Hi there-
   I was wondering why there is the occasional appearance of more than one OC and SST file per day.  I'd assume that if I am only using L2 modis aqua, that I would only have one OC and one SST file for the daytime.  I find that I will often get something such as:

A2007018172000.L2_LAC_OC.x.hdf
A2007018172000.L2_LAC_SST.x.hdf
and
A2007018190000.L2_LAC_OC.x.hdf
A2007018190000.L2_LAC_SST.x.hdf

thanks!

Erin

Hi Erin,

The two scenes you mention overlap just a little (see
the attached image).  As one moves closer to the poles
the inter-orbit overlaps increase.

Regards,
Norman

Dear norman,
i have a similar thing as that, but the files i downloaded from modis lac level2 browser(by order) interface were 4 files in one day(only Rrs)
A2003001030500.L2_LAC_OC.x.hdf
A2003001031000.L2_LAC_OC.x.hdf
A2003001044000.L2_LAC_OC.x.hdf
A2003001044500.L2_LAC_OC.x.hdf
and seawifs mlac level2, there were 2 files in one day(only Rrs)
S2003001050650.L2_MLAC_OC.x.hdf
S2003001032802.L2_MLAC_OC.x.hdf
these files were not same overlaping as you mentioned above, and is there miss for me?
also i have fixed the long. and lat. before downloading data, but these files showed the range variat with each other, how to fixed the specific the range as i expected?
do i need  composite command to do this?
if i want to compare seawifs one day with modis same day value, how to deal with files, i also check there are two ways to do this, one way is to processing data to Level 3, creating daily composites, for this way, i know l2bin to process from seadas command help, but is there some script for these processing? another way is to composite command to output one day image as here suggested
(http://oceancolor.gsfc.nasa.gov/forum/oceancolor/topic_show.pl?pid=15547;hl=modis%20l2bin%20script#pid15547), i am still not clear about it, would someone give more details about it?
modis daily image,mean image and composite image were listed, while mean image displayed no value,is there some miss of my picture?
thanks

Yongjiu,

It is quite possible that all of the scenes you mention
get selected by one search since they are all in the
same general western Pacific/eastern Asia region.
I assume that your specified area of interest was larger
that a single click on the map.

Not being a SeaDAS expert myself, I will leave the rest
of your query to our SeaDAS team.

Regards,
Norman

Dear Norman,

Thanks for reply.
I am not so clear about the meaning of the search you mentioned, sorry! Is that pathway from north to south? I just get the modis l2 lac datasets through leve 1 and 2 data browser interface, and ordered by mail. Also, I fixed the  longitude and latitude in the swath box. and selected only Rrs in level 2 list. 
The original file in one day like 2003 day1, there are 4files, with first 2 files no data, and latter two showed not the fixed position i set, some area beyond my region northmost, some was not.
So, maybe it's better to composite this two? or these four? or even average these value in each pixel? what's the difference?

Regards,
joe

Hi Joe,

You can specify your region by bounding latitudes and
longitudes, by a radius around your click, or by predefined
regions.  Please see the help page at
http://oceancolor.gsfc.nasa.gov/BROWSE_HELP/top_level.html .

I note that several of your search results are pretty
cloudy.

http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=A2003001030500.L2_LAC
http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=A2003001031000.L2_LAC
http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=A2003001044000.L2_LAC
http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=A2003001044500.L2_LAC
http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=S2003001050650.L2_MLAC
http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?file=S2003001032802.L2_MLAC

Perhaps this accounts for your poor coverage?

Norman

thanks.
i got it.