Extracting asc/descending tracks in high latitudes (regions 4 and 11)

[s2002365]

Hi! It would be great to develop a way to extract just ascending or descending tracks when downloading data with icepyx from regions 4 and 11 (highest latitude regions). Currently every granule in these two regions contains both ascending and descending tracks, but since we know which tracks are which it should be possible to distinguish them somehow at the point of order/download. @tsutterley had suggested separating the pieces by splitting at the minimum latitude. Open to suggestions and up for collaborating with others to implement this.

[weiji14]

Hi @s2002365, thanks for opening up this issue! Just so I can understand the use case for this, is the separating of ascending/descending tracks meant for helping with crossover analysis or something?

Also, are you thinking of using this for ATL06 or ATL11? Either way, I'm happy to help get you set up to contribute this directly to icepyx 😄

[s2002365]

Hi @weiji14 - sorry I missed this reply! I'm sure there are a number of use cases, but for my work I am mainly interested in looking at tracks that cross approx perpendicular to the grounding line. This means that often I only want either ascending or descending tracks as the one group may all be parallel to the GL, which I don't need (but currently still have to download if I select all tracks in a certain region). I mainly use ATL06 but would be useful to apply to ATL11 as well if possible! Thank you for offering to help with this, I am chatting to Jessica next week then will get in touch :) It will be my first time contributing to something like this so will be very grateful for any advice.

[weiji14]

Ah ok, so you'll want a filter to avoid downloading unnecessary data. Implementation-wise, I'm not sure if it's possible to modify icepyx.Query to tell NSIDC that we just want ascending/descending tracks (i.e. it might require coordinating with the data provider), but @JessicaS11 should have a better idea, or at least know who to talk to about this.

Will you be joining the icepyx meeting next Monday (see https://discourse.pangeo.io/t/icepyx-team-meetings/722/5)? I can join in then to chat about this, or we could set up a separate meeting earlier in the day for you.

[s2002365]

Ok yeah I thought it would probably be more complicated than it sounds... And thanks for pointing me to the meeting calendar, I will try join the meeting on Monday! See you there :)