Animation of ADAPTS data collection on 6 April 2009. Green and orange dots indicate active beam positions; white dots inactive beam positions. The horizontal axis depicts a 90 deg sector, while the vertical axis depicts the elevation angles. Image courtesy of D. Priegnitz.
Since the spring of 2009, the MPARSUP team has been successfully demonstrating the adaptive scanning capabilites of NSSL's phased-array radar. ADAPTS, which stands for Adaptive Digital Signal Processing Algorithm for PAR Timely Scans, leads to faster updates by performing focused observations. Focused observations provide a means to reduce update times with no sacrifice in data quality or spatial coverage by devoting less radar time to regions of less interest (e.g., clear air), thus reducing the total scan time. The concept of focused observations can be applied to both reflector and phased-array antenna systems; however, a PAR using electronic beam steering is better suited for it since it is not constrained by mechanical inertia.
Detecting regions with significant weather returns is the key for adaptive focused observations. ADAPTS works in real time by classifying individual beam positions within a scanning strategy as active or inactive
A set of questions about the utility of ADAPTS were included in the PARISE 2009 questionnaire. During the experiment, ADAPTS was evaluated by visiting National Weather Service forecasters for the first time. This experiment demonstrated that in cases when ADAPTS was run, the software did a good job capturing the evolution of storms and reduced the volume scan time by as much as 30 seconds. Here are some of the anonymous comments that we received from the PARISE 2009 participants:
"Theory behind ADAPTS appears on target and it is hands-off, which is good. Timeliness of radar scans is critical, and if we can get quality scans faster, we are all for the work on ADAPTS."
"Favorable. Good to get scans more often and we didn't notice any data missing from the scans."
"Idea makes a lot of sense and I did not see any negative impacts to data retrieval."
"We did not see any blatant issues and think it is useful in this case."
To mitigate some of the limitations of the proof-of-concept algorithm, an advanced version of ADAPTS was developed for PARISE 2010. A second version of ADAPTS: ADAPTS II was developed in 2012. This algorithm incorporated a surveillance processing mode and used adaptive spatial sampling. This paper describes ADAPTS II in great detail. In the spring of 2013, we further improved the ability of ADAPTS to produce faster updates with timely detection of newly formed storms. ADAPTS III introduces the scheduling and processing of a separate detection scan, which can eventually by used for mutifunction applications.
During PARISE 2013, NSSL scientists worked with NWS forecasters to understand the strengths and limitations of weather-radar scan strategies in their warning-decision process.
We recently received National Science Foundation (NSF) funding for our research project titled "Understanding Polarimetric Radar Tornadic Debris Signatures Using Modeling, Simulations, and Field Measurements."
The Spring 2013 software release on the NWRT PAR is now operational. Among other things, this new software release adds and improves adaptive scanning capabilities, a very timely accomplishment as we enter the busiest season for radar data collection.