I noticed that some things are simply passing under the radar, for they aren't 'sexy' enough and don't find multipliers who disseminate the information. Even people with great attention to military affairs, including insiders, often don't know about developments 10-30 years old even if those were not kept secret. This is particularly common regarding electronic warfare and surveillance technologies, but it afflicts even seemingly simple things such as mortars.
Here's one snippet that may close one such gap. Infrared illumination by mortar bombs and howitzer shells. The first generation of low light sensors depended on illumination searchlights. Some of the earliest examples are presented >>here<<.
Such illumination searchlights were still in use during the 1970's, particularly on tanks as gunner and driver aids at night. These devices work in the near infrared spectrum usually. Entirely passive devices that show the warmth of objects (and are useful even in daylight to find otherwise camouflaged vehicles and troops with ease) have become common in Western armies during the 1980's only, and for dismounted personnel during the 1990's. They're still rather expensive and rare as night sights for individuals as of today.
Instead, the typical rifle or helmet mounted night sight is a low light amplifying sensor that is sensitive enough to make do without an artificial illumination source usually. This misled many people to believe these would work well without any illumination, but they don't. They were called "starlight scopes" for a reason; at new moon or under dense clouds, far from civilian light sources and fires you won't see far with these. The availability of light sources coins the effective range.
The use of conventional illumination munitions is troublesome because these light amplifiers must not be pointed at an intense source of light (or be activated at daylight). The answer was to develop illumination munitions that are the typical flares on a parachute as known since the 18th century, but emitting light almost exclusively in the near infrared spectrum.
The slides below are excerpts from a presentation given in 2001 and show this technology:
The source document is here.
So in other words; there's some need for illumination munitions even in the age of night sights (in addition to batteries for the latter).
I included the third page for a simple reason: I did write a couple times about how infantry needs to be elusive, to not stay for long in some place once detected. My rule of thumb was to not stay in a detected position for longer than two minutes.
2011-08 On infantry (breaking contact)
The slide shows why; the potential for responsiveness is mortar (or artillery) fires within less than one minute. There are other lags in addition to this one, thus my rule of thumb of two minutes.
Please, form your own opinion on whether doctrines and equipment have evolved during the last 15 years in order to enable Western infantry to strike and vanish within two minutes routinely. Keep in mind how very much the attention was focused on occupation warfare where the opposing forces were devoid of even 1939-style mortar capabilities!