Session 7 At SOAR By Avembsys

            The session began on a usual note with a quick brush up on concepts of 'C'. For the day discussions were on structures, its types, different ways of passing structures to functions..

            Our SME took over the session and introduced us to the various software models like,
>Waterfall model
>Spiral model
>V model
To jot them in brief would be like,
Waterfall model:
In this model the approach is irreversible. A particular phase begins only after the completion of the previous phase without having a viability of revisiting the previous phase. The mistakes made in one would lead to the mistakes of the following which ends up disastrous. Hence alertness and atmost care has to be taken if this model is used and therefore not employed for critical systems. The advantage is its certainity. The disadvantages are that there is no room for RFCs and also its unidirectional property. Therefore to overcome these shortcomings the next model was developed.
Spiral model:
In this model there are four quadrants each denoting a phase. Here a prototype of the complete system is made first and approval of the client is obtained. The increase in the spiral radius conveys that the system is becoming complex and reaches completion. This model is used more for a product than a software or for a longterm project.
V model:
In the V model the requirements are tested at the phase level by preparing test cases for each phase that can be tested later when the system is complete.;that is the requirements are tested at each phase. The advantage is that we are not taking anything for a chance and all the requirements of a client can be accomodated.

             We were then shown a software requirement specification document(SRSD) which gave an overview of  the contents present in it and came across many terminologies like the usecases which later form into test cases.They actually tell what an actor does on a system.
We then moved on to the domain concepts, under which terminologies related to airports and airspace were discussed like the runway which is a path where the aircraft takes off or lands. A thought provoking part was on how the runways are numbered. A runway number is one tenth of the magnetic heading. Then we moved on to learn about taxiway which are links connecting the runways and the airport parking areas, windsocks, runway types, various sign boards present in an airport out of which the 6 basic ones are mandatory, location, direction, destination, information and runway distance remaining. We also learnt about the lighting systems that are adopted by the airports for proper visibility of the runways like the approach light system, runway edge lights, in runway lighting, taxiway lighting, visual approach slope indicator(VASI) and the precision approach slope indiactors(PAPI).

            Then we moved on to the concept of controlled airspace which is divided into 5 classes namely: Class A, B, C, D and E respectively and the uncontrolled one is class G.
Special airspaces are namely: prohibited areas, restricted areas, warning areas, millitary operations areas, alert areas and controlled firing areas. Then a little about ATCs on how they used markers across a map to estimate the position of aircrafts. Also about methods adopted for landing over cloud ceiling and bad weather. The session was officially ended by an introduction to the ILS whose skeleton we knew already from our previous sessions.

            Personally it was a fun filled session which Im sure even my friends would agree too which is actually  helping us learn the concepts in a better way. Owing it all to our SME.....Awaiting for the next session....

Session 6 At SOAR By Avembsys

            The session started off with small tit bits by one of our mates on the presence of bugs in a program. Later our SME took over the session to explain the concept of SDLC (Software Development Life Cycle). Coming from a hardware background it was a newfangled concept for me, which I enjoyed thoroughly understanding it.

             Software Development Life cycle is a process to develop a system which includes four phases namely:
Analysis        -10%
Design          -20%
Development-20%
Testing         -50%
The percentages show the amount of thought and work invovled in each phase, but also they are transient and depends upon the system in consideration.
Software Development Life Cycle results in a high quality system that meets the customer expectations, reaches completion within time and efficiently designed for the current technology.
SDLC is a type of methodology used to describe the process for building information systems, intended to develop information systems in a very deliberate, structured and methodological way, reiterating each stage of the life cycle.

The phases can be gathered up a little more in detail as follows:
Analysis:
In this phase the thought process involves finding the problem through questionaire, analysing the feasibility of process and also about the requirements from the system. Feasibility has two categories, one being the technical under which the limitations of the technology is taken into account and the other one is commercial feasibility which has two factors..(1) technology should'nt be developed so costly which is commercially not viable.(2)technology should'nt be developed whose cheaper alternative is available.
Requirement includes collection of problems and subproblems.
Outcome of this phase is Software Requirement specification Delivered (SRSD) which is sent to the client for approval.

