Attachment P - SCTR SOW Appendix A Rev -.pdf

LandIS SOW Appendix A SCTR LNEXT-LANDIS-SOW-0005 Revision -ii

Special Calibration Test Requirements (SCTR) Appendix A to Landsat Instrument Suite (LandIS) Statement of Work (SOW)

Prepared by:

Electronic Signature in TDMS

12/13/2022 Joy Henegar-Leon Date Landsat Next Payload Technical Manager NASA/GSFC, Code 426

Approved by:

Wen-Ting Hsieh Date Landsat Next Payload Manager NASA/GSFC, Code 426

Evan Webb Date Landsat Next Systems Manager NASA/GSFC, Code 599

James Pontius Date Landsat Next Project Manager NASA/Goddard, Code 426 iii

CM Foreword This document is a Landsat Next Project Configuration Management (CM)-controlled document.

Changes to this document require prior approval of the applicable Configuration Control Board (CCB) Chairperson or designee. Proposed changes shall be submitted to the Landsat Next CM Office (CMO), along with supportive material justifying the proposed change. Changes to this document will be made by complete revision.

Questions or comments concerning this document should be addressed to:

NASA/Goddard Space Flight Center Landsat Next Project Office, Code 426 Attention: Configuration Management Office Greenbelt, Maryland 20771 iv

Change History Log Revision Effective Date Description of Changes

- 12/13/2022 LNEXT-CCR-0030 – Initial Release v

List of TBDs/TBRs Hyperlink to TBx Location Summary Ind.

Name/Org.

Due Date

TBx-1 Section 1.2.0-7

Note: The contractor will design ground support equipment (GSE) to meet Table A-1 requirements. If GSE capability permits, data will be acquired beyond the range specified in Table A-1 where the component build-up is > 0.005 (TBR). Best effort will be made to meet the signal-to-noise (SNR) requirements over the extra wavelength range, but noisier data will be considered compliant.

Instrument Science IPDR

TBx-2 Section 1.3

The contractor shall characterize the spatial edge response based on measurements at the integrated instrument level under simulated on-orbit operating conditions, pre- and post-vibration testing, and across the entire field of view (FOV) in all bands under the following conditions:

Measurement conditions (TBR):

- measurements spread out across the FOV at least covering the edges and center of the detector array(s)

- 0.05 instantaneous field of view (IFOV) increments from ± 3 IFOV from center of detector in both along-track and across-track directions

- 0.5 IFOV increments from 3 to 10 IFOV from center of detector in both along track and across-track directions

- At the nominal and the high and low acceptance temperatures

Instrument Science IPDR

TBx-3 Section 1.3

The test objects shall be scanned across the full FOV of the telescope and shall be verified through one of the following (TBR):

(1) At the integrated instrument level with a two-dimensional test object subtending a minimum of 1.5 degrees (°), or

(2) At the integrated instrument level with a two-dimensional test object subtending a minimum of 0.2° and at the subassembly or higher level of integration with a two-dimensional test object subtending a minimum of 1.5°. Verification using the 1.5° object can be achieved by combining sub-assembly (e.g., early focal plane integration level and telescope) tests data as inputs to an analysis using ray-trace and stray-light models.

Instrument Science IPDR vi

TBx-4 Section 1.7

The contractor shall characterize the 1/f noise parameters for all imaging and dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

Note: The 40 minutes (TBR) is meant to represent the approximate longest interval of continuous Earth imaging.

Instrument Science

Final

RFP

TBx-5 Section 1.7

The contractor shall characterize the stability of the instrument response for all imaging and dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

Instrument Science

Final

RFP

TBx-6 Section 1.7

The contractor shall characterize the predictability of the imaging detectors biases from the dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

Instrument Science

Final

RFP

TBx-7 Section 1.7

The contractor shall characterize the performance of the bias determination algorithm using on-orbit data for acquisition intervals of up to 40 minutes (TBR).

Instrument Science

Final

RFP

vii

Table of Contents CM FOREWORD ..........................................................................................................................III

CHANGE HISTORY LOG .......................................................................................................... IV

LIST OF TBDS/TBRS .................................................................................................................... V

TABLE OF CONTENTS ............................................................................................................. VII

LIST OF FIGURES ..................................................................................................................... VII

LIST OF TABLES ....................................................................................................................... VII

APPENDIX A SPECIAL CALIBRATION TEST REQUIREMENTS

A.1 General Test Requirements A.2 Pre-Flight Spectral Test Requirements A.3 Pre-Flight Spatial Test Requirements A.4 Pre-Flight Radiometric Test Requirements A.5 Pre-Flight Geometric Test Requirements A.6 On-Orbit Commissioning Phase Spatial Test Requirements A.7 On-Orbit Commissioning Phase Radiometric Test Requirements A.8 On-Orbit Commissioning Phase Geometric Test Requirements

List of Figures

No table of contents entries found.

