When dealing with commercial UAV work in Canada most operators typically deal with daytime flights, which are the more standard use case, and the more typical applied for under the SFOC process. However there are those jobs that require night time operations as well, and fortunately the Canadian Transport Canada regulations do allow for these.
These are stated in the SI 623-001 document as follows:
Conditions for Night VFR Flights:
Where the UAV is equipped with lights, the UAV pilot shall ensure that they are on at all times during night operations.
Where the UAV is not equipped with lights, the UAV pilot must ensure that there is a means of illumination during night operations, sufficient to maintain visual contact with the UAV.
A suitable portable emergency light source shall be available to the crew members when the aircraft is operated at night.
The pilot operating the UAV at night must not suffer from the visual limitations of depth perception, colour blindness or lack of visual acuity in low light conditions.
Visual observers providing the sense and avoid function during night operations are prohibited from using night vision goggles.
Also the SI states the following regarding LEDS and Night Vision Goggles:
6.5 Light Emitting Diodes (LED) and Night Vision Goggles (NVG) Limitations for Night Operations
For the most part they are fairly straight forward. Basically the UAV must be lit in order to maintain proper visual contact, the same as would hold during daylight use. This could be through lights on the aircraft itself or from external light sources along the flight path and focused on the aircraft.
Operating procedures and processes will need to be defined to account for the lighting requirements for night operations to be included as part of an associated SFOC application, as TC needs to establish that acceptable methods of making the UAV visible so as to maintain adequate VLOS are in place.
When dealing with night operations extra care should be taken to account for all possible hazards as part of the site survey process, since visual reference to the surroundings will be limited during the actual flights. Additional observers and spotters can be a great aid as well and where possible key structures should also be lit.