Mapping the Path to Digital Sensor Calibration

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U.S. Department of the Interior

U.S. Geological Survey

National Center for EROS

Remote Sensing Technologies Group

Mapping the Path toDigital Sensor Calibration

Mapping the Path toDigital Sensor Calibration

USGS Land Remote Sensing ProgramASPRS Camera Calibration Session

March 9, 2005

Greg StensaasUSGS NC EROS

[email protected]

Greg StensaasUSGS NC EROS

[email protected]

Phil RufeUSGS MCMC

[email protected]

Phil RufeUSGS MCMC

[email protected]

George LeeUSGS WRG

[email protected]

George LeeUSGS WRG

[email protected]

Jon ChristophersonUSGS NC EROS/SAIC

[email protected]

Jon ChristophersonUSGS NC EROS/SAIC

[email protected]

2U.S. Department of the InteriorU.S. Geological Survey

HistoryHistory

USGS has been calibrating aerial film cameras since 1973USGS actively involved with establishing requirements and standards for photo imagery for many years

Film camera standards since 1950’s with the National Bureau of StandardsNational Map Accuracy standards since the 1940’s

In 1999 ASPRS panel asked USGS to develop standards, policies and guidelines for the digital aerial mapping communityUSGS Land Remote Sensing Program has a cross center project team actively working to answer ASPRS recommendations


ASPRS RecommendationsASPRS Recommendations

1. The USGS Optical Science Laboratory (OSL) should continue to calibrate film mapping cameras using the present calibrator and the Simultaneous Multiframe Analytical Calibration (SMAC) program.

2. Initiate the design, development, and implementation of a digital camera calibration capability at the USGS (est. required investment - $4 M).

3. Conduct research efforts in order to support a reliable and cost effective transition to digital acquisition systems (est. required investment - $1 M)

4. Initiate the design, development and implementation of an in situ (flight) calibration process.

5. A calibration/verification process must be established for satellite imagery.

6. Develop a U.S. Standard for camera and sensor calibration. 7. Adequate funding should be sought in order to ensure the continued

operation of the Optical Science Laboratory (OSL), as well as to provide for the improvements and extensions described in the preceding recommendations.


The USGS Responds…..The USGS Responds…..


One: Continue Operating OSLOne: Continue Operating OSL

1. “The USGS Optical Science Laboratory (OSL) should continue to calibrate film mapping cameras using the present calibrator and the Simultaneous Multiframe Analytical Calibration (SMAC) program.”

Ongoing todayUSGS has invested in upgrades and continues to do soHardware upgrades, electronics, software

USGS in year-long search for glass platesFinally identifying plates that will workInvested in multi-year glass plate supplyContinuing to investigate film and electronic alternatives

The USGS is committed to continuing OSL operations for foreseeable future


Two & Three: Research/Build Digital CapabilitiesTwo & Three: Research/Build Digital Capabilities

2. “Initiate the design, development, and implementation of a digital camera calibration capability at the USGS (estimated required investment - $4 M).”

3. “Conduct research efforts in order to support a reliable and cost effective transition to digital acquisition systems (estimated required investment - $1 M)”

USGS has already invested in the following research capabilities

Pictometry for Small/Medium-Format calibration cageOSU for In-Situ methodology for digital (and potentially film?)SDSU-developed MTF tools; lab & in-situ

Requesting funding for additional capabilitiesFurther develop & validate in-situBuild & expand USGS sensor laboratory at EDCFurther work on MTF tool

(see more in Recommended Plans)


Four: In-Situ CalibrationFour: In-Situ Calibration

4. “Initiate the design, development and implementation of an in situ (flight) calibration process.”

USGS working with OSU, SDSU, industry, manufacturers to test and validate several different methodsDeveloped in-situ ranges for independent validation

Incorporates EROS instrumentation capabilities

USGS actively involved with industry and NASA SSC in Digital Airborne Product Verification (see Phil Rufe’s presentation)Digital Sensor manufacturers working this alsoVery promising!


Five: Satellite Data Five: Satellite Data

5. “A calibration/verification process must be established for satellite imagery.”

USGS, partnered with NASA and NGA, leading the Joint Agency Commercial Imagery Evaluation (JACIE) team.

On-going for four years now

Hosted at USGS Headquarters in Reston

JACIE evolving to address airborne and international datasets

USGS leading CRSSP implementation

USGS also involved in other Satellite Cal/ValLandsat(s) 5 & 7, EO-1 ALI and Hyperion, LDCM

Active in CEOS WGCV, EuroSDR, ASPRS/ISPRS

RObotic Lunar Observatory (ROLO)


Six: Develop StandardsSix: Develop Standards

6. Develop a U.S. Standard for camera and sensor calibration.

USGS has had standards for other data for yearsExisting National Map Accuracy Standards served paper maps for decadesDOQ standards served initial digitized aerial imageryThe limited capabilities of the sensors and processes originally used in producing digital orthoimagery led to simpler standards (primarily geometry)

The USGS will lead an effort to define new Digital Remote Sensing Data Standards

Desire ASPRS and industry participationPossibility for international standards w/ ISPRS

Data Standards Activity can begin as soon as possible!


Seven: USGS FundingSeven: USGS Funding

7. Adequate funding should be sought in order to ensure the continued operation of the Optical Science Laboratory (OSL), as well as to provide for the improvements and extensions described in the preceding recommendations.

