First Look At NSIDC Source Code

In this post we'll take a look at how to order source code from the National Snow and Ice Data Center and what that source code does.

Ordering The Source Code
The source code is stored in 9 folders that NSIDC calls Delivered Algorithm Packages (DAPs). You must order the source code before you download it. This is done by sending off a request to their User Services department using this form. Just tell them you'd like to download the DAPs and they will give you instructions on how to register and download the DAPS via FTP.

Some of the DAPS also use the PORT Mathematical Subroutine Library.

The Code
The code you'll get is written in Fortran and C. There are also data files required by each DAP. Each DAP comes in its own folder and each folder contains a zip file of the source and data files, as well as some read-me files. After you unzip the files, you'll find the source code in the src folder and the data files in the anc folder.

To finish out this post, we'll take a quick look at each DAP.

L2_Land

Input File	Level 2A Brightness Temperature File
Output File	Level 2 Land File
Data Produced	Soil Moisture, Vegetation Water Content, Land Surface Temperature, Surface Type
Uses PORT?	Yes
Platform	Linux

L2_Rain

Input File	Level 2A Brightness Temperature File
Output File	Level 2 Rain File
Data Produced	Rain Rate, Rain Type, Rain Status, Surface Type
Uses PORT?	No
Platform	Linux

L2A

Input File	Level 1A AMSR-E File
Output File	Level 2A Brightness Temperature File
Data Produced	AMSR-E Scan Information
Uses PORT?	No
Platform	Windows 2000/XP

L2B_Ocean

Input File	Level 2A Brightness Temperature File
Output File	Level 2B Ocean File
Data Produced	Very Low Resolution Sea Surface Temperature, Low Resolution Sea Surface Temperature, Low Resolution Wind, Medium Resolution Wind, Medium Resolution Vapor, High Resolution Cloud
Uses PORT?	No
Platform	Linux

L3 Land

Input File	30 Days Of Level 2 Land Files
Output File	Level 2B Ocean File
Data Produced	AMSR-E Frequency Scans, Soil Moisture, Vegetation Water Content, Land Surface Temperature
Uses PORT?	No
Platform	Linux

L3 Ocean

Input File	Level 2B Land Files (Days Worth, Weeks Worth, Month's Worth)
Output File	Level 2B Ocean File
Data Produced	Low Resolution Sea Surface Temperature, Low Resolution Wind, Medium Resolution Wind, Medium Resolution Vapor, High Resolution Cloud
Uses PORT?	No
Platform	Linux

L3 Rain

Input File	Level 2A Brightness Temperature File (Month's Worth) Level 2B Rain Files (Month's Worth)
Output File	Level 3 Rain File
Data Produced	Land Rain, Ocean Rain
Uses PORT?	No
Platform	Linux

L3 Sea Ice

Input File	Level 2A Brightness Temperature File (Day's Worth)
Output File	Level 3 Sea Ice File
Data Produced	Frequency Scan Data, Ice Data, Snow Depth Data
Uses PORT?	No
Platform	Linux

L3 Snow

Input File	Level 2A Brightness Temperature File (Day's Worth), Level 3 Snow Files (5 Days Worth, Month's Worth)
Output File	Level 3 Snow File (Daily, 5 Days, Monthly)
Data Produced	Snow Data
Uses PORT?	No
Platform	Linux

References:
National Snow And Ice Data Center User Services Contact Form
PORT Mathematical Subroutine Library