Design:
It involves Software Development Model. It starts with the top level design under which we have the HLD and LLD.
High Level Design(HLD):There are 3 steps under this..
1>Algorithm: It is a step by step approach of doin anything.
2>Flow Charts: Is basically a diagrammatic representation that gives a step by step solution to a given problem.Process operations are represented in boxes and the arrows connecting them represent flow of control.
3>Block Diagram: Shows the interconnection between the components of a system.
Output of HLD is HDD(High Level Design Document). From HDD we get a fair idea about the system.
Low Level Design(LLD): The 3 steps are:
1>Data Structure:Its basically the organisation of data and its storage allocations in a computer.
2>Logic: In simple words its the art of thinking and reasoning in accordance with limitations and capabilities if human understanding.
3>Functions:Its a block of code that performs a calculation and returns a value.
Output of LLD is LDD(Low Level Design Document) or a detailed design document.

Development:
Coding is the translation of data from the user's language to the system's language like C, C++, java etc....and the necessary standards are followed.

Testing:
Its the process used to measure the quality of the developed system. Its a phase that holds the maximum importance.

          The session thus ended which was a newfound and interesting one..

Session 5 At SOAR By Avembsys

              The session started off with one of our mates brushing up on the basics of branching and looping concepts of 'C'. After this our SME gave an insight into what is an IMEI. We then saw a few slides on our very new light combat aircraft or otherwise called as Tejas: India's first intelligent fighter plane. We then moved on to know what is an Avionics system, otherwise called as aviation electronics which is defined as all electronics and electro mechanical systems and subsytems installed in an aircraft or attached to it. It has emerged as the central integrated technology and must be integrated in the conceptual design phase in the design of the aircraft. The different principle drivers are safety, mission of the aircraft, life cycle cost/cost of ownership and certification which is a major factor in avionics design. The various certifications are FAA (Federal Aviation Administration) in America, DGCA (Director General Of Civil Aviation) in India, CEMILAC (Certificate For Fighter Plane Centre For Military Airworthiness Certificate), ADA (Aeronautical Develop Agency). We then learnt about the various avionics on a multipurpose aircraft namely the IFF which identifies whether the aircraft from the enemy territory is a civil one oa a fighter plane and shoots down if its not a civil aircraft, MLS, weather radar, marker beacon, DME, VHF 2/Military UHF, ATC Transponders, ICAS, Radio Altimeter, Line TV, VOR/LOC 1 &2, FM Broadcast, ADF, UHF Satcom etc...
               The next concept of the day was navigation under which there are Dead Recokoning Navigation System, Mapping Navigation System, Flight Control, Engine Control(FADEC), Flight Mnagement(heart and brain of an aircraft), Subsystem Monitoring And Control, Collision Avoidance, Weather Detection. The various datas involved in avionics are fresh and valid, which is the only one that has to be considered and the other ones are fresh and invalid, stale but valid and stale but invalid. We then had an insight into the professional coding standards and it was amazing to know the various facts about it like the number of variables it holds and also the significance of each. We then moved on to the concept of ELT(Emergency Location Transmitter which is a subsystem and is triggered automatically on high-g impact. It emitts distinctive tones on 121.5, 243 and 406MHz, where 121.5MHz is an emergency frequency which every pilot has to tune to.
               The regulatory and advisory agencies are:
1.ICAQ-International Civil Aviation Organisation
2.FCC-Federal Communication Commission
3.RTCA-Requirements And Technical Concepts In Aviation
4.ARINC-Aeronautical Radio Incorpated owned by USA and defines standards for communication
   protocols.
5.SAE-Society For Automotive Engineers
6.IEEE-Institution On Electrical And Electronics Engineers
7.JAA-European Joint Aviation Authorities
8.EUROCAE-European Organisation For Civil Aviation Equipment
               We then discussed an avionics system in detail which is the EGPWS(Enhanced Ground Proximity Warning System) which provides caution and warning to the pilots about the terrain around the aircraft. Basic functions of EGPWS are categorised into seven modes namely:
Mode 1:Excessive Descent Rate
Mode 2:Excessive closure to terrain
Mode 3:Altitude loss after take-off
Mode 4:Unsafe terrain clearance
Mode 5:Excessive glide slope deviation
Mode 6:Advisory callout/Bank angle
Mode 7:Wind shear alerting
              The last concept for the day was the TCAS(Traffic Collission And Avoidance System) which consists of two types of alerts such as:
Traffic Advisories (TA's): to assist the pilot in visual search of intruders(TCAS 1).
Resolution Advisories:To resolve potential mid-air collissions(TCAS 2).
This marked the end of the session.

