CTX images are using linear position interpolation instead of hermite

[jessemapel]

ISIS version(s) affected: 4.1.0 (likely 4.0) and later

Description

When spiceinit'd with ISIS 4.1.0, some CTX images are using linear position interpolation instead of cubic hermite splines. This is causing errors on the order of a few meters vertically. Currently we've seen this with J03_045994_1986_XN_18N282W and J03_046060_1986_XN_18N282W so far. It is likely occurring in more images.

How to reproduce

Spiceinit the cube with ISIS3 and then spiceinit the cube with ISIS4. The InstrumentPosition CacheType will be HermiteSpline under ISIS3 and Linear under ISIS4.

Possible Solution

This is likely caused by the cache being significantly smaller when ALE creates it compared to ISIS.
Additional context

[kberryUSGS]

This is happening with HRSC images as well, and based on where this is happening in the code, I'd expect it to happen with any LineScanner in ISIS.

[AndrewAnnex]

@jessemapel can you confirm this issue is fixed as of 4.2.0, unfortunately Ames stereo is locked to 4.1.0 at the moment

[jessemapel]

Just tested and it is still failing. Putting this on the todo list for next week :(

[jlaura]

@jessemapel Is this on the list for this week or should I pull this as a candidate for the support sprint?

[jessemapel]

@jlaura Put it in for support at this point. I don't think we'll have time to get to it this week.

[jessemapel]

Okay, confirmed this is fixed, but it just missed the 4.2 code freeze by 1 day. So, this will be out in 4.2.1 and 4.3.0