Survey of OSPO Efforts to Improve Operational GOES Imagery S. Hadesty*, K. Ludlum**, N. Sanders*, C. Thomas* * ASRC Federal Contractor – Engineering and Mission Operations Support Service (EMOSS) GOES INR Engineer ** NOAA Federal – National Environmental Satellite Data and Information Service (NESDIS) Office of Satellite and Product Operations (OSPO) Mission Operations Division (MOD) Support Branch  Improved geometric calibration of imagery through recovery of degraded navigation measurements  Increased image data quantity through schedule optimization and reduced payload idle durations  Restored special frames for rapid scans and supported GOES-R testing

As a result of suspect star measurements GOES-15 experienced a 37 km grid shift on September 9, 2013 Investigation showed that the stars were suspect due to degraded star measurements during eclipse, which produced a double peak star compared to the expected single peak. A short term fix was to smooth the star measurements to a single peak. (see double peak star) The long term fix was to modify software to account for the double peak stars during eclipse. GOES 15 Star ID 767 Time 13/265/11:13: Single Peak Star Double Peak Star Improving Geometric Calibration of GOES Navigation Data during Eclipse GOES 15 Star ID 734 Time 13/265/ 09:43:14.541

During eclipse GOES NOP star measurements degrade due to thermal shifts in the secondary telescoping mirror and potato chipping/warping of the scanning mirror. With the software able to process the double peak star measurements GOES attitude knowledge during eclipse has significantly improved. The degradation in the payload that produces the double peak star measurements is expected to increase as the payload ages. Uneven Heating of the Secondary Telescoping Mirror during Eclipse Detectors Scan Mirror Primary Telescoping Mirror Secondary Telescoping Mirror Improving Geometric Calibration of GOES Navigation Data during Eclipse

The GOES INR team supported single star tracker operations during GOES-15 star tracker 1 anomaly. During operations with one star tracker INR residuals ping ponged out of spec and SSAAs (short span attitude adjusts) were used to keep the residuals in spec. Utilizing the SSAAs allowed GOES- 15 to remain operational as GOES West with one star tracker. 3 km = 86 micro-radians. Improving Geometric Quality of GOES Navigation Data During GOES 15 Star Tracker Anomaly With SSAA Without SSAA Outside spec. SSAA enabled

Optimized N/S Maneuver and Yaw Flip Recovery Schedules The Optimized Recovery Schedules currently utilizes the Routine Schedule with double star looks instead of the Short Full Disk Schedule that was used prior to Jan This change was made possible from attitude solution trending and improved N/S maneuver performance prediction. Attitude solution trending from serval years has shown that reusing the attitude solution from a similar day of year (DOY) from past years significantly decreases the recovery time required post yaw flip. Navigation trending data from N/S maneuvers has increased performance prediction, which has allowed for more predictable E/W performance from the N/S maneuvers. Imager Recover Frames Now Imager Recover Frames Before OLD SCHNEW SCH% Recovered Imager (mins/hr) Sounder (mins/hr)

On August 7, 2014 a test for a special Hawaii frame was conducted to view two hurricanes. This was a legacy capability from GOES IM and used for the first time on GOES NOP. As a result of recent testing, at NESDIS, the NWS and CIMSS, GOES-15 (West) is once again able to call Rapid Scan Operations (RSO) over Hawaii. RSO was then called for almost 6 days to monitor Tropical Cyclone Ana. Currently testing two additional legacy frames for the Alaska region and a future frame for America Samoa. Restored alternate rapid scan capability for GOES NOP

GOES-13 Optimized Schedule Increased the coverage from the GOES-13 imager (May 2014). The size and/or start time of certain sectors was changed. The routine and Rapid Scan schedules were tested and implemented. More information is available at Comparison of the size of the Continental U.S. sector (before, left) and the extended coverage (after, right). Optimized CONUS sector (after) CONUS sector (before) More data

Supported GOES-14 Super Rapid Scan Operations to Prepare for GOES-R (SRSOR) GOES-14 SRSOR was requested to simulate GOES-R ABI data. During SRSOR testing small sections of earth are viewed. This leads to few if any landmarks during these operations. GOES NOP normally utilizes landmarks, ranges and star measurements in solving for a full orbit and attitude solution. It was determined from INR analysis that GOES-14 could solve for an attitude only solution for up to two weeks and remain near INR spec. Currently SRSOR plans for 2015 include May 18-June 12, and August 10-22: 8 GOES-14 visible image showing rapid convective development