Radar

[Berserker]

Is there a way to shut down sd and sj radar?? One at a time without shutting down both..

[propbeanie]

In Stock, no. SD is always on, unless you are underwater below RD (PD with mods), and if you have SJ, it turns on automatically when you surface - but there is a reason for that... waves...

In FotRSU, instead of an up / down for the SD, we use On / Off, so that you can approach any place, but especially home, and not be interrupted with "Radar contact..." That also helps if you are trying to "stealth" your way somewhere after dark. The SJ still turns on automatically when surfacing or at RD, but the reason being you do want it to come back on if a wave washes over it. But you can turn it of separately from the SD.

No matter the mod set, or Stock, always consult your SH4_Q-Ref_Card_Back.jpg and SH4_Q-Ref_Card_Front.jpg images in the game's root folder for the key combinations for both (and other stuff, of course).

[KaleunMarco]

Originally Posted by propbeanie

In Stock, no. SD is always on, unless you are underwater below RD (PD with mods), and if you have SJ, it turns on automatically when you surface - but there is a reason for that... waves...

In FotRSU, instead of an up / down for the SD, we use On / Off, so that you can approach any place, but especially home, and not be interrupted with "Radar contact..." That also helps if you are trying to "stealth" your way somewhere after dark. The SJ still turns on automatically when surfacing or at RD, but the reason being you do want it to come back on if a wave washes over it. But you can turn it of separately from the SD.

No matter the mod set, or Stock, always consult your SH4_Q-Ref_Card_Back.jpg and SH4_Q-Ref_Card_Front.jpg images in the game's root folder for the key combinations for both (and other stuff, of course).

while we are on the subject of Radar, why is it that in non-clear weather that Radar performs no better than Visual detection?
i have encountered numerous times, when the weather is between clear and rainy (light fog?), where a first contact with the enemy is well within the detection range of Radar...like range of 4000 yds. Much too close for an initial contact.

Radar should have picked up that contact much further out than 4000 yds.

is this lack of detection by Radar a game option or another example of Ubi design ineptitude?

[Macgregor the Hammer]

Originally Posted by KaleunMarco

while we are on the subject of Radar, why is it that in non-clear weather that Radar performs no better than Visual detection?
i have encountered numerous times, when the weather is between clear and rainy (light fog?), where a first contact with the enemy is well within the detection range of Radar...like range of 4000 yds. Much too close for an initial contact.

Radar should have picked up that contact much further out than 4000 yds.

is this lack of detection by Radar a game option or another example of Ubi design ineptitude?

Water (rain) & fog are excellent radar energy attenuators! A basic radar set doesn't have the power or the means to adjust for weather. Modern radars adjust frequency, change pulse repetition frequency and power when certain conditions appear in the returning signal. Newer radars can 'burn through atmospheric interference. Without computer controls, it's kind of crap shoot on what you're going get with the return signal.

The SJ radar used a very rudimentary magnatron for the output. The Brits invented the magnatron in the mid-thirties. The SJ set operated in the 2cm (4 Ghz) which is much better than the German sets which operated from 200-600 Mhz. Microwave is highly focused with very low dispersion. It was very high tech for it's day.
I think the radar model, which was tweeked by CapnScurvy is pretty close to real life.

I worked on fire control and navigation radar for the A-6 and F-4 in the Marines.

[KaleunMarco]

Originally Posted by Macgregor the Hammer

Water (rain) & fog are excellent radar energy attenuators! A basic radar set doesn't have the power or the means to adjust for weather. Modern radars adjust frequency, change pulse repetition frequency and power when certain conditions appear in the returning signal. Newer radars can 'burn through atmospheric interference. Without computer controls, it's kind of crap shoot on what you're going get with the return signal.

The SJ radar used a very rudimentary magnatron for the output. The Brits invented the magnatron in the mid-thirties. The SJ set operated in the 2cm (4 Ghz) which is much better than the German sets which operated from 200-600 Mhz. Microwave is highly focused with very low dispersion. It was very high tech for it's day.
I think the radar model, which was tweeked by CapnScurvy is pretty close to real life.

I worked on fire control and navigation radar for the A-6 and F-4 in the Marines.

so, the SJ performance that i experienced is normal for WWII?

i thought that radar could perform regardless of the weather, even in WWII.

[Macgregor the Hammer]

Originally Posted by KaleunMarco

so, the SJ performance that i experienced is normal for WWII?

i thought that radar could perform regardless of the weather, even in WWII.

Even today, heavy snow, rain and fog wreaks havoc on radar performance. That being said, not detecting a target until it's at 4000 yds. is rather strange. The radar antenna is not that high on the mast and if the boat is pitching in rough seas, yet another problem

The questions that come to mind:

Are you depending on your radar operator or interpreting the sweep yourself?

Are you using the PPI or A scope? Once you know what to look for, the A scope can give you much more accurate data. You can manually sweep the antenna using the home/end keys to zero in on a 'tent' in the weeds. I always wished SH included a J scope display. Much easier to interpret and very accurate. I guess radar is not radar unless you have the circular sweep.

Here's and apples to apples with the German sets:

SJ SJ-1 Characteristics:
Range: Varies with target: SJ ~8 miles SJ-1 ~12 miles
Peak Output Power: SJ 20Kw SJ-1 50Kw
The average expected error in range measurement: +/- 15 yards plus 0.1% range to +/- 40 yds
The average expected error in bearing measurement: is from +/- 2 to +/- 4 mils (+/- 1/10 degree to +/- 1/5 degree)


FuMO 30 Submarine Surface Search Characteristics:
Frequency: 368Mhz
Range: 6-8KM
Average Bearing Error: 100m
Accuracy: +-5 degrees.

