As I interpret @marqh 's suggestion, the point is to loosen the requirement for coordinates. The goal is that coordinates for every data point in a data set should be reconstructable, if not explicitly encoded in the data.
To be honest, I think we might be able to do this with the existing text without endangering data integrity. For the use case in question, satellite producers (such as EUMETSAT) would like to be able to: - Provide coordinates for groupings of views, called *fields of regard (FORs)*. These FORs contain *fields of view (FOVs)* which represent individual data points. - Provide enough information to be able to *reconstruct* the position of each FOV within the FOR, without providing coordinates for each FOV. This would save a lot of space. Now to the actual requirements (I'm adding emphasis): - CF 1.7, 5.6, paragraph 1, sentence 1: "When the coordinate variables *for a horizontal grid* are not longitude and latitude, it is required that the true latitude and longitude coordinates be supplied via the `coordinates` attribute." If we understand our horizontal grid to refer to the grid of FORs, this is already fulfilled. There's no requirement that every data point have coordinates here. - CF 1.7, 5, paragraph 2, sentence 1: "Any of a variable's dimensions *that is an independently varying latitude, longitude, ... dimension* ... must have a corresponding coordinate variable." Here also, we could be weasley with our satellite data by claiming that the FOVs vary *dependently* of the FORs, and therefore they don't need their own coordinate variable. Please correct me if this is overly naive, but maybe the better approach would be to provide an example in one of the appendices, rather than change the text of the convention. -- You are receiving this because you commented. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/pull/133#issuecomment-408439318
