SPECIFICATION OF THE INVENTION

1. Title of the invention

A novel system and computing method for manual tracking of flying aircraft by controlling the telemetry base station antenna with respect to azimuth and elevation of aircraft, in case of failure of auto scanning mode.

2. Field of Invention

The present invention relates to manual tracking of aircraft by controlling the telemetry base station antenna, during flight time in case failure of auto scanning mode of telemetry base station antenna. In particular, it relates to a methodology of tracking the aircraft when the RF link breaks between the telemetry base station and flying aircraft by computing and predicting the required antenna azimuth and elevation angle to establish the RF link.

3. Prior art and draw backs of prior art

Aircraft are equipped with many LRUs i. e mission critical and safety critical LRU/equipment. In transport aircraft safety is priority. Telemetry base station crew needs to communicate with aircraft crew during entire sortie and provide best solution based on getting online data from aircraft in entire flight profile. In fighter aircraft mission is priority. Telemetry base station pilot crew need to communicate with aircraft pilot during entire mission and provide best decision according war scenario based on online data getting from aircraft. Generally communication between aircraft and base station happened through RF link when aircraft will be in FOV of base station antenna. Auto scanning feature of base station provide facility to track aircraft and try to lock aircraft is in FOV of base station antenna automatically. If aircraft comes out from FOV of base station antenna then RF link will break and base station will not get any data from aircraft. At the time of aircraft development phase, telemetry pilots needs to communicate with the aircraft pilot and provide flight critical decision for aircraft pilot based on data i. e engine parameters, ADC parameters etc. Prior to this invention, Tracking of aircraft during flight depended only on auto scanning of base station antenna. If auto scanning failed in some scenario then RF link will break and base station will not get any real time data from aircraft and base station pilots cannot give any flight & mission critical decision to aircraft pilot.

4. Aim of Invention

The main objective of this invention is to provide a novel method to track aircraft manually by controlling base station telemetry antenna efficiently to avoid complete RF link loss between aircraft and telemetry base station in absence of auto scan mode of telemetry base station antenna.

5. Summary of the Invention

This invention presents a module employing a novel method to track aircraft manually by controlling base station telemetry antenna efficiently to avoid complete RF link loss between aircraft and telemetry base station.

The module consists of Input data module [100], Processing & decision making module [101] and Display module [102]. Input data module consists of Telemetry ground station reception units, it will give online aircraft parameters from INGPS or DGPS installed on the aircraft. This module will get continuous aircraft data, If RF link is stabilized between aircraft & telemetry base station. Processing & Decision making module is heart of the system, it consist of data processing sub module [103], stored aircraft database sub module [104], base station information sub module [105] and computing s ub module [106]. This module receives aircraft parameters (raw value) from input data module and converts to engineering value. Stored aircraft database consist of latest 1 minute online aircraft parameters. Base station information having fixed telemetry base station data i.e base station position (Lat, Long & altitude), base station antenna limitation i.e range, azimuth & elevation movement etc. If RF communication broken between aircraft and telemetry base station, computing module will take data (aircraft parameters i.e lat, long, altitude, speed, pitch, heading etc) from stored aircraft data base and compute aircraft position by approximation method. It computes required azimuth and elevation angle based on stored aircraft data base, base station information and data processing module. Display module provides real time as well as expected data on manual tracking GUI. It also provides real time aircraft movement on manual tracking GUI.

6. Brief Description of the Drawings

Figure 1 is Block diagram of manual tacking module for base station antenna.

Figure 2 is Manual Tracking Display GUI

Figure 3 is Flow Chart for Computing Elevation and Azimuth angle.

7. Detailed Description of the Invention

This invention presents a module and method employing a novel method to track aircraft of base station antenna efficiently by manual tracking. This module consists of input data module, processing & decision making module and display module.

• 1st Step: Ensure that input data module is working correctly by checking real time data displayed on real time monitoring GUI. Input data module having telemetry ground station reception units, it will receive online aircraft parameters from INGPS or DGPS unit installed on the aircraft. Selecting of aircraft unit is depends on accuracy of the unit. If RF link is stabilized between aircraft & telemetry base station, this module will get continuous aircraft data and displayed on real time monitoring GUI of display module.

