Directory Naming Conventions

Data Locations and Naming Conventions The following was written following the Surf Zone Optics experiments in 2010 at the FRF. It contains most of the useful file naming conventions.

Data are stored both at the CIL and at the FRF. I’m unclear how the FRF storage works but will describe the CIL strategy.

Data are stored on the CIL ftp site, cil-ftp.coas.oregonstate.edu and can be downloaded using normal anonymous ftp (with a valid RFC822 format email address as the password). Duck data is sorted by site/year/camera/day/file. For example, images for C2 of March 2, 2015 would be located in /ftp/pub/argus02b/2015/c2/062_Mar.02.

Argus filenames using a long (and useful) naming convention. For example: 1425294001.Mon.Mar.02_11_00_01.GMT.2015.argus02b.c1.timex.jpg is a time exposure images for C1 collected on March 2, 2015 at 11:00:01 GMT. All Argus data are saved in GMT (because we have stations in many time zones). Note that images also have timestamp and other information imprinted on the top and bottom borders. These are written in local standard time (note that merged images stored as camera “Cx” are only listed in GMT time – more on Cx below). Be careful to not confuse these (image stamp in EST, filename in GMT = EST+5). Our primary time reference is epoch time, a computer standard that is the number of seconds since January 1, 1970 (GMT). This is the 10-digit leading number in the filename. Routines to convert between epoch to matlab’s datenum are located in /ftp/pub/Experiments/SZO2010/commonMatlabCode.

Six types of images are collected: • Snapshot • Timex – average of 2Hz frames collected over ten-minute period • Var – standard deviation of same image sample • Bright – brightest that each pixel gets over the same period • Dark - darkest that each pixel gets over the same period • Rundark - darkest computing using a running average algorithm to suppress noise In addition, daytimex images average all of the timex images for a day.

Merged images like Figure 1, are automatically processed and are stored as camera Cx using the same naming conventions but with an additional suffix ‘merge’. For example, 1432908003.Fri.May.29_14_00_03.GMT.2015.argus02b.cx.bright.merge.png is a merged brightest image from May 29 at 14:00:-3 GMT (~0900 EST or 1000 EDT). These are stored as png images. Note that the merged image data are also stored as .mat files so you can create your own figures, for example using ‘imagesc(y,x,I)’.

{The current format may be ‘imagesc(XYZ(:,1), XYZ(:,2), RAW)}

Figure 1. Merged snapshot showing the fields of view of the six primary cameras installed during the upgrade to argus02b in 2015.