Where does the term "Blutz Waves" first come from? Trying to determine if this originated with GT, in a manga, an interview or I just missed hearing it in DBZ. As far as I'm aware the only discussion in DBZ and earlier referred to them simply as moon light.
To add a bit of backstory. Blutz Waves are defined as the following


  An energy source emitted by large celestial bodies such as a full-moon or the Earth when it reflects rays of sunlight. They are alternatively called Bruits Rays, Fruits Rays, or Green-spectrum Radiations (in the English manga). When a Saiyan absorbs at least 17,000,000 zenos (ゼノ Zeno, unit used to measure waves of full celestial light) through the retina,[1] a reaction occurs in the tail that causes the Saiyans to transform into ruthless Great Apes. If a moon is not present, the Saiyan, if he/she knows how to use it, can also create an artificial moon to allow themselves to absorb the necessary amount of Blutz Waves needed for them to go Great Ape to compensate.


Note that this concept of B.Waves existed in the manga, of DBZ in the saiyan arc. It was explored a bit heavier in GT and the term Blutz Wave was only used in GT but the concept was introduced as early as Dragon Ball but unexplored.

In Dragon Ball Z Gohan and Goku both had adverse reactions to seeing the attack ball(the ship Goku came to earth on) in the first arc against Raditz. Goku mentioned it felt familiar and Gohan flat out cried on site.

The attack balls used a similar form of the technology to produce artifical moons to trigger the reaction in combat. This is elaborated on further here: 


  Spaceships used by those under King Cold, Cooler and Frieza for interstellar travel. When the Saiyans were a part of the military, these vehicles also sent low-class Saiyans to distant locations, so that they would one day conquer and destroy worlds throughout the galaxy.


In short the moon simulator was kind of a last ditch defense given that the saiyans they send around flying at Faster than light speed for between 1-3 years are kept in suspended animation. If they were to be attacked immediately after exiting their ship they may have a hard time defending themselves. 

The saiyans were also known for sending infants to conquer planets,the moon simulator for the transformation helps to aid that. 

In summation

The concept has been around since the original DB and is cannon the concept being that moon light from a full moon makes saiyans transform, the term blutz wave came out of GT and is not cannon but it extends the concept with a term and definition. The story of why the ships had simulation engines to product moonlight/blutz waves is cannon and given that it comes with different details from Vegeta and Bardock. Bardock being a movie character but confirmed as cannon.

Though with super out and more saiyans on the scene. There might be a new term and explanation that comes out making Blutz waves a full on full non-cannon detail.