List of Tables

Table A-1 Spectral Test Minimum Acceptable Requirements Table A-2 Radiometric Test Minimum Acceptable Requirements

Check https://ipdtdms.gsfc.nasa.gov to verify that this is the correct version prior to use.

Appendix A Special Calibration Test Requirements

A.1 GENERAL TEST REQUIREMENTS

Sampling methods and their statistical validity will be described in the Verification Reports, CDRL LandIS-SE-7.

Note: A discussion of plans for sampling and their statistical basis (if not specified by requirements) will be reported in the Calibration/Validation Plan, CDRL LandIS-CV-1.

The sampling of the instrument and focal plane temperatures to be used for the characterizations will be described in Verification Reports, CDRL LandIS-SE-7.

Note: A discussion of plans for instrument and focal plane temperatures will be reported in the Verification Plan.

SCTR-7 The contractor shall follow National Institute of Standards and Technology

(NIST) radiometric calibration standards for sources intended for instrument radiometric calibration.

SCTR-8 The contractor shall establish instrument saturation and damage thresholds in all spectral bands for a continuous wave (CW) optical input.

A.2 PRE-FLIGHT SPECTRAL TEST REQUIREMENTS

Rationale for spectral requirements: These spectral calibration tests are required in order to perform the radiometric calibration of the instrument and provide the user community the fundamental spectral characteristics of the data. The component-level measurements will be used to predict the system-level response and assure the final system will likely meet relative spectral response requirements; however, measuring the response on the assembled instrument in as close to operational conditions as possible is required for an adequate characterization. The spectral uniformity requirement, in particular, requires characterization of the variation in the system-level responses (Section 5.6.2.3 of LandIS RD). It is difficult to obtain sufficient energy to measure the out-of-band response at the integrated instrument level, so measurements at the sensor chip assembly (SCA) level are allowed for this characterization. Spectral bandpass filters have historically shown stability problems in the transition from ambient to vacuum conditions due to the outgassing of absorbed water. Current filter fabrication techniques have reduced this problem significantly; the tests here are intended to verify that the LandIS filters do not have this problem and will likely meet the spectral stability requirement for LandIS (Section 5.4.5 of LandIS RD). The spectral and radiometric characterizations of the integrated instrument will occur with the instrument in the thermal vacuum chamber and the calibration sources outside; a characterization of the spectral transmission of the optical window is thus required.

SCTR-11 The contractor shall measure the spectral transmission of the spectral bandpass filters per the parameters in Table A-1.

Rationale: The purpose of this requirement is to measure the transmission at the operational F/# and to test for angle resolved scatter from the filters at the wafer level.

SCTR-12 The contractor shall measure the relative spectral radiance response of a sample of witness detectors from the same detector wafers as the flight SCA per the parameters in Table A-1.

SCTR-13 The contractor shall measure the spectral transmission or reflectance of each optical element in the instrument optical path per the parameters in Table A- 1.

SCTR-14 The contractor shall measure the spectral transmission or reflectance of any focal plane array (FPA) windows per the parameters of Table A-1.

SCTR-15 The contractor shall measure the in-band relative spectral radiance response of the instrument per the parameters in Table A-1.

SCTR-16 The contractor shall determine the out-of-band relative spectral radiance response of the instrument for each band via measurements conducted per the parameters in Table A-1.

Note: If GSE capability permits, data can be acquired beyond the range specified in Table A-1 where the component build-up is > 0.005 (TBR). Best effort will be made to meet the signal-to-noise (SNR) requirements over the extra wavelength range, but noisier data will be considered compliant.

SCTR-18 The contractor shall characterize the stability of the spectral transmission of the spectral band bandpass filters between ambient pressure and vacuum conditions under operational conditions per the parameters in Table A-1.

SCTR-19 The contractor shall measure the spectral transmission of the thermal vacuum chamber optical window per the parameters in Table A-1.

