Getting Started with MODIS V6 Surface Reflectance Data Part 2

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Getting Started with MODIS Version 6 Surface Reflectance Data Part 2: Using the Data This video focuses on the National Aeronautics and Space Administration’s (NASA) Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Version 6 Surface Reflectance data distributed by NASA’s Land Processes Distributed Active Archive Center (LP DAAC). Information about the definition of “Surface Reflectance”, the MODIS Surface Reflectance data products, the scale factor of the data and other data values will be provided in this video. The video will also explore various MODIS band combinations that are beneficial for a variety of science applications. To learn more about on MODIS Version 6 Surface Reflectance data and other data products distributed by the LP DAAC please visit https://lpdaac.usgs.gov/. The LP DAAC is one of twelve NASA Earth Observing System Data and Information System (EOSDIS) DAACs. It is located at the United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota. The LP DAAC ingests, archives, processes and distributes NASA Earth science land processes data and information. 

Details

Image Dimensions: 1280 x 720

Date Taken:

Length: 00:05:42

Location Taken: Sioux Falls, SD, US

Video Credits

Script and content created by Danielle Golon, Innovate, Inc.!, contractor to USGS EROS for the NASA LP DAAC.

Transcript

Getting Started with MODIS
Version 6 Surface Reflectance

Data Part 2: Using the Data.
Presented by the Land Processes

Distributed Active Archive
Center or LP DAAC. This is

part 2 of the “Getting Started
with MODIS Version 6 Surface

Reflectance Data” video series.
This video will cover what

“Surface Reflectance” means,
Aqua and Terra MODIS surface

the scale factor of the data

and other data values, and
various MODIS band combinations.

Surface reflectance is the
amount of light reflected by

the surface of the Earth.
MODIS surface reflectance data

products provide an estimate of
the surface spectral reflectance

from the ground, with
atmospheric correction.

Surface reflectance is a unit
less ratio of surface radiance

to surface irradiance with a
value that typically falls  

between 0.0 and 1.0. MODIS
Version 6 Surface Reflectance

products are distributed as
Hierarchical Data Format –

or HDF files. The HDF files
contain all the science datasets

or SDS for the MODIS data
product. The Digital Object

Identifier or DOI Landing Page
for each MODIS Version 6 Surface

Reflectance product lists all
of these science datasets under

the Data Layer Characteristics
table. The science datasets will

differ between the MODIS Version
6 Surface Reflectance products.

However, most MODIS Version 6
Surface Reflectance products

will contain seven surface
reflectance bands.

The seven MODIS surface
reflectance bands have a

spectral range from 459 to
2155 nanometers. Here is a

visual representation of the
science datasets stored within

a MOD09A1 HDF file. MOD09A1 is
the Terra MODIS Version 6 8-Day

Surface Reflectance 500 m
level 3 gridded product.

The HDF file for this product
contains 7 surface reflectance

bands, quality information,
information about angles of

the sun and satellite, and the
day of the year.

If your research involves
calculations of MODIS Version

6 Surface Reflectance data,
it is important to know that a

scale factor must be applied to
the data before you complete

your calculations or work with
the data. For MODIS Version 6

surface reflectance products a
scale factor of 0.0001 should be

applied to the seven surface
reflectance bands, resulting in

data values typically between 0
and 1. Data values that fall

outside this range are considered
fill values. The other science

dataset in the HDF file have
either a scaling factor of 0.01

or do not have a scaling factor.
Users can apply a scale factor to

their data via a data script recipe,
through manual calculation,

or in a geographic information
system (GIS) program.

To learn more about specific
scale factor, fill values,

and valid ranges for the
various MODIS Version 6

Surface Reflectance products
please see the DOI Landing

Pages on the LP DAAC’s
website at lpdaac.usgs.gov.

Stacking the surface reflectance
bands in different combinations

can emphasize different aspects
of the Earth’s surface.

Today we will demonstrate three
band combinations using the

MOD09A1 product. Band stacking
can be done using several programs.

Today we will show you how to stack
bands using Multispec, a free program

that allows users to interactive with
and analyze remote sensing data.

The band combination 1-4-3 creates
a true color image and is a

representation of how the human eye
would see the area.

Here is a view of part of Europe
using the 1-4-3 band combination.

Vegetation is shown as green,
the snow in the Alps is white,

and the barren areas are tan
or brown.

Another band combination is 3-6-7,
which highlights snow and ice.

Here is the same location shown
using the 3-6-7 band combination.

In this band combination the snow
in the Alps is shown as red,

ice in clouds as light pink,
clouds are white, water is shown

as a dark red, vegetation is green,
and deserts are a light blue-green color.

The third band combination, 7-2-1,
is used to observe burn scars on

the Earth’s surface from fires.
This band combination is especially

useful in areas that have a lot of
wildfires throughout the year.

For example, the Western United States,
shown here, had a lot of fires in 2016.

Using the 7-2-1 band combination we
can see some of the burn scars

from these fires. Here is the same
Terra MODIS image enlarged and

reprojected to Universal Transverse
Mercator (UTM) for a better view of

the burn scars in California.
In the 7-2-1 band combination burn

scars are shown as red to
reddish-brown, vegetation is green,

desert or other naturally bare soil
is a pink, and water is black or

dark blue. For examples of how MODIS
Surface Reflectance products can be

used in scientific applications,
visit the LP DAAC website.

The Publications has relevant
literature, the Data in Action

section has short stories about
scientific applications, and the

E-Learning page has tutorials,
presentations, and other product

resources. Thank you for watching
our videos. For more information

on MODIS Version 6 Surface Reflectance
data please visit the LP DAAC

website at lpdaac.usgs.gov.