Now about using nano-gas to locate stealth plane and stealth projectile such as glide bomb, a brother sometime ago said that if the body of stealth plane is damaged by shrapnel then it looses it's stealth ability (smooth surface). Also if you make this nano gas have ability to stick to surfaces (by electro-static charge) or by actually being sticky! Then plane or glide bomb that travel through this becomes visible as well as having chance of being visible on doppler radar! Dispersion at altitude above target will ensure the glide bomb has to travel through this!
Yes, if you stick non Stealth matter (such as metal particles) to Stealth Aircraft body then you will see it on Radar.
JDAM bomb is always visible on Radar since it is made of metal. There is no need to spray metal aerosol (suspension of fine solid particles or liquid droplets in a gas) on JDAM in order to see it on Radar.
Metal particles might be of micro meter size and not of nano meter size. That gives us "micro gas" and not a "nano gas".
And nomad, you do not need to wait until JDAM explodes to see other JDAMs and Aircrafts that dropped them. You can always detect approaching JDAM or Aircraft with Infrared Thermal camera or Phased Array Radar.
In theory the easiest way to detect Stealth Aircraft is to use long wavelength Nebo SVU Radar or Infrared Thermal camera. I do not know if Russians proved Nebo theory with actual detection of Stealth Aircraft. But there was video on Internet showing Igla Infrared Thermal guided missile shooting down Predator UAV. Predator is similar to Stealth F-22/F-35 in materials its made of and heat signature (but not completely Stealth).
Also High Explosive rounds on Parachute are not a good solution since they glide down the ground losing the correct interception position. To intercept missile AA gun round should be placed in exact correct position in front of approaching missile and then exploded to destroy the missile. Constantly gliding down rounds are useless. They will not be in correct interception position.