Annexure -1
1. Title of the invention
An improved process in the field of Flight Test Instrumentation (FTI) for Post-processed GPS Data acquisition.
2. Field of invention
This invention relates to improved Flight Test Instrumentation process for acquisition of Post-processed GPS data and better synchronization of the same with other Flight Data for efficient flight monitoring and post-flight analysis.
3. Use of invention
This invention can be used to synchronize the GPS data with other flight test data for developmental aircraft for real time monitoring and post flight data analysis. The synchronized flight test instrumentation will enable effective data analysis for developmental flight trials including formation/networked flying scenario as well as single aircraft flight test scenario. This process is useful for development program of fixed wing aircraft, rotary wing aircraft, unmanned aerial vehicles etc. This process will also be useful for any other data acquisition and processing system which can be synchronized with the help of GPS parameters.
4. Earlier Process
Flight Test Instrumentation is instrumentation of a developmental aircraft to acquire various system parameters to validate the aircraft design. The acquisition of the parameters is done through various FTI sensors (Temperature, Pressure, Thermocouples, Strain Gauges, Air Data Transducers, Accelerometer, Gyro's etc.), FTI Analog and Discrete signals, Aircraft Bus Data (MILBUS, RS422, ARINC-429 etc.) etc. through a Data Acquisition Unit(DAU) which has different modules for different kinds of data. The same is also recorded onto a Solid State Recorder (SSR) for post flight analysis. One of the important data for any flight test program is GPS data. The GPS time is very useful in proper synchronization of various data. The parameters such as position co-ordinates(Iatitude and longitude), altitude, track angle, ground speed etc. can be used for validation of aircraft navigation equipments. The same data can be used for validating the performance parameters of an aircraft. For example: Altitude parameter can be

Annexure -1
used to ascertain highly accurate measurement of climb performance, Position co-ordinates can be used for Range determination etc. The process which was used originally for GPS data acquisition consisted of a GPS base station at an exactly known location and an onboard GPS receiver on the aircraft. The GPS receiver's acquire and store the data during the flight. After this data used to be extracted and post processed using post-processing software supplied with the GPS Receiver. The GPS data as shown in the figure 1 was completely independent of all other FTI instrumentation.

Annexure -1 5. Draw backs of earlier process
• As the GPS acquisition was independent of FTI, the FTI data acquisition unit was incapable to ascertain the GPS receiver validity.
• The data extraction from the GPS Receiver was an un-necessary additional task for FTI Engineer.
• The data extraction could be carried out only using a laptop with a special RS232 port which was an additional resource to be maintained by FTI.
• Lack of data sync between GPS and rest of the FTI data for real time flight monitoring.
• Lack of data sync between GPS and rest of the FTI data for post flight analysis.
• The merger of GPS data with FTI data was a tedious job due to lack of any common parameter between the two.
6. Comparison between earlier process and present invention
The new process integrates the GPS Data acquisition with the main FTI which leads to better synchronization of data and also enables the health monitoring of GPS data along with all other FTI equipment. GPS data is readily available along with other FTI data and so the first step in processing of GPS data becomes common with all other FTI data. It saves resources and time as once the design is implemented on the aircraft the whole process gets integrated into the main FTI task.
7. Aim of the invention
The aim of the invention was to integrate GPS Data acquisition with rest of the FTI data acquisition. It was envisioned to eliminate un-necessary FTI tasks and streamline the process of GPS data acquisition. The aim was also to increase the reliability of data availability through the health monitoring of GPS receiver in real time. It is said that time is most important resource and it was felt that the automation in the process of GPS data acquisition will free up a FTI Engineers time for more fruitful tasks.
8. Summary of the present invention
The drawbacks of the earlier process was obvious to the FTI team and it was decided to find a solution for GPS data acquisition as it was felt that integration of the same with total FTI would lead to lots of benefits for the flight testing

Annexure -1
program. With this in mind the GPS data output from the GPS receiver was studied closely to study the feasibility of acquiring the same into the DAU for real time operation. Simultaneously the feasibility of recording the same in the SSR for post flight analysis was also studied. The existing set-up had modules in DAU as well as in SSR which could acquire the data through proper hardware modification. The modification consisted of fabrication of new cables to wire the units to the GPS Receiver data output port. The same was fabricated and the designed scheme was implemented. The data was successfully acquired and recorded. The next step was to post process the recorded data. It was found that the recorded data required further processing to get it into the format required by the post-processing software. Conversion software was written to make the SSR file suitable for the post processing software. The converted file was successfully processed and.found to be exactly same as the earlier process.

Annexure -1
10. Statement of invention
The new process integrates the GPS Data acquisition with the main FTI which leads to better synchronization of data and also enables the health monitoring of GPS data along with all other FTI equipment. The GPS data is readily available along with other FTI data. It saves resources and time as once the design is implemented on the aircraft the whole process gets integrated into the main FTI task. The new process can be used in development testing of fixed wing aircraft, rotary wing aircraft, unmanned aerial vehicles etc.
11. Detailed description of invention
Step 1: Study of the GPS data output format from the GPS receiver.
Step 2: Fabrication of cables for connecting GPS Receiver to the Solid State Recorder (SSR) and Data Acquisition Unit (DAU).
Step 3: Carrying out the necessary looming and cable laying in aircraft for doing the connection.
Step 4: Programming the SSR and DAU to acquire the GPS data.
Step 5: Development of software to convert the recorded data into suitable format.
Step6: Real time monitoring of GPS data to ensure serviceability.
Step 7: Extract Data from SSR recording along with other FTI data.
Step 7: Convert the data to required format to suit the analysis software.
Step 8: Post processing of GPS data to get the accurate GPS location of aircraft.
Repeat Step 5 to Step 8 for every flight.

Claims
We Claim that,
1. Time synchronization of FTI recorded data with post - processed GPS data.
2. The new process results in data sync between GPS and rest of FTI Data during real time flight monitoring.
3. The new process results in data sync between GPS and rest of FTI Data for post-flight analysis
4. Can be used to verify the proper functioning of onboard GPS.
5. The new process results in decrease in turnaround time of the aircraft after the flight.