Improve OSSE 2020a Exp

Need to improve each of the scripts for the OSSE 2020a experiment using the neural fields method.

Task List:
- [ ] Create function to take in config, generate coords, generate dataset (e.g. duacs size, 4dvar size, natl60 size)
- [ ] Create evaluation script to reproduce data challenge repo.
- [ ] Create inference script
- [ ] Create viz script with
- [ ] Create interactive viz script
- [ ] Add download script from alti-tools
- [ ] Add preprocess script from alti-tools
- [ ] Add higher order physics, eg relative vorticity, abs velocity