1.  The original idea behind ASF.

Science requirements for the study of the kinematics and dynamics of arctic sea ice indicated a need for routine, high resolution imaging of the Arctic day and night and under all weather conditions.

2.  The Solution

Solution was to construct a facility to acquire real time downlinked SAR data and achieve maximum reach over the Arctic Ocean.  The facility consisted of a receiving ground station, a sar processing system, and a data archive.  Those systems were designed to acquire and process about 8 minutes of SAR data per day.

3.  The result

ASF construction began in 1985 and was completed by 1987.  In 19?? ASF received the first SAR images from the ERS-1 Satellite.  During the next several years, scientific accomplishments included .......

4.  New satellites and new acquisition and processing facilities.

The success of science activities using data from ASF and ASF's high latitude made it uniquely suited to data downlinks from polar orbiting satellites, encouraged NASA to expand ASF activities to include data from additional satellites.  These were Satellite X in Year Y etc.  Data acquisitions required the addition of a second antenna, improved Receiving equipment, and an upgraded archive.  The expanding temporal, spatial and frequency coverage facilitated new science.  Science highlights included .........

5.  Global coverage

With the launch of the Japanese JERS-1 and the Canadian Radarsat, US investigators achieved global access through data acquired at the ASF.  This advance enabled important new, large scale programs to study the Antarctic, the Boreal Forest and the Amazon.  Scientiifc results included  .  The increased data flow drove the development of the precision processor and improved archiving.

6.  The Current Situation

ASF is uniquely suited for acquistion of SAR data acquired anywhere in the world.  It has a high volume processor capable of producing calibrated images at a rate of 1 per year (just kidding!).  It has an improved archive and data distribution system.  It will soon have capability to distribute level zero data (the delays here are becoming a problem).  With this capability, we envision the future of ASF to be driven by the selective acquirisition and processing of SAR to meet the science requirements of the research community over the next 5 years (THIS IS A POLICY ISSUE, IS ASF CHARTERED TO DO SELECTIVE OR ROUTINE ACQUISITIONS AND PROCESSING.  What happens when ASF is asked to collect data from non-SAR satellites).

7.  The next 5 years

Global Reach for Scientific Research

Because ASF is an integrated system from acquisition to distribution, it is uniquely suited to the production of large volume, thematic data sets collected anywhere in the world.  System integration provides unparalleled reliability that is simply not achievable by distributed systems (such as ESA's).  A good example is the reliability constraint imposed by a program like ramp which required 99.9% acquistion reliability, verification, and preliminary processing all within a 30 day window of opportunity.

For that reason, we envision requirements over the next 5 years.  Insert A bunch of requirements and the relationships to ESE objectives.  These lead to projects which include RAMP 2, Boreal Forest 2, Amazon 2, RGPS 2 etc.  A point here is which satellites will be used.  You don't need every satellite to do every one of these jobs. Aonther way to say it is which satellite is best suited to a particular science objective.  Consequently, I think ASF should only acquire data which is directly in support of a science activity.

Routine Production of Level Zero data for InSAR

InSAR is clearly the most exciting application with the greatest potential over the next 5 years.  ASF is pursuing distribution of level zero data - but the process is slow.  Maybe a goal here could be defining how Level Zero data could be made quickly available (months) and how over the next two years.  Maybe there are some objectives that can make ASF uniquely suited to serving the INSAR community.

Customized Processing for the Small User

Non-SAR experts will still have a high interest in value added SAR products (terrain correction, geolocation etc).  A good example if the ADRO program.  Successes of ADRO include blah blah blah.

In anticipation of programs like ADRO-2, ASF could be expected to meet a variety of objectives (maybe culled from the 1995 SAR report prepared by JPL).  I think the trick here is devising a strategy that fulfills science requirements without pulling down every bit of  data from every satellite that is in orbit.  I really think we got into trouble by mixing the roles of a scientific and a service/operational facility.

8.  Implications on ASF development and operation

Tracebility matrix between exisiting and planned ASF functionalities and Science Requirements

Anticipated data volumes by Satellite

ASF and EOSDIS

ASF and UAF

ASFUWG