Why do I get records I wasn't expecting when I search?
One of the principles of the VSO is that it's better to return too much data, rather than return too little data.
Although there are measures to ensure that data providers aren't contacted when they are known to not have any data, there may be times when the data provider's catalog doesn't differentiate between some of the facets of the VSO data model. In those cases, the VSO policy is to return all data products that might match.
For instance, if a data provider knows that it has two types of physical observables in its repository, but can't easily differentiate between them, it might serve both types for all requests. (VSO, however, will only contact them when requesting those two physical observables)
Likewise, for range matching, we use the most broad definition of match -- a non-vanishing intersection. As such, a data product's time range or spectral range may not be fully within the time you gave.
If you believe that a data provider is clearly in error (eg, non-intersecting ranges), or would like to suggest particular cases for improvement, the easiest way to show us us the query and subsequent problem records is to do the following:
- Run the query in question
- Select the data products that you believe are in error
- Select 'Add to Shopping Cart'
- Copy the 'Cart ID' that is assigned to your cart.
- Contact us and let us know the nature of the complaint and the Cart ID.