The danger of VFR flight into IMC is flying into clouds when you aren't properly trained for it. Icing generally only occurs in clouds between -20°C and +5°C. NEXRAD shows precipitation intensity, though, not clouds, so it doesn't really help avoid either of those things.
Regarding why NEXRAD isn't 3D, precipitation almost always falls to the surface, so ...
There is not much gained by the third dimension for your use case. In GA you generally want to avoid any active weather. Why make it more complicated?
can't go over it (performance limited)
can't go under it (microbursts can kill you)
=> only way is to go around it and therefore no need for that 3D information.
The display depends on the equipment used. For example, the Avidyne 540 Pilot Guide says this:
For Mode-S equipped aircraft, the aircraft ID (e.g. tail number, call
sign, etc) may also be displayed adjacent to the traffic symbol.
Normally I see a solid white diamond with a dotted line leading away to indicate direction, + or - how many hundreds of ...
ADS-B is part of a system that compromises a number of different things. ADS-B (In) means that your aircraft is capable of receiving the ADS-B data, FIS-B and TIS-B as well. FIS-B broadcasts information such as weather. TIS-B is a traffic broadcast system.
ADS-B includes a number of messages (about 27 different messages), including:
My question was due to the confusing mention of ADS-B in what was supposed to be either TIS-B or ADS-R.
I've now confirmed that the text on ICAO Doc 9871 Version 2 I quoted was due to a error.
In fact DO-260B, and even Doc 9871 Version 2 at table C-37 specify that TIS-B CF=4 is "Fine TIS-B message, AA field contains a 24-bit anonymous aircraft address".
Ground stations only send ADS-R/TIS-B messages for targets within a certain distance horizontally and vertically of ADS-B targets with the CDTI (Cockpit Display of Traffic Information, aka "ADS-B In") flag set. Assuming your CDTI flag is set correctly, the targets you're missing probably aren't close enough to qualify.
ADS-R is only used for relaying ADS-B messages from one datalink to another, e.g. 978UAT to 1090ES. This is currently only applicable to the US since no other country has adopted 978UAT.
TIS-B is used when a ground radar station transmits ADS-B messages on behalf of a non-ADS-B contact. If the contact has Mode S, the ground station will use the contact's ...