What is a desktop survey?
Your reseller may carry out a desktop survey to determine who the best carrier in your country for your specific location . They will check what coverage is available from each carrier and also look at the topography of your location . Using that information they can decide which data SIM will be to be the most suitable option for you.
It’s called a ‘desktop’ survey as it is done remotely. Your reseller may use these as an alternative to physically carrying out a survey in your location.