Session 4 At SOAR By Avembsys

                   The session started off on a lighter note, perhaps an important one that is the evolution and classification of Aircrafts. It was interesting to know how man started thinking about the various ways to fly which has eventually led to the sophisticated aircrafts we have today because of their amazing foresight. To name a few like the ornithopter by Leanardo Da Vinci in 1500, Lighter than Aircraft by Francisco De Lan-Terzi in 1670, Airplane which was George Cayley's model in 1804, Glider by Otto Lilienthal in 1896 and here comes the milestone that is the Flyer which was the first powered, sustained and controlled flight by the great brothers Orville and Wilber Wright on december 17, 1903.

                   We then moved on to study the classification of aircrafts based on various parameters like,
1.Based on the Space they operate
   (Troposphere, Stratosphere, Mesosphere, Ionosphere)
2.Based on Propulsion
  a>Propelled     b>Unpropelled
3.Based on Crew
  a>Manned       b>Unmanned
4.Based on Wings
  a>Fixed wings  b>Rotary wings
5.Based on Type of wings
  a>Monoplane   b>Biplane     c>Triplane
6.Based on Landing mode
  a>Sea              b>Land         c>Amphibian
7.Based on Engines
  a>Propeller          b>Turbofan   c>Turboprop
8.Based on Number of engines
   a>Single          b>Twin         c>Multiple
9.Based on Function
   a>Fighter         b>Bomber    c>Transport

                 We then discussed about a few special types of aircrafts like the Reconnaissance which has a very high speed and difficullt to chase and shoot;example is a Microplane and the AWACS(Airborne Warning and Control System);example is Aerial Refuelling which ejects tentacles for the purpose. The other special types are the Vertical Take Off  which has a tilt rotor and it takes off and lands like a helicopter and the Stealth which is for conventional and nuclear weapons. The  best part of stealth is that it cannot be detected by any radar in the world and is naturally very expensive making it less affordable by all countries. Light was thrown on the very mysterious Bermuda Triangle which is a nightmare for the aircrafts and ships because of its rough weather and electromagnetic radiations.

                We were then exposed to a case study on an aircrash of Avianca flight 052 which ocurred on 25th January 1990. The transparent reasons for the crash were,the bad weather of JFK airport, miscommunication between the pilots and the ATC, the lack of alertness among the ATCs when it came to transfer of vital details and information among themselves, the poor english of the main pilot due to which he had to depend on his co-pilot for handling the critical situations and the usage of the word 'priority' instead of 'emergency' by the first officer which did'nt make the ATC serious enough. During such a situation a pilot can also use the word 'MAYDAY' thrice which means accute emergency state. The pilots had to go for a 'holding pattern' which eventually led to flame out of the engines and the plane crashed killing many lives. I was in tears looking at it but realised that rather than crying, its time for us to work on improving the systems to avoid any such errors to save the precious lives.
                
                Another interesting concept of the day was the ILS(Instrument Landing System). The aircraft has to allign itself to the centre of the runway at around 10km which is the lateral guidance and the vertical guidance guides the aircraft vertically at the required height. ILS antennas are placed at the end of the runways. These antennas emitts two waves of radio frequencies, 90Hz and roughly 121Hz. The aircraft receiver reads the two waves, analyses the dominance and alligns itself accordingly. Thus the session ended with a note by our SME to think on systems and scenarios for Airtraffic Landing Schedule. Looking forward to the 5th session..... 

