# Presentation: 012317

## Landsat-5 TM and Landsat-7 ETM+ Performance Update

**LDCM Science Team Meeting**
**January 9, 2008**
- Brian Markham
**Landsat Calibration Scientist, NASA/GSFC  Landsat Project Science Office**
**Brian.L.Markham@nasa.gov**
**301-614-6608**

## Landsat Calibration Team

**Ron Hayes****2****,**** ****Julia Barsi****4****, Obaidul Haque****2 ****,**** ****Raj Rengarajan****2****, **
**Esad Micijevic****2****,  Rynn Lamb****2****, Mike Choate****2****, **
** ****Pat Scaramuzza****2****, Gyanesh Chander****2****, **
**John Schott****5****, Simon Hook****6****, Kurt Thome****7****, and teams**

**Landsat Calibration Team**

**1**** LPSO, NASA/GSFC, **
**2**** SAIC/EROS****
** ****3**** Image Processing Lab, South Dakota State University**
** ****4**** LPSO, SSAI/GSFC**
**5**** Center for Imaging Science, Rochester Institute of Technology**
**6 ****NASA/Jet Propulsion Lab**
**7**** Remote Sensing Group, University of Arizona**
**** Worked performed under ****U.S. Geological Survey contract 03CRCN0001**

## Landsat-7 ETM+ Geometric and Spatial Update

- Band-to-Band registration typically 0.05 pixels or better in line and scan direction (excluding band 6)
- MTF has stabilized in all bands model
- band 4 slightly below specification of 0.275
- Band 8 behavior consistent with pre-launch predictions
- Switch to bumper mode disrupted ETM+ sensor alignment calibration
- Degraded geodetic accuracy since April 1, 2007
- Pre-switch : 97% scenes better than 50 meters RMSE
- Post-switch: 65% scenes better than 50 meters RMSE

## Along-Scan MTF vs. Date

## ETM+ Bumper Mode Performance

- Bumper parameter trends have stabilized following a brief adjustment period in early April
- ETM+ bumper mode performance is monitored in the same way as L5 TM performance
- Analysis performed using daily calibration parameters
- Within-scan accuracy statistics for ETM+ SAM mode, L5 TM bumper mode, and ETM+ bumper mode:

|  | FWD Line RMSE | FWD Samp RMSE | REV Line RMSE | REV Samp RMSE |
| --- | --- | --- | --- | --- |
| ETM+ SAM Mode | 4.3 m | 4.0 m | 4.0 m | 3.9 m |
| L5 TM Predicted
ETM+ Predicted | 5.4 m
5.3 m | 7.6 m
6.5 m | 5.4 m
5.3 m | 7.0 m
6.4 m |
| L5 TM Refined
ETM+ Refined | 5.4 m
5.3 m | 5.6 m
5.5 m | 5.4 m
5.3 m | 6.2 m
5.4 m |

## Landsat-5 TM Geometry Update

- Landsat-5 TM operating in bumper mode since 2002
- Generate both monthly (heritage) and daily bumper mode parameter sets for L5
- Bumper mode calibration will likely require immediate update and (initially) frequent refinement if / when Landsat 5 resumes imaging operations

## Bumper Mode Performance Summary

- Summary within-scan accuracy statistics are presented below for both the predicted and refined calibration parameters
- Lifetime and recent statistics are shown
- ETM+ SAM mode values are shown for comparison

|  | FWD Line RMSE | FWD Samp RMSE | REV Line RMSE | REV Samp RMSE |
| --- | --- | --- | --- | --- |
| ETM+ SAM Mode | 4.3 m | 4.0 m | 4.0 m | 3.9 m |
| TM Bumper Mode
(Predicted) Life
Since 01APR2007 | 
5.5 m
5.4 m | 
7.9 m
7.6 m  | 
5.6 m
5.4 m | 
7.9 m
7.0 m |
| TM Bumper Mode
(Refined) Life
Since 01APR2007 | 
5.5 m
5.4 m | 
6.4 m
5.6 m | 
5.6 m
5.4 m | 
6.7 m
6.2 m |

