NPP Calibration and Validation Rehearsals

1. NPP Calibration and Validation Rehearsals Janna H. Feeley NASA JPSS Ground Project Greenbelt, MDThe Aerospace CorporationEl Segundo, CA Overview The National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) Calibration and Validation (Cal/Val) Rehearsals were held in the summer prior to the NPP launch on October 28, 2011. Incorporating participation by all those involved in the Cal/Val process - the fourteen discipline teams responsible for Calibration and Validation activities, sensor vendor teams, Joint Polar Satellite System (JPSS) Ground and Flight Project personnel, Raytheon Common Ground System (CGS), and Northrop Grumman Aerospace Systems, Algorithm and Data Products support - the Rehearsals provided the Cal/Val program the opportunity to exercise tools, interfaces, and processes an end-to-end prior to the launch of NPP. The Cal/Val Rehearsals exercised key aspects of the Cal/Val Operations Concepts (OPSCONs) in a manner realistic to the post-launch Cal/Val plans. The Cal/Val Rehearsals were divided into two phases to allow for dedicated and in depth focus on specific areas of the Cal/Val OPSCONs. In addition, simultaneous scheduling with the fourth mission-level NPP Compatibility Test (NCT4) allowed for extended interactions with NPP mission operations and flight project personnel. Objectives • The broad objectives of the Cal/Val Rehearsals are as follows, and the figure on the right demonstrates the interfaces tested in support of these objectives. The objectiveswere fine-tuned within each of the discipline teams according to each team’s specific tasks, concerns, and levels of readiness: • Objective #1: Demonstrate communication and product flow (data, results, findings) among Cal/Val team members and with the JPSSProject. • Objective #2: Demonstrate readiness to access necessary data to support Cal/Val analyses. • Objective #3: Demonstrate Cal/Val tool and task readiness for NPP Cal/Val. • Objective #4: Exercise the process for requesting and implementing algorithm changes into the operational software. • Objective #5: Identify areas requiring rework prior to post-launch readiness . Interfaces tested during the NPP Cal/Val Rehearsals. • Objective #1: • Demonstrate Team Communication & Product Flow Objective #2: Demonstrate Access to Necessary Data Objective #3: Exercise Cal/Val Tool and Process Readiness With fourteen, geographically dispersed NPP Cal/Val Teams, establishing regular, centralized means for communication of issues and findings is essential to the success of the Cal/Val Program. The Rehearsals required that each team establish regular team tag-ups and team websites in order to efficiently conduct these communications. These communication processes were rehearsed both within the individual Cal/Val teams, as well as across discipline teams, particularly to demonstrate SDR-EDR interactions. These cross-team interactions are essential to providing downstream product teams with awareness of potential impacts to their product, as well as for providing a means to feedback findings to the upstream product teams. In addition to communication within the product teams, communication amongst JPSS project personnel and the Cal/Val community was emphasized during the Rehearsals. A set of point-of-contacts, still in use post-launch, was established for resolution of reported Cal/Val issues and discrepancies. A primary component of this set of POCs is the JPSS Ground Data Product Engineering (DPE) Algorithm Integration Team (AIT), responsible for one-on-one interaction with Cal/Val team members for support of algorithm change verification and general provision of knowledge about specific algorithms. These interactions were established during the Cal/Val Rehearsals and have become a key component of the Algorithm Change Process. Below is a screen shot of the VIIRS SDR-EDR team weblog, through which findings are to be communicated post-launch. • The Cal/Val teams will access a multitude of data types to support their analyses. In preparation for this, the Rehearsals required that all Cal/Val team members have appropriate accounts set up for access to these data and that realistic data pulls be exercised. The Cal/Val Rehearsals demonstrated successful access of the following types: • NPP Proxy Data • Satellite Test Data • Correlative and ground truth datasets • Datawere pulled from GRAVITE, CLASS, SDS and other sources as defined in the Cal/Val