[X] My Assistant

[jmknapp]

I've been working on a web utility to extract pointing, geographic and other info from raw images. There are still a few kinks, but here's a beta version of the tool:

Cassini ISS raw image analysis tool

If you put in an FEI image ID (from the Cassini raw images website), it will determine the time of the observation, pointing, geographic intersection, etc. as well as a map projection with latitude/longitude lines.

If you have an interest, check it out & let me know if some changes/additions could be made to make it more useful for what you might be doing with the images.

[elakdawalla]

I've been working on a web utility to extract pointing, geographic and other info from raw images. There are still a few kinks, but here's a beta version of the tool:

Cassini ISS raw image analysis tool

Two words:

You rock.

I'm curious how you relate the FEI image ID to the observation -- are you building some kind of lookup table manually or is there information about that somewhere?

--Emily

[jmknapp]

I'm curious how you relate the FEI image ID to the observation -- are you building some kind of lookup table manually or is there information about that somewhere?

No lookup table as far as I know--this app is an exercise in reverse engineering. From the FEI id I can do a screen scrape of the Cassini raw images site to get basic info including the distance from the target. The distance is then used to determine the time of the observation; once the time is known the SPICE kernels can be used to determine the geometry and all kinds of other neat stuff.

I once asked the Cassini website contact if they would please provide the time of the observations (since they obviously have it somewhere for use by their search engine) but never got a reply.

[elakdawalla]

I once asked the Cassini website contact if they would please provide the time of the observations (since they obviously have it somewhere for use by their search engine) but never got a reply.

I have just heard from one of my friends there that the request for the inclusion of times was made, but was denied.

--Emily

[jmknapp]

I have just heard from one of my friends there that the request for the inclusion of times was made, but was denied.

That's too bad... I wonder why they won't provide that? Maybe if more people expressed interest? http://saturn.jpl.nasa.gov/news/contact-us.cfm

As it stands, figuring out the time from the distance information is very tricky & can fail because the quoted distance on the Cassini website sometimes doesn't jibe exactly with the SPICE prediction & so the lookup fails.

The tool does this:

* get target, date and distance from the Cassini raw images website
* use SPICE to figure out the time(s) on the given date the target was at that distance (there may be more than one time during the day when this is true)
* for each candidate time, query the Cassini web site search function to see if the raw image comes up for that time (+/- 1 minute)

So if there is a discrepancy between SPICE and the website, none of the queries match and the tool returns "File xxxxx not found."

Sure would be nice to just get the time of observation directly. Failing that, at least the tool return results for most of the images.

[canis_minor]

That's too bad... I wonder why they won't provide that? Maybe if more people expressed interest?
...
Sure would be nice to just get the time of observation directly.

I agree, and feel free to make more requests. The problem is, if the Cassini public site posts the precise time of the images, then some "bad apples" could use that information, to do a lot more scientific analysis with the JPEGs and try to publish ahead of the ISS team. This struck me as a bit paranoid, but I actually heard recently that a scientific paper using JPEG images (not a good idea) was indeed published without coordination and collaboration with ISS. So from a certain perspective, their desire is reasonable.

In a perfect world, we wouldn't have to go through this crapola.

*Sigh*