OSL calibrations are paid by fees charged to camera owners

Fees likely to increase in FY06

This will be first fee increase since 1999

USGS Funding has been limitedHas limited work on digital and other areas

Project is established and ready for growth Optimistic for future


Digital Aerial Camera ObservationsDigital Aerial Camera Observations

There are:

Many classes of cameras/systems

Many potential users & uses of data

Growth of Digital Aerial Sensors has skyrocketed

Many attempting to exploit this new technology

Digital aerial is waiting to “take off”

Some digital systems equal the geometric performance of traditional film cameras

Tend to be the more expensive systems; cheaper systems may be capable in future

These capabilities were not even available in 1999!

Some manufacturers have good calibration in place already

Digital can offer benefits not found in film

Many more benefits possible; need applications development


The Problem with Digital CamerasThe Problem with Digital Cameras

Digital offers amazing possibilities to aerial mapping – very promisingDigital technology is evolving at incredible pace

Technologies are very diverse: pushbroom, staring array, multispectral, multi-sensor, etc.

Many Different Technologies all feed into digital imagingSensor, Inertial Measurement Unit, GPS, processing tools

The USGS believes it is impossible to cover all of these technologies and capabilities with one single “umbrella” camera calibration standard

So where do we go?


The Future: The Proposed USGS Plan for

Digital Data Quality Assurance

The Future: The Proposed USGS Plan for

Digital Data Quality Assurance


The USGS Proposed PlanThe USGS Proposed Plan

Focused on Sensors

Focused on Processes

Focused on the End Products


Focus on SensorsFocus on Sensors

Focus on Sensors - “Sensor Systems”Without sensors there are no processes or productsIncreasing capabilities and complexities will bring challenges

The USGS will offer “Type Certification” of digital systems

Certification includes not only sensors and associated systems, but also the entire “chain”

USGS will work with manufacturers & developers to certify chain(s)

e.g. Leica ADS-40 with ADS40-specific calibration technique(s), ADS40 processing software, etc.


Focus on ProcessesFocus on Processes

Focus on ProcessesAll products are the result of processes

The quality of aerial mapping imagery is at least as dependent on the processes as on sensors

Process control at least as important to customers as sensors

Processes make/break the quality chain

Quality demands that processes are controlled – and documented


Focus on Processes (cont.)Focus on Processes (cont.)

Processes include:Which sensors/systems – configuration controlMaintenance of sensor/systemsCalibration procedures, historyData handling, particularly steps where data is manipulatedProcessing software versions, etc.Any other external inputs

All of this information must be documented, ideally in the metadata associated with the final product


Focus on the End ProductsFocus on the End Products

The ultimate goal is to assure the quality of the final productPrevious work with Film Cameras was only with sensors: Camera CalibrationNational Map Accuracy Standards focused on end productsWork in between governed only by professionalism and dedication

And ground control Digital world has many different processes!


“Classes” of Digital Data“Classes” of Digital Data

Industry needs “Classes” of Digital ProductsApplies to those generating, processing, selling, buying and working with these dataCan apply to aerial, satellite, even lead to standards for non-imaging products, i.e. LIDAR.

Will develop different quality “classes” of digital mapping data

Based on resolution & accuracyInitial Classes for geometric and spatial qualityFollowed soon (?) by radiometric quality

USGS offers to lead standards development, with ASPRS/ISPRS


Examples of Data ClassesExamples of Data Classes

The following are notional examples to illustrate what data classes could be:

Class 0: No geometric/geodetic accuracy implied, “Pretty pictures”Class A: Ground Sample Distance (GSD) > 1.0 meter, geometric accuracies <0.5pixel sizeClass B: Ground Sample Distance (GSD) < 1.0 meter, geometric accuracies <0.4mClass C: GSD < 0.5m, geometric/geodetic <0.2mClass D: GSD < than 0.15m, geometric/geodetic <0.1mClass E: (Reserved for future capabilities)


What This All MeansWhat This All Means

USGS to work with sensor/system manufacturers Proving sensor capabilities and “calibrate-ability” now falls on manufacturers

Hardware/Software Certification burden is transferred from many individual flyers to (relatively) few manufacturers

Allows more in-depth understanding of each system, working directly with technologistsHelps keep burden of hardware/software performance on those who developed it

USGS to work with ASPRS to promote education of new standards for use by consumers


What This All Means (cont.)What This All Means (cont.)

Consumers benefit by clearer, defined choices for data

Easier procurement/contracting

Burden on flyers/producers now shifted to processes

Insists that defined processes be carried out and documentedAids in troubleshooting, maintaining high standardsFlyers are/should be doing this anyway

USGS Certification means more: A Greater Assurance of Data Quality!


Work Needed to be DoneWork Needed to be Done

USGS to establish contacts points for manufacturers, begin interactionFunding – the longer we wait, the more it costs

USGS partially funded in FY05 Establish IADIWG funding mechanisms required for FY05USGS and IADIWG need to define funding mechanisms for FY06 and FY07

Define infrastructure neededIn-situ rangesHardware and Software requirementsLaboratories – radiometry especially

Establish guidelines, policy, standards, and boiler plate specifications IADIWG involved in standards development & approvalIADIWG to begin specifying data “classes” in their work, requesting USGS standards, educating users & industry

Documents

Mapping the Path to Digital Sensor Calibration