Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />SECTION I. <br />RESEARCH AIRCRAFT OBSERVATIONAL AJIID MEASURBMEN'l' PRCIGlWI <br /> <br />(a) The Instrumentation Prograal <br /> <br />Intensive efforts were made at the beginning of this prclgram to modify <br />the inertial platform computer to allow it to drive the pen plotter and so <br />provide real time aircraft track, and time strip plots of aiJ:~craft altitude <br />and SF6 concentrations. The system was designed to service t:l1ree ];>eriph- <br />erals, the plotter ,the pressure transducer and the SF 6 instJ:~ument, via a <br />fibre optics link, which is necessary to ensure inertial computer ':immunity <br />from noise. <br /> <br />The interfaces were designed and built. Each one is on a dailSY chain <br />where it is activated when it recognizes its number in a transmitted byte. <br />The pressure and SP6 then immediately transmit their respective re.!dings <br />back to the computer as two consecutive bytes. The plotter lLs ale:rted to <br />its address to receive the data stream for plotting. Data CClnnot be mis- <br />taken as an address because it uses a np in the parity position (j~SCII is <br />a 7-bit code + parity). <br /> <br />The software for this task involved an extremely sophis1:icated rewrite <br />'Of the regular plotter drive routines, so they could be inte]~leaveld with <br />the inertial navigation program so the inertial system could sustain its <br />required repetition rate of 10 times per second. This invo11iTed nUlmerous <br />detailed problems, each of which had to be solved. For example, if the <br />plotter stopped, restart routines had to be written to start the plot again <br />withou~ affecting the inertial platform. The plotter had to also allow <br />manual stops to change paper, roll it up, etc., without 10sil1g data. This <br />software was completed and also included the capability for simple expan- <br />sion to service many instruments on the same fibre optics daisy chain. <br /> <br />In addition, in the early phases of this program the ailC'craft had to <br />be cleared of its military equipment and mountings arranged :Eor our equip- <br />ment. This was also completed satisfactclrily. <br />