# Presentation: 919455

## A North-American Disturbance Record from Landsat: Overview and Context 

**A North-American Disturbance Record from Landsat: Overview and Context**** **
**Dr. Jeffrey Masek, GSFC****Dr. Forrest Hall, GSFC/UMBC**
**Mr. Ed Masuoka, GSFC****Dr. Robert Wolfe GSFC/RSC****Dr. Nazmi Saleous GSFC/RSTX**

*GSFC Carbon Theme*

## Continuity Processing for Land

*Continuity processing seeks to meld diverse remote sensing sources into a coherent history of terrestrial dynamics... at both coarse and fine resolution *

## Fine-Resolution Stream

-  30+ year Landsat archive essential for assessing land-cover change, disturbance, and above-ground biomass at fine resolution over long periods of time
-  SDB/EarthSat GeoCover product provides a *geometrically* corrected archive
- 	- 1975, 1990, 2000 epochs
- 	- Orthorectified to map base
- 	- Mostly clear scenes, centered on peak-NDVI
- 	- 30-80 m spatial resolution
-  To be used for ESE analyses,  this archive must be calibrated, processed to surface reflectance and integrated with other satellite data
-  *There has never been a surface reflectance dataset created from Landsat archive*
* **There has never been an automated analysis effort to create continuity science products from the Landsat archive*

## Disturbance Fluxes from Landsat

-  Quantifying disturbance dynamics are essential for understanding continental  carbon budgets
-  Disturbance emits C to atmosphere
-  Regrowth following disturbance controls the forest age structure and net ecosystem exchange (NEE)

**Disturbance Fluxes from Landsat**

## Scaling Up 

- Disturbance   History

- Biomass

- Biophysics, Productivity

- Climate

- Ecosystem
- Productivity
- Models

- Atmospheric CO2 Fluxes
*(gridded, global, monthly)*

***Landsat***

***Inventories, Lidar, Radar***

***MODIS***

## Programmatic Context

- Carbon/Ecosystems
-        Roadmap

- North American
- Carbon Program

- ESE Science Questions

- ESE National Applications

-  Fine resolution record of
-  land-cover conversion
-  disturbance
-  recovery
-  biomass / biomass change
-  carbon consequences

## LEDAPS

- The Landsat Ecosystem Disturbance Analysis Adaptive Processing System (LEDAPS) will...
*Create decadal surface reflectance (SR) images from the North American Landsat GeoCover archive for the period 1975-2000*
*Analyze these SR images for forest disturbance, recovery, and conversion*
*Make SR and disturbance products available to the carbon science and Landsat applications communities*
*Work with remote sensing and carbon science communities to tailor processing to meet science needs*
*Work with representatives of USDA, USDA Forest Service, Canadian Forest Service to evaluate applications utility of SR image database.*

## Preprocessing

- 2000, 1990
- GeoCover TM/ETM+

- 1975
- GeoCover MSS

- Calibration
- Atm. Correction
- Cloud//Snow mask

**MODIS**
**Aerosols**

-  IT Normalization

**Radiometrically Consistent Surface Reflectance Dataset (1975-2000)**

- Other Landsat Data

-  Orthorectification
-  Precision Correction
-  Invariant Target
-   Normalization or  Atm. Correction

- Analysis

**QA/**
**Validation**

**Landsat Preprocessing and Analysis**

-  Disturbance Rate, Type
-  Land Cover Conversion Rate
-  Spectral Unmixing for Fractional Change

**Disturbance/Recovery **
**Products for Carbon Assessments**

- Aggregation

**Notes:**
To  render these data sets radiometrically compatible for highly automated analysis, we will begin with the most recent 2000 ETM+ data, which is calibrated, use MODIS estimates of aerosol concentrations to atmospherically correct the landsat scenes, in mountainous regions correct for terrain illumination effects, and cloud and snow mask the images.

The 1975 and 1990 era images would then be rendered radiometrically consistent with the 2000 era scenes, using one of a  number of existing algorithms to match digital count values between scenes of invariant bright and dark targets in the images -- a sort of vicarious calibration.

In some cases where we might need more than the one landsat scene in the EarthSat collection, we would also go into the EDC archive and match additional scenes.

Once we have three decades of radiometrically consistent scenes, all kind of possibilities open up for disturbance mapping.  For example, as s hown in this little diagram to the left here, and blown up in the next slide,.

## Proposed LEDAPS Project Elements

**Reflectance and Forest Disturbance algorithms / validation **

**Agricultural **
**soil carbon **
**dynamics**

- NAM Reflectance Product

- NAM Disturbance Product

- NAM Waveform Product

- MODAPS Hardware Upgrades

**SEEDS **
**Participation**

**Community Workshops**

**FIA Validation**

**Data and ****Product**
**Distribution**

**Proposed LEDAPS Project Elements**

**Data Processing**

***Science and applications***
*** ******community input***

***Regional, North American***
***Datasets***