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MODIS/Aqua CLD Mask Spect. Results 250m and 1km 5-Min L2 Wide Swath Subset along CloudSat V002 (MAC35S1) at GES DISC

Metadata Updated: December 7, 2023

This is the wide-swath MODIS/Aqua subset along CloudSat field of view track. The goal of the wide-swath subset is to select and return MODIS data that are within +-100 km across the CloudSat track. I.e. the resultant MODIS subset swath is sought to be about 200 km cross-track. Geolocations in the original product, however, are subsampled at 5-km, and thus the crosss-track width of the subset geolocations is 41 pixels. The subset Cloud Mask has 201 pixels across-track. However, some of the Cloud Mask information is at bit level, thus allowing storing actually 250-m information in seemingly 1-km pixels. This is achieved by reserving 2 bytes (the last two out of six) of every 1-km pixel as 16 yes/no-cloud bits. Each one of these 16 bits flags a corresponding 250-m tile inside the 1-km pixel. Their state is described in the local attributes to the Cloud_Mask HDF data set, and accordingly must be interprated as 0=YES, 1=NO. Thus the effective cross-track width, for these two bytes only, is 804 tiles of 250-m denomination.

Along-track, all MODIS pixels from the original product are preserved.

In the standard product, the MODIS level-2 cloud mask product is a global product generated for both daytime & nighttime conditions at 1-km spatial resolution (at nadir) and for daytime at 250-m resolution. The algorithm employs a series of visible and infrared threshold and consistency tests to specify confidence levels that an unobstructed view of the Earth's surface is observed. An indication of shadows affecting the scene is also provided. The 250-m cloud mask flags are based on the visible channel data only. Radiometrically accurate radiances are required, so holes in the cloud mask will appear wherever the input radiances are incomplete or of poor quality. The shortname for this Level-2 MODIS cloud mask product is MYD35_L2 and the principal investigator for this product is MODIS scientist Dr. Paul Menzel (

(The shortname for this product is MAC35S1).

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Created Date November 12, 2020
Metadata Updated Date December 7, 2023

Metadata Source

Harvested from NASA Data.json

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Additional Metadata

Resource Type Dataset
Metadata Created Date November 12, 2020
Metadata Updated Date December 7, 2023
Identifier C1236350936-GES_DISC
Data First Published 2006-06-02
Language en-US
Data Last Modified 2018-03-01
Category ATDD, geospatial
Public Access Level public
Bureau Code 026:00
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Citation MODIS Science Team. GES DISC. 2006-10-01. MAC35S1. Version 002. MODIS/Aqua CLD Mask Spect. Results 250m and 1km 5-Min L2 Wide Swath Subset along CloudSat. Greenbelt, MD, USA. MAC35S1. Archived by National Aeronautics and Space Administration, U.S. Government, Goddard Earth Sciences Data and Information Services Center (GES DISC). Digital Science Data.
Creator MODIS Science Team
Data Presentation Form Digital Science Data
Graphic Preview File
Harvest Object Id 06b105b9-77f9-4511-8361-3f15654ef771
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Issue Identification MAC35S1
Homepage URL
Metadata Type geospatial
Old Spatial -180.0 -90.0 180.0 90.0
Program Code 026:001
Release Place Greenbelt, MD, USA
Series Name MAC35S1
Source Datajson Identifier True
Source Hash bcaba8b376b031bda7eefdb19d1b96dc4ab7d62101eb6956867c08168085ac89
Source Schema Version 1.1
Temporal 2006-06-02T00:00:00Z/2018-03-01T23:59:59.999Z

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