# Presentation: 116769

## Advanced Attitude Determination, 

**Benefits**
- Improved ground attitude estimation and sensor calibration accuracy.
- Automation of ground attitude estimation and sensor calibration.
- Improved knowledge of sensor characteristics enhancing current and future missions.
- Quicker detection of onboard attitude estimation and sensor calibration errors.
- Onboard Sensor Calibration Algorithms.

**Objectives**
- Investigate and implement algorithms which improve onboard and ground attitude determination accuracy and performance.
- Investigate and implement algorithms which improve onboard and ground sensor calibration accuracy and  performance.
- Investigate sensor and actuator performance and apply toward future missions.
- Improve flight dynamics attitude models.
- Improve response time for spacecraft recovery.

**Features**
*Automated Gyro Calibration*
*Robust Star ID Algorithm*
*Enhanced Spinning Spacecraft Attitude Estimation*
*Enhanced Sun Sensor FOV Calibration*
*Attitude Determination Accuracy From Mission Experience*

**Advanced Attitude Determination, **
**Calibration and Modeling**

**Summary**
- Under this task, investigation is performed for improvements in the methods by which spacecraft attitude (ground and onboard) sensor/actuator measurements and reference data are efficiently processed to determine attitudes, and provides analysis of sensor performance, anomalies, and modeling for a wide variety of current and future missions.  With a view to improve mission support, new algorithms are developed for attitude determination, attitude simulations, attitude control, and efficient calibration of attitude actuators/sensors. Prototypes are developed using in-flight as well as simulated data and the resulting concepts are migrated to operational ground systems where possible.  The two operational systems are the Multimission Three-Axis Stabilized Spacecraft (MTASS) system and the Multimission Spin Axis Stabilized Spacecraft (MSASS) system.  Both systems have supported more than 18 operational missions.  The systems themselves were developed in MATLAB which by default makes them multi-platform compatible and relatively easy for engineers who use MATLAB for analysis to enhance.  All analysis performed on this task is performed in MATLAB which allows for easy integration into MTASS and MSASS.  In addition to these specific work items, consultation is provided on general issues and analysis of methods for attitude determination and calibration as well as sensor modeling and performance.  The results of any analyses deemed by the technical representative to be of broad enough interest to the aerospace community are disseminated via technical memoranda and professional papers.

***Note:  When available,  this effort is complemented by funds from other sources.***

**At A Glance**
-  The Advanced Attitude Determination, Calibration and Modeling task develops the state of the art algorithms and systems that will support the high accuracy future missions while providing more efficient systems for current missions.

**NASA GSFC Mission Services Evolution Center, Code 581**
**Greenbelt, Maryland  20771**
- _[http://](http://gmsec.gsfc.nasa.gov/)__[gmsec](http://gmsec.gsfc.nasa.gov/)__[.](http://gmsec.gsfc.nasa.gov/)__[gsfc](http://gmsec.gsfc.nasa.gov/)__[.](http://gmsec.gsfc.nasa.gov/)__[nasa](http://gmsec.gsfc.nasa.gov/)__[.](http://gmsec.gsfc.nasa.gov/)__[gov](http://gmsec.gsfc.nasa.gov/)_
**email:  **gmsec@nasa.gov

##  GMSEC Advanced Attitude Determination, Calibration and Modeling

-  GMSEC Advanced Attitude Determination, Calibration and Modeling

**Features**
- Several of the most recent prototypes are demonstrated below.  The systems include an enhanced attitude estimation algorithm for a spin stabilized spacecraft, automated gyro calibration, and star identification using a pattern match.

**Applications**
- The systems being developed under this effort are applicable to a wide range of GSFC missions including ST-5, SDO, GPM, MMS among others.   The operational attitude estimation and sensor calibration systems have been used by over 18 different missions.    Two representative displays from this system are shown below.

- Enhanced Spin Stabilized Spacecraft Attitude Estimation

- Automated Gyro Calibration

- Star Identification