HiRise Image Orientation?, What does it mean when North is not at 0 degrees? Options

[Bobby Richardson]

HI everyone.

I've been following MSL's meanderings since Day One, but I still find myself going to HiRise.

I just realized that on the HiRise image info pages they list the map-projected & non-map projected North Azimuth at some angle other than 0 degrees; e.g., 'Map Projected North Azimuth - 274'. 'Non Map Projected North Azimuth - 103' And yet, when I overlay either HiRise image on Goggle Mars, a line drawn parallel to the sides of the imaged surface will extend up to the North Pole.

Does this mean that Map Projected North is located toward the left side of the image instead of toward the top, and Non-Map Projected North is toward the right side of the image? And if so, what's up with the GM overlay?

I hate to bother ya'll if this is a really 'duh' question, but my google-fu just isn't as strong as I thought it was.

TIA
Bobby R.