The_Bullet_Chef Posted March 28, 2019 Posted March 28, 2019 (edited) SOLVED Each scale range between each of the scale ‘dashes’ on the left side of the DDD is always a ‘600 knot range’ regardless of ASPECT switch position. The total ‘closure differential spread’ will always be 2400 knots. The 0 position actually moves up or down to the next dash depending on ASPECT switch position. For example, with the ASPECT switch in TAIL, the ‘0 knots’ closure point moves up one to the dash above the middle dash, meaning that the 3 gaps (or closure ranges) below this new ‘0 point’ are (0 to -600 knots) (-600 to -1200 knots) & (-1200 to -1800 knots) and the single gap (or closure rate) above this new ‘0 point’ is (0 to +600 knots) Hope this helps others out there. Hello Developers, May I please get some clear clarification relating to the 'ASPECT' Switch position and its relationship to the DDD Target? The quick scenario I set up was as follows; Head to Head with the 'enemy' aircraft, with the 'enemy' aircraft speed at 250 knots. Below I attached 3 quick successive pictures of the DDD in the scenario described above, with the ASPECT Switch in 3 different positions (1) BEAM (2) TAIL (3) NOSE. I am interested in the RAW DDD Data in the PD-Search Mode. The manual states the following; "The display shows closure rate vs the ground (as if own aircraft was stationary) as opposed to relative closure rate." "The operating range of the doppler filters can also be configured by the ASPECT switch on the same panel, NOSE sets 600 knots opening to 1 800 knots closing, BEAM sets 1200 knots closing to 1200 knots opening and TAIL sets 1 800 knots opening to 600 knots closing." My question is; (1) That this only seems to be true when the Switch is in the 'BEAM' position, as the Target is clearly shown to be closing at approx 250 knots (2) That when the Switch is placed in the 'TAIL' position, the Target is now indicated as 'closing' towards me at approx 400 knots (even though his actual speed is still 250 knots, and 250 knots would fit into the scale of the 600 knot closure rate per TAIL Switch position) (3) That when the Switch is placed in the 'NOSE' position, the Target is now indicated as 'opening' away from me at approx 160 knots (even though his actual speed is still 250 knots (towards me), and 250 knots would fit into the scale of the 1800 knot closure rate per NOSE Switch position) * I have made a BLUE mark on both the TAIL and NOSE pictures to indicate where I would have assumed the Target closing DOT would be * ** To preempt, I'm not confused with the 'closure scale' on the right side of the DDD, as this is used when an STT Lock is made and clearly shows 'total closure rate' with the target - and works as advertised... I'm looking forward to some clarification.. Thanks in advance Edited March 28, 2019 by The_Bullet_Chef
MBot Posted March 30, 2019 Posted March 30, 2019 (edited) I am still rather confused about the left and right scale and the relationship between the Aspect and Vc switches. According to the manual, Vc should change the scale in pulse doppler search mode, but it does not seem to have any effect. The switch changes the right scale in STT though. Edited March 30, 2019 by MBot
Pally Posted January 13, 2020 Posted January 13, 2020 (edited) Target Ground Speed Scale up/down shifts in DDD. THANK YOU for sharing this discovery. It caused me some grief thinking that how come the left scale in DDD (be it in search or STT mode) are not proportionally divide. :cry: Well, you got it right. :thumbup: It is 600 knots per tick, and each tick shifts up or down depending on ASPECT switch position. To illustrate once more, per your findings, (recalling each tick mark is 600 knots) that when ASPECT switch is set from BEAM to TAIL (remember BEAM is +1200 top most, -1200 is bottom most, and 0 occupies center) that the entire number line shifts upwardly; therefore, the former BEAM +1200, +600, 0, -600, -1200 knots become their respective TAIL +600, 0, -600, -1200, -1800 knots. This shift essentially "bumped" the BEAM +1200 knots off the top to become a TAIL +600 knots, while it also drags upwardly the BEAM -1200 knots from the bottom to become a TAIL -1800 knots. Thank you, again! Edited January 13, 2020 by Pally Added my own notes, credit to The Bullet Chef for original content.
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