http://docs.opengeospatial.org/is/16-120r3/16-120r3.html#12 defines three types of functions:

• Type A: Retrieval of feature attribute
• Type B: Operations between one trajectory object and one or more geometry objects
• Type C: Operations between two trajectory objects

• Basic use case with QFU change and go-around
• Algorithms: particle model for wind field here
• Basic introduction on Enhanced Mode S (with link to https://mode-s.org/)
• Command line tool

How about summing the contribution of different readers to the same variable, at least for currents?
For example, different components of the current (ekman, stokes, geostrophic, tide, ...) may be stored in different files that are not on the same grid. Summing the component at read time can prevent a regridding preprocessing of files.

in calculating the Trajectories:

• The command option --out should be modified to be the output file prefix.
  If I uses this --out traj.txt, it creates a file with the term as a prefix, but still adds the trajectory.txt to create a file named traj.txt_trajectory.txt

Calculating the trajectory trends:

• some options

since I have succed singularity pull shub://dynverse/ti_slingshot:latest, but when I run model <- infer_trajectory(dataset, "slingshot"), it showed me Running singularity exec 'docker://dynverse/ti_slingshot:v1.0.3' echo hi.

what should I do to set singularity run image from shub://dynverse/

Adapt the haversine distance function to support two arrays of locations as input, so that the paired distances are computed similarly to how the Euclidean distance works.