• 2nd Step: If RF link is stabilized then data processing module receives aircraft parameters (raw value) from input data module and converts engineering value. Stored aircraft database module stored latest 1 minute online aircraft parameters and updates continuously. No. of samples available in stored aircraft database is depending upon bit rate used in telemetry station for example bit rate is 50 hz then no. of samples will be 3000. So 3000 samples will be always available in the stored aircraft database. Base station information module having fixed telemetry base station data i.e base station position (Lat, Long & altitude), base station antenna limitation i.e range, azimuth & elevation etc and map information. Computing module computes real time range, azimuth and elevation angle based on real time data given by data processing module and base station information module. Simultaneously, computing module computes expected range, azimuth and elevation angle based on stored aircraft data provided by the stored aircraft data base and base station information module. Finally display module display all computed real time as well as expected data on manual tracking GUI.

• 3rd Step: If RF link failed then data processing module will not get any aircraft parameters (raw value) from input data module. Computing module computes expected range, azimuth and elevation angle based on stored aircraft data given by stored aircraft data base and base station information module. Display module display all computed expected data i.e range, azimuth & elevation angle etc on manual tracking GUI. Move base station antenna based on expected elevation and azimuth angle through manual control present in telemetry base station and try to stabilize RF link. RF link will stabilize if not then following change is required;

■ Check Base station information

■ Check data processing computation

■ Increase the time limit of stored aircraft data base.

■ Check of approximation method used in computing module.

• Computation of Elevation angle, azimuth angle and slant range is given below;
Processing & Decision Making Module Computation;

Conversion degree to radian;

(Lat)BS= Iat1 =Degree+(Minute/60)+(Second/3600) (Long)BS= long1= Degree+(Minute/60)+(Second/3600) (Lat)A/c= lat2=Degree+(Minute/60)+(Second/3600) (Long)A/c= long2= Degree+(Minute/60)+(Second/3600) (Note: BS= Base Station & A/c= Aircraft)

Conversion degree to in radian;

Iat1=lat1*0.01745329 Iong1=long1*0.01745329 Iat2=lat2*0.01745329 Iong2=long2*0.01745329

Computation for Elevation and Azimuth Angle;

del= (long2-long1) x=cos(lat1)*sin(lat2)-sin(lat1)*cos(lat2)*cos(del) y= cos(lat2)*sin(del) z= sin(lat1 )*sin(lat2)+cos(lat1 )*cos(lat2)*cos(del) Ground rang= GR=6371*3280.83*atan2((sqrt(xA2 + yA2)),z)(in ts) Bearing= b=Azimuth= atan2(y,x) (in radian) Azimuth= atan2(y,x)*180/pi (in degree) X= GR *s\n(Azimuth *0.01745329) Y= GR *cos(Azimuth *0.01745329) Alt1 = (Altitude)BS Alt2= (Altitude)^
Z= Alt2 -Alt1 (in fts) Slant Rang= sqrt (PC*X)+(Y*Y)+(Z*Z)) (in fts) Elevation= asin(Slant Rang ,Z) (in radian) Elevation= asin(Slant Rang ,Z)*57.3 (in degree)

CLAIMS We claim

1. A novel method to track aircraft manually by controlling base station telemetry antenna in absence of auto scan mode of telemetry base station antenna consisting of Processing & decision making module [101] and Display module [102].

2. Processing & decision making module [101], claimed in claim 1) consists of data processing module [103] which receives aircraft parameters from input data module and converts to engineering value and provide to decision making module for computation.

3 Processing & decision making module [101], claimed in claim 1) consists of computing module [106] which computes required antenna azimuth and elevation angle based on data stored in aircraft data base sub module, base station information sub module and data processing sub module.

4. Display module [102], claimed in claim 1) displays all computed expected parameters i.e range, azimuth & elevation angle on GUI to control the movement of telemetry base station antenna . It also provides real time aircraft position on display.