## Landsat-7 ETM+ Reflective Band Radiometry Update

- Relative detector-to-detector normalization, i.e., striping less than ± 0.1%
- Between-date detector gain stable to < 0.5%/year
- Based on desert sites--generally not statistically significant
- Absolute radiometric accuracy better than ± 5%
- Noise stable over mission life
- Small improvement with SLC-off
- Anomalous coherent noise gone with SLC-off
- SLC failure had no significant impact on L7 ETM+ reflective band radiometry- continues to be excellent

## Slide 9

## Landsat-7 ETM+ Thermal Band Radiometry Update

- Relative detector-to-detector normalization, i.e., striping less than ± 0.1%
- No observable change in instrument responsivity
- Absolute radiometric accuracy better than 1K
- Noise stable over mission life
- Switch to bumper mode resulted in change in shutter bias extraction regions
- Incorrect shutter region windows as well as pulse losses resulted in severe banding (low gain) and striping (high gain) in data acquired and processed between April 1 and July1 and October 1 and October 28

## BLUE/GREEN: JPL data                PINK/BROWN: RIT data

- remaining RMS
- 0.1 W/m2/sr/m or 0.7 K

- “reanalysis data” incorporated

## I2596

- B62 - processed with Oct 1 CPF

- B61 - processed with Oct 1 CPF

## I2607

- B61 - processed with modified CPF, new bias_locations and ACCA biases

- B62 - processed with modified CPF, new bias_locations and ACCA biases

- Still can’t compute gain for D3,5,7,8

## Landsat-5 TM Reflective Band Radiometry Update

- Within-band within-scene internal stability
- Scan-Correlated Shift (SCS) of up to 0.7 DN
- Correctable with scan line-by-scan line background subtraction
- Memory Effect of up to 4 DN
- Currently corrected in NLAPS processing
- Some banding and striping issues remain to be resolved
- Between-date stability
- Interference cycling from icing on B5 and B7
- Correctable with IC processing or LUT that includes interference cycling
- Radiometric calibration processing
- Uses Gain Calibration History stored in Look-Up Table
- Extracts and applies biases on a scan line by scan line basis
- Rescaled to Fixed Radiance Range (LMIN, LMAX)
- Look-up Table revised April 2, 2007 to reflect revised trends from Sahara desert site data obtained from ESA

## Slide 15

**Notes:**
Band 2, pink curve anchored to L5 absolute gain from 1999 ETM+ cross call;  2004-2005 cal as determined by UAZ.
Note excellent agreement with 1999 cross cal point: 0.4%
Precision in UAZ cal point ~1.5%
Precision in 1999 cross-cal point based on Teillet paper is also around 1.5%
Again, two independent calibration agree very well.
Same comments regarding first two years of life—IC data of questionable use, initial DS data points may suggest steeper decay (Helder’s hypothesis, no on else agrees with!)

## Landsat-5 TM Thermal Band Radiometric  Calibration Update

- Sensitivity reduced by up to 50% by icing build-up on cold focal plane window
- Correctable with Internal Calibrator
- Bias adjustment of 0.092 W/m2 sr m effective 02-Apr-07
- Only for data acquired since April 1999 (ETM+ era)
- Recommended users with data add 0.092 to their pre-02-Apr-07 processed radiance level products
- Pre-1999 era data under evaluation by RIT using Great Lakes buoys
- Radiometric Calibration on Scene-by-Scene Basis using the response to the Internal Calibrator
- Rescaled to Fixed Radiance Range (LMIN, LMAX)
- Absolute accuracy ±1%

## L5, L7 Delta-L comparison

## Summary

- Landsat-7 ETM+ performance stable, except for changes induced by switch to bumper mode
- Landsat-5 TM performance stable through October
- Restart of imaging expected to require frequent bumper mode calibration
- Landsat-5 TM reflective and thermal band calibrations updated 02 April 2007
- Thermal band calibration accuracy since 1999 now comparable to ETM+ thermal band