[WIP] SJ Radar Mod version 2

[Nisgeis]

First radar mod seems to have worked OK, but there are a few issues with it, which I wanted to fix but thought I would release a workable version, before trying anything more dramatic. I have ideas about how to do all of what is below, but I haven't tested the concept yet, as at the moment I don't have the skills to do this yet. I'll learn as I go. I understand from reading the very long post about the bearing line / range ring mod that was released for patch 1.2 was pretty much killed by patch 1.3. This patch hid the grid texture used somewhere inside the engine so it couldn't be fiddled with and the stock bearing numbers were a permanent feature. This broke peoples custom grids which they had all worked very hard on. They also decided that it was not possible to add in arced contacts, due to the way the radar contact graphics were stored. I hope to make some good progress with this and here's what's planned for version 2 of my radar mod.

• Increase resolution of the radar screen. (Complete)
• Remove stock bearing numbers. (Complete)
• Add high resolution circular bearing numbers round the outside of the scope (needs above completed).
• Add a zoom function to the radar screen for easy viewing of the scope). (Complete)
• Add high resolution bearing lines in 10 degree increments.
• Add high resolution range rings, steps to be determined 10%?
• Stop contacts appearing ahead of the sweep.
• Remove sweep line?
• Change the contacts so that they appear arced, instead of blobs.
• Add a digital range readout.
• Add a digital bearing readout.
• Change max range from 80,000 yards to 40,000 yards.
• Leave A-Scope Unaffected. (Failed so far)

I know the range change isn't historically accurate, but from testing it seems you can only pick up targets within the 20 nm (approx 37km) viewing sphere, I used the biggest radar return I could get my hands on, the Yamato, parked them all at set distances and the greatest range I got was just over 37,000 yards, which I could maintain up to just under 39,000 whilst backing off the target. I think it makes more sense to use a maximum range that is workable and useful.

As far as I can tell, the radar beam was 5 degrees wide, so any target should be at least an arc of 5 degrees. targets at the same range and with less than 5 degrees seperation should appear as an arc of greater than 5 degrees. I was pleasantly surprised to see that the game appears to model ships being obscured by other ships between you and the ship in question, so it does not appear on the scope.

I don't currently know if the radar sets had a beam sweeping the scope as currently depicted. All the pictures of WW2 era sets I have seen do not appear to have a sweeping beam visible. If someone could shed light on this, it would be appreciated.

I decided to include a digital bearing readout (if possible) in lieu of a bearing train indictaor easily visible. There is one on the wall above the A-Scope, but it's not easy to get at, as if you move to the A-Scope from the PPI, the radar man starts sweeping and you have to be really quick to get a halg decent bearing reading. Digital range readout to hopefully be accurate to within 0.2% of actual distance. Range and bearing info may be diffult to read at extremely close ranges, due to radar lobes.

I'm hoping to make these changes and leave the A-Scope undisturbed, but it might not be possible. It might not be possible to get all of my hoped for changes active, but one has to have goals right?

[Nisgeis]

Here's what I have so far, stock bearing numbers removed and ready for additional lines to be added. You can't see, but when you zoom in, it's got clean thin precise lines now. I'll add more lines soon.

Great idea with the Zoom option nesgais.

Could you write the values to enter into cameras.dat for that. Then ill include the zoom into my next cameras.dat mod.

[LukeFF]

Nice progress there! I'm looking forward to seeing what you come up with. As to your question about a beam sweeping around the scope, check out this picuture:

http://www.usscobia.com/P2050014.jpg?%22

Near the top of the screen you can see the radar contact the scope is picking up. Intersecting that contact is the the beam of the radar.

[Fish40]

Nice going! Keep up the good work!

[gimpy117]

my gramps said that they had a freined or foe do hickey on those things? is he right or is it just the fact that it was 65 years ago??

here's what wikipedia says:
"The IFF of WWII and Soviet military systems (1946 to 1991) used coded radar signals (called Cross-Band Interrogation, or CBI) to automatically trigger the aircraft's transponder in an aircraft "painted" by the radar." -wikipedia.org

[Nisgeis]

Originally Posted by Mav87th

Could you write the values to enter into cameras.dat for that. Then ill include the zoom into my next cameras.dat mod.