OPSCONswith the frequency and volume required post launch. The figure below shows the cumulative data volume pulled the from GRAVITE system during the ‘GRAVITE Transfer Protocol Stress Test’ of Phase 1 of the Cal/Val Rehearsal. • The NPP Cal/Val program leverages knowledge and experience from Cal/Val participants in heritage meteorological satellite programs. The individuals within these teams are leveraging heritage tools and processes for execution of the NPP Cal/Val. During the Rehearsals, the NPP Cal/Val teams successfully exercised these heritage tools, as well as newly developed Cal/Val tools with the HDF5 NPP data format using proxy data developed on the GRAVITE System, as well as the Platinum 72 (P72) dataset generated for purposes of NPP System Integration and Test activities. A full complement of sensor modes is represented in the dataset using proxy, synthetic, and spacecraft recorded data collected from thermo-vacuum (TVAC) testing. In addition, the dataset includes all the necessary time synchronized Mission Support Data (MSD) such as ancillary and auxiliary data needed to produce xDRs. The output of the P72 test runs is properly formatted NPP data available for use in exercising Cal/Val tools and applications. Sample tool outputs using NPP proxy data are provided below. Global gridded VIIRS EDR of Cloud Top Height for orbit 12 of the P72 dataset pulled from GRAVITE (courtesy of Min Oo and Geoff Cureton, Atmosphere PEATE) Demonstration of the NOAA Center for Satellite Applications and Research (STAR) Integrated Calibration/Validation System using ATMS Proxy Data. Courtesy of Li Bi, NOAA STAR Cumulative data volume pulled by specific users during the ‘GRAVITE Transfer Protocol Stress Test’ of Phase 1 of the Cal/Val Rehearsal. • Objective #4: • Exercise Algorithm Change Process In order to successfully validate the NPP products, Cal/Val teams will be making changes to ground processing software as well as sensor look-up tables on orbit.To support timely and efficient implementation of necessary changes, an Algorithm Change Process has been established by the JPSS program, starting with the identification of a discrepancy and ending with the implementation of a fix into the operational software. The individual steps of this process are handled by different responsible individuals, including the Cal/Val teams, JPSS Ground Data Products and Algorithms (DPA), DPE and Interface Data Processing Segment (IDPS) elements, and Raytheon CGS. Thisintroduces a complex process that requires prelaunch rehearsal in order to be demonstrate post launch readiness. The Rehearsal required that specific Cal/Val teams step through the Algorithm Change Process from end-to-end. In addition it required that each team identify a POC to lead this process for post-launch Cal/Val. During the Rehearsals, the Cal/Val teams identified scenarios for modification of a LUT, processing coefficient, and algorithm and successfully stepped through the process for each of these scenarios. In addition, real fixes to ground and sensor processing coefficients were implemented into ops as part of the NCT4 system level test. Below are the outputs from the VCM tuning exercise demonstrated as part of this process. The images show outputs of the VCM Visualization Tool developed by The Aerospace Corporation for purposes of VCM threshold tuning. • Objective #5: • Identify Path Forward to Launch Participants in the Cal/Val Rehearsals reported issues in the Cal/Val Rehearsals Issues Log on CasaNOSA, the predecessor for the current Cal/Val Issues Log (see right) . These issues were prioritized and worked off by members of the JPSS DPA/DPE prior to launch, establishing a successful process for response to Cal/Val team issues. The DPE AIT roll has remained prominent in the resolution of many of these issues, particularly as a key role in the Algorithm Change Process. Lessons Learned from The NPP Cal/Val were captured in Cal/Val Rehearsal Reports and incorporated into updated Cal/Val OPSCON planning. The Rehearsals ensured significant strides in post-launch planning and readiness, establishing a foundation for the NPP Cal/Val currently in progress. Overview of tuning impacts to the VIIRS Cloud Mask. On the left is a display of the SDRs; in the middle is the untuned VIIRS Cloud mask; on the right are the results after tuning of relevant thresholds. Courtesy of James Drake and Thomas Kopp, The Aerospace Corporation AMS 2012 203408 AMS • 2012