2_arc3d_20140320_v04_r01.xml

is for MAVEN SWEA raw plasma data, which is basically like energetic particle data

It has a parameter diff_en_fluxes which is a 3 dimensional parameter (4 if you count time, but HAPI captures this as 3-D). It has intensity versus elevation(6), azimuth(16), and energy(64).

size=[ 6,16,64] (elev, azim, energy)

The azimuth and energy bins are each 1-D, but the elevation bins are 2-D. So there are 6 different elevation bin centers for each of the 64 energies.

Is it worth having multi-dimensional bins?
How common is this?
Could this data be represented any other way that HAPI can capture?

[jvandegriff]

CDAWeb some datasets like to too (MAVEN like the above example) and others with multi-dimensional bin descriptions with also time varying aspects.

Links to issues #82 and #83 - maybe these will address this too.

[jvandegriff]

Jeremy says there are Parker Solar Probe datasets from ISOIS/EPI-Lo that have similar dimensionality and variation of the bins.

[jvandegriff]

TODO: get the PSP EPI-Lo data and see how it would look;
one thing to consider is if the 2D values are not time varying - is there a way to capture that statically in the info header?

[jbfaden]

Jon and I talked about this today and I'll set up a demo dataset that is similar to the MAVEN data, containing non-time-varying but multidimensional depend data.

I have an example of time-varying multidimensional depend data, see https://jfaden.net/HapiServerDemo/hapi/info?id=rank3dep2

[jvandegriff]

Need to develop a convention that's consistent with the way label and units varieties are expressed.

We need examples to clarify and then can decide what's the best way to account for this and also to capture it's description in the spec.

Would be good to build off existing examples, i.e., show after the time-varying case (show one where the pitch angles change as a function of energy, for example).

[jbfaden]

mvn_swi_l2_coarsearc3d_20140320_v01_r00.skt