Overview of Data Acquisition Requests (DARs)

As a general rule, a DAR should be placed at least eight weeks prior to the required acquisition date. You should use ASF's web-based DAR tool to submit a request. The web form allows users to specify the satellite, beam/mode, date, time, and other criteria needed to plan a data acquisition. This information is used by ASF's acquisition planners, who will attempt to schedule data acquisitions to meet the request. If you need more flexibility in constructing the area of interest than the DARnet form allows or you want to see possible satellite coverage prior to submitting a DAR please contact ASF User Services.

ASF Users approved for new acquisitions may submit ERS-2 acquisitions within the ASF and McMurdo station masks.

Natural disaster monitoring, or other situations which demand short-notice data acquisitions, require direct interaction and negotiations between the principal investigator and ASF. Please contact User Services if you forsee a need for this type of emergency data acquisition.

Users will be consulted and otherwise notified if there is a problem with their DAR. Acquisitions are normally planned 2-12 weeks prior to the acquisition date, and actually scheduled 1-14 days prior to acquisition. If you require detailed tracking of your DAR please contact ASF User Services for assistance.

Datatakes are not scanned (i.e., do not appear in ASF's data catalog) immediately after they've been acquired. It takes a minimum of three days to obtain sufficiently precise orbit parameters such that scanning and standard processing can be performed.


ERS-2 data acquired at McMurdo are shipped to ASF. Depending upon the season, this can result in data transfer delays of up to nine months.

Unfortunately we can't just submit a DAR and then wait for the finished products to arrive at our offices. Exceptions involve certain near real-time projects, and those arrangements must be made beforehand. (Data acquisitions for near real-time processing are often marked as such; indeed, the original research proposal should mention the need for near real-time data.) Under normal conditions, once the data are scanned and in the ASF catalog, users need to order their SAR products.

Normal processing time is 2 weeks. Users will be informed of any delays in processing their data.