need evidence Aim-7 Wrong parameters such as HOJ... ?

[Jar72]

Dear ED teams,

I have seen recently a post regarding incorrect mass after recent API update. I took the liberty to further dig into the subject after being hit by shots in HOJ mode by F-4 with Aim-7F. The F-4 was notching at 90-110° (so no lock on me) and I still got hit without RWR warning. Track is 90 Mb, so I can share with separate file if needed.

My understanding is that irl HOJ (without aircraft guidance) is functional on -MH and -P versions only. But it seems -F and -M are equipped with HOJ also. I looked into the file "aim7_family.lua" and found the line "hoj = 1" for all these versions. I guess this explains it.
 

By doing comparison on data (I tried to reverse engineer to understand, but I don't to be honest), I also found differences on other parameters. On versions -M and -MH, there are parameters set as "sensors", with height error lower than on "seekers" parameters. I assume these are for shorter distance, with better guidance or proximity fuse. The "sensors" parameters do not exist for the -P.

Also, same reasoning for paramerters such as "gimbal" and "ap", they are not there for the -P.

 

So I guess missile -P has a default behavior for these missing parameters, and thus behaves worse than -M and -MH in specific areas. Areas that I don't know about.

I am not sure if all this is correct, nor do I know if that is realistic. But I saw it, so I thought I could raise it and maybe help to fine tune the missiles without too much workload, that is: removing hoj for -F and -M, and adding the missing parameters for -P. If that is indeed correct.

Thank you very much in advance for taking care of Fox-1, many cold war enthousiasts like me appreciate it very much.

JAR.

Example

Aim-7 M

    sensor = {
        delay                        = 0,
        op_time                        = 80,
        FOV                            = math.rad(12),
        sens_near_dist                = 100,
        sens_far_dist                = 60000,
        ccm_k0                        = 0.2,
        aim_sigma                    = 4.0,
        height_error_k                = 25,
        height_error_max_vel        = 60,
        height_error_max_h            = 300,
        hoj                            = 1,
    },

 

    seeker = {
        delay                    = 0.6,
        op_time                    = 75,
        FOV                        = math.rad(120),
        max_w_LOS                = math.rad(20),
        sens_near_dist            = 100,
        sens_far_dist            = 30000,
        ccm_k0                    = 1.0,
        aim_sigma                = 5.5,
        height_error_k            = 100,
        height_error_max_vel    = 138,
        height_error_max_h        = 300,
        hoj                        = 1,
    },

aim7_family.lua

Edited September 14 by Jar72

[Zergburger]

ED will probably ask you for some sort of source documentation for how you know -F and -M model sparrows did not have HOJ capabilities, so if you intend on seeing this through you may want to get those docs ready

[BIGNEWY]

Hi, 

I can mention it to the team, but they will ask for evidence to support any claims. 

Track replay of tests may also help. 

thank you 

[Jar72]

Thank you.

 

Regarding the HOJ, I'm sorry, after several evenings of research, I cannot find any official information. I took it for granted as many many peole mention it, but I have no evidence to show.

Edited September 18 by Jar72

[DSplayer]

On 9/15/2025 at 5:12 AM, Jar72 said:

Dear ED teams,

I have seen recently a post regarding incorrect mass after recent API update. I took the liberty to further dig into the subject after being hit by shots in HOJ mode by F-4 with Aim-7F. The F-4 was notching at 90-110° (so no lock on me) and I still got hit without RWR warning. Track is 90 Mb, so I can share with separate file if needed.

My understanding is that irl HOJ (without aircraft guidance) is functional on -MH and -P versions only. But it seems -F and -M are equipped with HOJ also. I looked into the file "aim7_family.lua" and found the line "hoj = 1" for all these versions. I guess this explains it.
 

By doing comparison on data (I tried to reverse engineer to understand, but I don't to be honest), I also found differences on other parameters. On versions -M and -MH, there are parameters set as "sensors", with height error lower than on "seekers" parameters. I assume these are for shorter distance, with better guidance or proximity fuse. The "sensors" parameters do not exist for the -P.

Also, same reasoning for paramerters such as "gimbal" and "ap", they are not there for the -P.

 

So I guess missile -P has a default behavior for these missing parameters, and thus behaves worse than -M and -MH in specific areas. Areas that I don't know about.

I am not sure if all this is correct, nor do I know if that is realistic. But I saw it, so I thought I could raise it and maybe help to fine tune the missiles without too much workload, that is: removing hoj for -F and -M, and adding the missing parameters for -P. If that is indeed correct.

Thank you very much in advance for taking care of Fox-1, many cold war enthousiasts like me appreciate it very much.

JAR.

Example

Aim-7 M

    sensor = {
        delay                        = 0,
        op_time                        = 80,
        FOV                            = math.rad(12),
        sens_near_dist                = 100,
        sens_far_dist                = 60000,
        ccm_k0                        = 0.2,
        aim_sigma                    = 4.0,
        height_error_k                = 25,
        height_error_max_vel        = 60,
        height_error_max_h            = 300,
        hoj                            = 1,
    },

 

    seeker = {
        delay                    = 0.6,
        op_time                    = 75,
        FOV                        = math.rad(120),
        max_w_LOS                = math.rad(20),
        sens_near_dist            = 100,
        sens_far_dist            = 30000,
        ccm_k0                    = 1.0,
        aim_sigma                = 5.5,
        height_error_k            = 100,
        height_error_max_vel    = 138,
        height_error_max_h        = 300,
        hoj                        = 1,
    },

aim7_family.lua 57.44 kB · 6 downloads

I will note that it seems like the AIM-7 seems to be in the progress of being ported to a new schema and some of the newly added code blocks don’t do anything with the current schema that it uses. I believe the additional height error values you’ve added don’t do anything and they already exist in other code blocks (seeker block is used and not sensor with the current schema).