is there a difference between being a norse pagan and a asatru?

i have been researching and wondering about the difference between them because they seem to have the same principles and gods but are they the same in all aspects?

Norse pagan is a more open term. Asatru has specific rites and ideas that not all Norse pagans embrace.

I have Viking blood in me

Yes, that's it, Neo-Viking beliefs! Coined a new term there!!

Norse Pagan describes anything from the range of Nordic pagan beliefs, modern day to ancient times and a number of modern faiths. Asatru may be termed a Norse pagan faith, so that's probably where you're getting the "similarities"... kinda like how Wicca has a lot of "similarities" with paganism since Wicca is a pagan religion, but paganism is hardly defined by Wicca.

Asatru, so I understand it, is a specific religion dedicated to a particular grouping of Norse deities (the "air" Gods, whereas the "Vanatru," if I have my heathery right, refers to the "earth" deities of the same mythology system.)
-Scarlet

I would describe someone who is Asatru as someone who worships the Aesir, the ancestors and honors the land watter within their cosmology. (I.e. they're not worship ping Freyja as the Lady of Wicca, they believe in the nine worlds, and look for values from the ancient Prue-Christian culture that worshiped these ancient Gods).

A Norse Pagan however can worship the Norse Gods, in a variety of ways that may, or may not reflect the cosmological worldview and cultural context of the ancient Prue-Christian culture. A Norse Pagan may also ignore the ancestors and the land watter and only honor the Norse Gods.

So, someone who is Asatru could be considered a Norse Pagan, but not all Norse Pagans are Asatru. Think of it like this, just as there can be multiple denominations within Christianity, there's a multiplicity of people who work with the Norse Gods, but in varying ways.

It can be a bit confusing, and sometimes even if you 'poll' a number of folks you can get very different answers on what the terms mean and the nuances between them. There's a number of terms that fall under the 'umbrella'. You may find this somewhat helpful: http://www.patheos.com/community/paganportal/2010/10/22/wyrd-designs-understanding-the-words-%E2%80%93-asatru/