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I don't think this is intended behavior, but I could be wrong Steps to reproduce: Switch to A-G master mode Set FCR to GM Set FCR to NORM mode With azimuth set to 60, observe time it takes to scan: roughly 2.5 seconds With azimuth set to 30, observe time it takes to scan: roughly 1.5 seconds With azimuth set to 10, observe time it takes to scan: roughly 0.5 seconds This seems normal, there's a smaller area to scan so it takes less time Switch to EXP, DBS1 or DBS2 mode With azimuth set to 60, observe time it takes to scan: roughly 5 seconds With azimuth set to 30, observe time it takes to scan: roughly 5 seconds With azimuth set to 10, observe time it takes to scan: roughly 5 seconds Observed result: When changing the scan area, the time it takes to scan stays the same. Expected result: The same as NORM mode. The scanned area is smaller between azimuth set to 60, 30 and 10, so it would make sense that 30 updates quicker than 60 10 updates quicker than 30 ground_radar_bug.trk
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With FCR GM (or GMT, SEA) and AUTO scale set the range should decrease and increase based on cursor position according to the following rules: Increase when cursor range is greater than 95% current range setting Decrease when cursor range is less than 45% current range setting for cursor laterally centered, less for cursor laterally displaced Equation for range of decrease is 45% times cosine of azimuth, i.e. Azimuth Range 0° 45% 10° 44% 20° 42% 30° 39% 40° 34% 50° 29% 60° 22.5% F16 GM AUTO scale not decreasing.trk
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Hi everyone, Currently the F-16's air-to-ground radar has an overexaggerated radial footprint; the radar is able to display everything from basically ownship out to the extremes of the instrumented range and is able to do this regardless of antenna elevation angle (even with the antenna 60° above the horizon) or altitude. Generally speaking, if the aircraft's altitude increases and the antenna elevation angle below the horizon increases, the smaller the footprint that the radar covers. They say a picture speaks a thousand words so here's a diagram, that should more clearly illustrate what I mean: In the F-16CM, the AG radar makes a 1 bar scan, with a bar corresponding to ~5° in elevation (determined through simple trig in the air modes). At an altitude of 20,000 ft, with a 15° look-down angle should give me a patch between ~10 and ~15 nmi. Of course, the radar doesn't just have a mainlobe, it also has sidelobes, so the patch shouldn't abruptly terminate at those values but the brightness will gradually fall off to 0 (exactly how large it should be in total and how much it falls off by will depend on the radiation pattern of the antenna). This can kinda be seen in this video (only here the elevation angle below the horizon is very small and the altitude is ~14,500 ft), you can see that the gain reduces gradually around ~27 nmi and there are no returns closer than 25 nmi (corresponding to an elevation coverage of about 3.5° - well within the range of a 1 bar scan). However, in DCS, the footprint is currently unaffected by both altitude and elevation, leading to it being drastically overexagerrated (and even including areas the radar shouldn't even be able to illuminate with its mainlobe). If I'm flying at 20,000 ft I can see everything from 0 - 80 nmi with everything at constant brightness (obviously brightness of specific objects will depend on their RCS), regardless of the elevation angle. In order to do this the radar would have to be able to scan an elevation angle of ~88°, way beyond what the radar should be able to achieve with a 1 bar scan. Incidentally at 20,000 ft it shouldn't even be possible to see returns (apart from sidelobe returns, which should be more dim) inside of ~6 nmi, as the radar's elevation limits are ±60°. Another related issue (not sure if this should be in a different thread) is that the radar doesn't seem to respect the elevation setting that well - if you dial all the gain all the way up and tilt the antenna elevation above the horizon to it's maximum, the image appears like it would normally if I turned the gain down. Go all the way to 60° down and the whole image goes more or less dark, despite the fact that the radar should be illuminating a section with its mainlobe. Essentially the antenna levation setting seems to behave as if it were a 2nd gain setting for the entire image. APG-68_AG_coverage.trk