Most data sets from Earth observation instruments on satellites will have at least a few gaps that break up the continuity of the data. These gaps can result from satellite or instrument "safeholds", when the satellite was not transmitting data or the instrument was inoperative. Some data gaps result from maneuvers made by the satellite to maintain its orbit or conduct a calibration. Data gaps can also be the result of different observational modes for certain instruments. Data gaps can also occur in multi-satellite data sets when one instrument's data was replaced by another instrument.
This discussion was inspired by a question from a user asking about data gaps in the SeaWiFS ocean color data set. In the next post (to be posted on September 14I will describe a very easy way to see where data gaps are in the SeaWiFS data set. Then we will ask other data scientists and users for their techniques to find and keep track of gaps in the data sets they use.