Using S3D, either add from scratch, or copy using export the Optical node and properties from either of the periscopes and change the zoom levels to 1 and 3, which should be OK for most resolutions.

[Nisgeis]

Originally Posted by LukeFF

Nice progress there! I'm looking forward to seeing what you come up with. As to your question about a beam sweeping around the scope, check out this picuture:

http://www.usscobia.com/P2050014.jpg?%22

Near the top of the screen you can see the radar contact the scope is picking up. Intersecting that contact is the the beam of the radar.

i must have looked at that pic dozens of times and never even noticed the contact at the top, or the beam line. It looks like it's not a moving beam though as it looks very narrow - about 1 degree wide, or less. So... from that I'm going to take it that the radar scope will draw 1 degree at a time, but the actual radar beam will detect in a 5 degree arc, so that contact should be arced if the beam were moving. I'd post a pic of the arcs from other pics, but photobucket is down for maintenance at the moment.

[Nisgeis]

Originally Posted by gimpy117

my gramps said that they had a freined or foe do hickey on those things? is he right or is it just the fact that it was 65 years ago??

here's what wikipedia says:
"The IFF of WWII and Soviet military systems (1946 to 1991) used coded radar signals (called Cross-Band Interrogation, or CBI) to automatically trigger the aircraft's transponder in an aircraft "painted" by the radar." -wikipedia.org

Was your grandfather in the submarine service and what was his role? Sounds interesting! IFF was developed before WW2 and was in widespread use during the Battle of Britain (1940). The early units were standalone units, later developments were incorporated into the main radar assembly. The IFF interogator would send out a challenge and the unit in the aircraft or surface ship would automatically respond with the correct response, which would then be displayed on the IFF display. As surface ships had the ability to find, track and destroy targets without being able to see them, it became important to have a means of identifying the target with no visibility.

Here's an extract from the war patrol of the USS Baya May 5th 1945:

1236 SD radar contact on B-24 at 20 miles (plane contact no.30). Plane closed to 15 miles and then lost at 20 miles.
1344 SD radar contact at 11 miles (plane contact no.31) No IFF. Plane closed to 9 miles.
1345 Made quicik dive.
1411 Surfaced, all clear.

From what I have read, there was a Mark 3 IFF system in use that would display the IFF signal as a dot and dash contact on the PPI display, instead of the usual solid arc, identifying it as friendly.

The SJ radar was for other things. Because of its highly directional beam, it could be used as a point to point communications tool, without much risk of your transmissions being intercepted. A telegraphy key was attached to the set and the radar pulsed in morse to send a message. The radar operator would also wear headphones so he could hear the pulses and he could also hear the frequency of enemy radars, helping him to identify the type of radar it was.

Originally Posted by Nisgeis

Using S3D, either add from scratch, or copy using export the Optical node and properties from either of the periscopes and change the zoom levels to 1 and 3, which should be OK for most resolutions.

OK Zoom levels of 1 and 3 - got it

[M. Sarsfield]

Batfish has her IFF unit in the con near the trim valves. They used to have an explosive charge built into it, in case the boat was going to get captured. The Batfish still has the black contact switch mounted to the forward persicope shear to set off the charge - looks like the alarm contactors with a different knob.

[AlmightyTallest]

Is there any way we could incorporate IFF into our sim? Perhaps if a ship had an IFF system it could be plotted on the map as a friendly unit, or unknown, or additional info about the specific unit detetectd (Destroyer) (Aircraft Radar Friendly) (Aircraft Radar Enemy) etc at beyond visual ranges.

[M. Sarsfield]

I would think that if he finds a way to change the symbol on the radar scope to mark a friendly, then adding text shouldn't be a big deal.

[Nisgeis]

Targets already are plotted on the map as friendly (blue), neutral (green) or enemy (red) and unknown (grey). I can't think of a way to get the information from the game that a unit is friendly or not for display on the radar. That's out of scope (no pun intended) of this mod at least.

[M. Sarsfield]

I don't think he wanted it on the radar display like modern radar screens. He wanted the information transferred to the map. So, if it's a friendly radar contact, it shows up as a blue icon on the charts.