Saturday, February 13, 2010

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 FileLevel 2A Brightness Temperature File
Output FileLevel 2 Land File
Data ProducedSoil Moisture, Vegetation Water Content, Land Surface Temperature, Surface Type
Uses PORT?Yes
PlatformLinux

L2_Rain
Input FileLevel 2A Brightness Temperature File
Output FileLevel 2 Rain File
Data ProducedRain Rate, Rain Type, Rain Status, Surface Type
Uses PORT?No
PlatformLinux

L2A
Input FileLevel 1A AMSR-E File
Output FileLevel 2A Brightness Temperature File
Data ProducedAMSR-E Scan Information
Uses PORT?No
PlatformWindows 2000/XP

L2B_Ocean
Input FileLevel 2A Brightness Temperature File
Output FileLevel 2B Ocean File
Data ProducedVery 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
PlatformLinux

L3 Land
Input File30 Days Of Level 2 Land Files
Output FileLevel 2B Ocean File
Data ProducedAMSR-E Frequency Scans, Soil Moisture, Vegetation Water Content, Land Surface Temperature
Uses PORT?No
PlatformLinux

L3 Ocean
Input FileLevel 2B Land Files (Days Worth, Weeks Worth, Month's Worth)
Output FileLevel 2B Ocean File
Data ProducedLow Resolution Sea Surface Temperature, Low Resolution Wind, Medium Resolution Wind, Medium Resolution Vapor, High Resolution Cloud
Uses PORT?No
PlatformLinux

L3 Rain
Input FileLevel 2A Brightness Temperature File (Month's Worth) Level 2B Rain Files (Month's Worth)
Output FileLevel 3 Rain File
Data ProducedLand Rain, Ocean Rain
Uses PORT?No
PlatformLinux

L3 Sea Ice
Input FileLevel 2A Brightness Temperature File (Day's Worth)
Output FileLevel 3 Sea Ice File
Data ProducedFrequency Scan Data, Ice Data, Snow Depth Data
Uses PORT?No
PlatformLinux

L3 Snow
Input FileLevel 2A Brightness Temperature File (Day's Worth), Level 3 Snow Files (5 Days Worth, Month's Worth)
Output FileLevel 3 Snow File (Daily, 5 Days, Monthly)
Data ProducedSnow Data
Uses PORT?No
PlatformLinux


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

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