[KaleunMarco]

Originally Posted by Macgregor the Hammer

Even today, heavy snow, rain and fog wreaks havoc on radar performance. That being said, not detecting a target until it's at 4000 yds. is rather strange. The radar antenna is not that high on the mast and if the boat is pitching in rough seas, yet another problem

The questions that come to mind:

Are you depending on your radar operator or interpreting the sweep yourself?

Are you using the PPI or A scope? Once you know what to look for, the A scope can give you much more accurate data. You can manually sweep the antenna using the home/end keys to zero in on a 'tent' in the weeds. I always wished SH included a J scope display. Much easier to interpret and very accurate. I guess radar is not radar unless you have the circular sweep.

we were patrolling, actually i think we were transiting to a new patrol area. when i do that, i rely on the radar operator and do NOT monitor the scope myself because the TC is limited to 32 or 64.
when i am transiting, the TC is usually 512 or 1024. Never higher.

but your point is that had I been monitoring the scope myself i would have seen blips at >4000 yards? if i can see that on the radar monitor why cant the AI operator see it and sing out with the Contact (rhetorical question)?

[propbeanie]

The "time" factor is why. Something has to hit the "threshold" for the game to respond for you. Depending upon the mod set, that might be altered from stock. Don't forget also that the game has that confounded "range" dial if you look at the PPI, which can throw you off if looking at the wrong scale... The nice, though non-historical aspect of the game's radar is that you do not get land reflections to interfere with reception and interpretation... Have you read CapnScurvy's "Using Radar_Sonar.pdf"?

[KaleunMarco]

Originally Posted by propbeanie

The "time" factor is why. Something has to hit the "threshold" for the game to respond for you. Depending upon the mod set, that might be altered from stock.

Time meaning:
[Radar]
Detection time=5
Sensitivity=0.01
Waves factor=1.0
Enemy surface factor=5.0
Thermal Layer Signal Attenuation=5.0

is there a user document that explains these variables?

Don't forget also that the game has that confounded "range" dial if you look at the PPI, which can throw you off if looking at the wrong scale...

not an issue. detection is the issue.

The nice, though non-historical aspect of the game's radar is that you do not get land reflections to interfere with reception and interpretation...

i have found that islands (land) will block radar reception.

Have you read CapnScurvy's "Using Radar_Sonar.pdf"?

yes, i have. unfortunately Scurvy's excellent piece does not cover the weather. my naval experience did not include any electronic sensor training and, as such, i expected radar to be able "see" through rain and fog. apparently i am wrong on that point, which is fine. call this a training opportunity.

[propbeanie]

Originally Posted by KaleunMarco

Time meaning:
[Radar]
Detection time=5
Sensitivity=0.01 Yes - all of them
Waves factor=1.0
Enemy surface factor=5.0
Thermal Layer Signal Attenuation=5.0

is there a user document that explains these variables?
the "; comments" in the file is all I know of... make a change, go watch


not an issue. detection is the issue.



i have found that islands (land) will block radar reception.
Somewhat. Like sonar, "land" is kind of "spongy", not always blocking. Zoom in and out some when you know something is on the other side of an island, and you'll see like a "ghost" of a contact. But actually, what I was referring to was that you do not see any "fuzz" or "interference static" on the PPI when in close to land, like you would on radar of that era.

yes, i have. unfortunately Scurvy's excellent piece does not cover the weather. my naval experience did not include any electronic sensor training and, as such, i expected radar to be able "see" through rain and fog. apparently i am wrong on that point, which is fine. call this a training opportunity.

Think about rain, or clouds (which are, after all, tiny little "rain drops" all bunched together), as little "prisms" that can take a signal, and either reflect it all back at you, or send some of it off this-a-way, and some of it off that-a-way, etc... degrades the signal. Sort of like listening to a 78rpm big band record on grandma's turntable, and comparing it to a modern digital rendition of the same thing, on a pristine studio monitor set-up... "There's a piano in that song?!!???!!!!"

[KaleunMarco]

Originally Posted by Macgregor the Hammer

Even today, heavy snow, rain and fog wreaks havoc on radar performance. That being said, not detecting a target until it's at 4000 yds. is rather strange. The radar antenna is not that high on the mast and if the boat is pitching in rough seas, yet another problem

The questions that come to mind:

Are you depending on your radar operator or interpreting the sweep yourself?

to re-answer the question: yes i rely on the radar operator to interpret the sweep.

however, in my current mission i was operating at TC 1 when a surface ship was detected at 7+ nm in a heavy rain/fog. there was no visual (lookout) detection.

so, based on just these two experiences documented here i would conclude that the detection at 4000 yds was probably due to a higher TC. if i had been operating at lower TC, my radar operator would have detected the bogie much further out than 4000 yds.

not sure how i will handle this in the future.

[Macgregor the Hammer]

KM--

This section of the wikipedia article does a great job of all the limiting factors with radar. These are factors with modern radar. You can imagine what a rudimentary set like the SJ was trying to deal with.

https://en.wikipedia.org/wiki/Radar#Limiting_factors

Hope it helps....

MacG