The problem with VHF radio systems is that they have very short range. The range is limited mostly by topological features such as building and mountains. For local people this is only a small problem as they will operate repeaters to overcome terrain, but disaster workers will not know much about the local conditions and so will find their communications to be very poor, due to the necessity to use simplex systems.
The answer may be NVIS. In this mode, the signal is fired straight up into the ionosphere and so returns straight down. It cannot be blocked by mountains or valleys. This makes it ideal for a convoy on the move for example. If one vehicle gets lost, it will not stray out of range. even if it looses line of sight by passing round the bend in a valley.
There are two problems with this mode. The first is that in order to bounce off the ionosphere, the frequency will have to be in the HF band, somewhere between 4-8 MHz approx. The actual best frequency depends on local and seasonal conditions. It also varies with the time of the day, so you need one frequency for daytime and another for night. The reliability is about 80% by day but can drop to low levels at night and be very poor at dawn, around 50%.
Another problem is that the antennae at this frequency tend to be physically large, so operating from mobile or portable stations is not at all easy. When operating with a fixed station then a simple dipole, about 6 feet off the ground is best, but for mobile operation you have to either bend your whip over the vehicle horizontally, or even ground it at one end making the antenna into a magnetic loop. Or you can use a magnetic loop antenna with the elements in the horizontal position.
DRCF proposes to look into a suitable antenna system which can be efficient at NVIS frequencies while can still be packed into a small space for transportation. This will give what disaster communicators need. Something with a 200 mile all around range, for communicating with the field. Something which is independent of ground infrastructure such as repeaters, and which will be independent of terrain of which the users may be unaware.