Session 3 At Soar By Avembsys

            After a long wait filled with eagerness the session began. It started with a quick revision of 'C',by one of our friends explaining the basic concepts which proved quite helpful specially for us EC and EEE students to recall all that we had learnt on it.

           Then the actual session began with discussion on Electronic Warfare which refers to any action involving the use of electromagnetic spectrum or directed energy to control thr spectrum attack on enemy or impide enemy assaults via  the spectrum. We then moved onto the concept of Electro Magnetic Pulse(EMP), where a pulse of high density electromagnetic waves are sent to the enemy devices to destroy them. The day then progressed towards more interesting concepts like the Aerodynamic Basics to mention first, under which we discussed the fundamental concepts of physics like mass and weight, momentum, moment, couple, density, temperature, viscosity and pressure to name a few. Then we moved onto few terminologies like the static pressure which is a measure of purely random motion of molecules in the gas and total/stagnation pressure which means if the fluid element is slowed to zero velocity at a point where the local pressure is static, then the pressure at that point is called as total pressure. To note a point here is that flow reduces static pressure. We then moved on to the concept of pitot static probe and how it is used to obtain the airspeed that is in turn the aircraft's speed using static and total pressure. Its basically a critical instrument used in flight which measures the pressure difference and thereby measuring the speed. We also discussed on the altitude of the flight from various layers, the standard sea level conditions, the basic gas laws,aerodyanamic centre,centre of pressure and the mach number. The slides of the wing structure helped us understand how its shape affects the movement of flight on air. The slide on the aircraft view showed the various parts of an aircraft and helped us to know how each part had their own magnificant role in the control of the flight. We also learnt about forces acting on an aircraft, weight of an aircraft and  various parameters of the wings. The concept of cloud burst which was explained in detail helped us know how it can hamper the flight take-offs and landings. The concept of VTOL(Vertical Take-Off and Landing) was very intriguing which made us think how powerful the engine could be when its producing a thrust same as that of the weight.

        Post lunch break  the crash video shown of an Air France flight  that happened in 1988 was a quite a touchy one which makes us feel the need to be extra careful while dealing with many lives. Further, discussions were based on projects and also the mini project that was assigned to us which is dealing with wireless transmissions between two 8051 modules, which also incorporates a sensor. I am glad that all of us are considering this challenge seriously to make it a success.

Session 2 At SOAR By Avembsys

The session started off getting to know about the 3 basic aspects of human personality which was to 'think','speak' and 'perform'.The 80:20 rule of industries too were mentioned which says-" 80% of problems can be solved using 20% of knowledge and remaining 20% problem has to be solved by using 80% of knowledge".The series of videos which we were then exposed to, threw light on expanding our mental ability towards the industry.One of them being very impressive although it was a movie scene which highlighted on the various embedded systems in a fighter plane.The concept of missiles,the two types heat sensing and laser guided and the various measures taken to counter them like the ECM(electronic counter measures) and also about the cruise and ICBM(Inter Continental Ballistic Missiles) were very intriguing.Light was thrown on the cold war too that existed between USSR and US regarding the satellite Sputnik.We then got to know about the two basic kinds of computer systems which are the stand alone sysytems and the embedded systems,where a stand alone system is one which can  be used for different puposes unlike an embedded system.Not to forget about the Real Time Systems,its types hard and soft real time systems,spy satellites adopted by different countries etc..
                  The second half of the session was very touching..atleast for me..being exposed to the videos of the worst mid-air crashes killing so many lives in split second.One of them being the charkhi dadri mid air collision killing 349 on board although both the flights had the TCAS(Traffic Collision Avoidance System)system.The fascinating part was the emergency approaches taken by the pilots during take-off and landing like the TOGA(Take-off And Go Around) and the crab approach adopted during crosswinds which was a visual treat.With all this we are aware that there is no room for even a minute error in this industry,which can be summarised in a nutshell as 'ALMOST RIGHT IS 100% WRONG'. Awaiting anxiously to visit Avembsys on monday and looking forward towards the third session.............

Session 1 At SOAR By Avembsys

The start of the session was great, with it being the way as expected....looking forward for the amazing opportunities thats awaiting us...