Most MODIS Science Data Set (SDS) layers are in 8-bit or 16-bit format. This requires a scaling factor to be applied. For information on the scale factor of a specific band for a specific product, please see the corresponding DOI landing. DOI landing pages can be access via the MODIS Products Table. More information on the scaling factor is available by watching the Part 2s of the MODIS Version 6 Data at NASA's LP DAAC videos on YouTube.
How can I interpret the MODIS Quality data layers?
The majority of the MODIS land products contain quality layers. Each layer contains a lot of information about the quality information associated with each individual pixel in the scene. To aid in file size management, this data has been packed in bit format. The LP DAAC offers several tools to aid in unpacking the bits and interpreting the quality information. The Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) allows users to view and interact with quality information for a variety of products before they download the data. The ArcGIS MODIS Python Toolbox provides users with a simple and intuitive way to decode and interact with quality layers for previously downloaded MODIS products using ArcGIS. More information on interpreting the quality information and using these tools is available by watching the Part 3s of the MODIS Version 6 Data at NASA's LP DAAC on videos YouTube.
What improvements have been implemented in MODIS V6.1?
The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes.
Changes include:
- The response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS.
- Corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands.
- Corrections have been made to the Terra MODIS forward look-up table (LUT) to include an update for the period 2012 - 2017.
- A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).
Why are there data gaps for MODIS acquisitions after July 7, 2023?
Data gaps or missing data have become more of a routine occurrence for Terra, Aqua, and Terra+Aqua Combined MODIS data products. On July 7, 2023, the MODIS Flight Operations Team transitioned to a new schedule and no longer attempts to recover Level 0 data if the missed contact happens after regular business hours. Once data gaps that have occurred during the Light-Out-Operations (LOOps) period from 6 pm to 6 am Eastern time have been confirmed, the data loss events will be added to the list of dates and times of the known LOOps events.
All Terra, Aqua, and Combined Terra+Aqua MODIS Version 6.1 data products are directly impacted by the non-recoverable data loss.