MODIS cloud free land

Images made by compositing MODIS MOD09A1 surface reflectance product images

May 2001

These MODIS images were created by finding the median value over several to many MODIS MOD09A1 surface reflectance images for any pixel. The MODIS MOD09A1 surface reflectance is an 8 day minimal-cloud composite of surface reflectance; however depending on the location and time of year there can still be quite a few clouds and cloud shadows in any particular 8 day composite. The MODIS MOD09A1 includes a cloud pixel mask and a cloud shadow mask, but the first version of DAAC software creating the MOD09A1 tiles, the masks do not identify all pixels that look cloudy or shadowed. I wrote an IDL program to make these cloud-free images since I needed MODIS images with no clouds or cloud shadows.

The ocean and other large water areas in these images are made up since the MODIS MOD09A1 product is a land reflectance product, but the near-shore waters are real data.

Himalayas

The first scene I created is a view of the Himalayas. This image was assembled from about 24 ISINUS tiles and composited from about 10 different times from 2000161 to 2000313. Several of the MODIS scientists have pointed out that compositing over such a large time range essentially removes any seasonal variation from the image, making it less interesting. This image was created for a flyover of the Himalaya range.

medium jpg,	2700x1800,	5.2 MB
very large tiff,	10800x7200,	128 MB

Florida

The next scene is of Florida, Cuba and the Bahamas. This scene is composited from 5 8-day composites from 2000361 to 2001025. It should be a nice winter season image, but right now it is stretched to over-emphasize the green channel since I needed it for an animation using GOES-9 data from July. There's a link to the original 16 bit data below which could be used to make a more seasonally appropriate image, but the 16 bit image does have several problem areas near the eastern Florida coastline and Bahamas that need to be cleaned up by hand.

Large jpeg,	3100x3500,	1.1 MB
Large tiff,	3100x3500,	15.1 MB
Large 16bit tiff,	3100x3500,	65.2 MB