A.3 PRE-FLIGHT SPATIAL TEST REQUIREMENTS

SCTR-21 The contractor shall characterize the spatial edge response based on measurements at the integrated instrument level under simulated on-orbit operating conditions, pre- and post-vibration testing, and across the entire field of view (FOV) in all bands under the following conditions:

Measurement conditions (TBR):

• Measurements spread out across the FOV at least covering the edges and center of the detector array(s)

• 0.05 instantaneous field of view (IFOV) increments from ± 3 IFOV from center of detector in both along-track and across-track directions

• 0.5 IFOV increments from 3 to 10 IFOV from center of detector in both along track and across-track directions

• At the nominal and the high and low acceptance temperatures

Rationale: Spatial response may be a function of location with the focal plane, hence the requirement to characterize across the entire FOV. NOTE: If applicable, Time Delay Integration

(TDI) should be turned off to allow the edge response to be oversampled. The effect of TDI on edge response performance will be evaluated by analysis.

SCTR-22 The contractor shall characterize the spatial edge response based on measurements at the integrated instrument level under simulated on-orbit operating conditions in all bands at two additional focus settings that bracket the best focus position at the center (FOV scale factor 0.07) and edges (FOV scale factors -0.97 and +0.97) of the field of view under the measurement conditions specified above SCTR-21.

Rationale: These measurements will be used to relate edge slope performance to the optical system’s focus setting. This will make it possible to use the focus adjustment capability to better balance on-orbit spatial performance between edge response slope and aliasing.

SCTR-23 If spatial measurements are done with the source outside the thermal vacuum chamber, the contractor shall measure the optical power and distortion of the thermal vacuum chamber optical window under expected thermal vacuum operating conditions.

Rationale: Spatial measurements performed through the chamber window will be affected by the window’s optical properties.

SCTR-24 The contractor shall characterize and analyze the stray light rejection and internal light scattering of the instrument based on measurements at the component level or above.

Rationale: These measurements and analysis will be used to verify LandIS light rejection (Section 5.5.4 of LandIS RD).

SCTR-25 The contractor shall develop a stray light model that encompasses the entire optical system, including baffles and the focal plane and mounting devices and all portions of the satellite bus and other payloads that may reflect or emit light into the sensor.

SCTR-26 The model shall be developed using a government-approved non-sequential ray trace method, e.g., ASAP, APART, GUERAP, Fred, or Trace Pro.

SCTR-27 The contractor shall validate the LandIS stray light model by stray light measurements at the integrated telescope level to the level needed to verify stray light requirements.

SCTR-28 The contractor shall update the stray light model to account for discrepancies between the stray light measurements and the stray light model that are beyond the combined model and measurement uncertainties.

Note: Integrated telescope level includes any baffle structures and apertures. It may exclude the flight FPA. However, the optical differences between the test FPA and the flight FPA should be accounted for in the model.

SCTR-30 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall include a stray light analysis of the calibrator in the deployed position.

SCTR-31 This analysis shall include glints and shadowing on the calibrator by other observatory structures as well as the instrument itself.

SCTR-32 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall validate, by measurements at the integrated instrument level, the completed flight calibration assembly in two separate bands: the calibrator's stray light model’s, excluding observatory effects, and prediction of the enhancement of the light reflected off the calibrator above that calculated using its inherent reflectance/transmission due to reflections off the instrument back to the calibrator to an uncertainty of 0.005 reflectance or less.

Rationale: This characterization will allow the solar calibrator to be used as an absolute calibration source; the observatory, the instrument itself, and the Earth may all contribute stray light to the solar calibrator.

SCTR-33 The contractor shall demonstrate that any on board calibration source (e.g., diffuser, blackbody, etc.) measurements on orbit are not contaminated by reflected or emitted light from the Earth and the atmosphere.

SCTR-34 The contractor shall analytically verify the ghosting requirements (Section

5.5.5 of the LandIS RD) are met by using the stray light model.

SCTR-35 The contractor shall verify ghosting requirements of the LandIS RD by test using broadband far-field illuminated test object(s).

SCTR-36 The test objects shall be scanned across the full FOV of the telescope and shall be verified through one of the following (TBR):

(1) At the integrated instrument level with a two-dimensional test object subtending a minimum of 1.5 degrees (°), or

(2) At the integrated instrument level with a two-dimensional test object subtending a minimum of 0.2° and at the subassembly or higher level of integration with a two-dimensional test object subtending a minimum of 1.5°. Verification using the 1.5° object can be achieved by combining sub-assembly (e.g., early focal plane integration level and telescope) test data as inputs to an analysis using ray-trace and stray-light models.

SCTR-37 In this case, the sub-assembly measurements shall emulate the effect of scanning this two-dimensional object anywhere in the LandIS telescope

FOV.

SCTR-38 For thermal band: The test object (at the integrated instrument level) shall be at least 0.2 deg x 0.2 deg with the data combined to demonstrate performance when imaging a 1.5 deg x 1.5 deg object.

A.4 PRE-FLIGHT RADIOMETRIC TEST REQUIREMENTS

SCTR-40 The contractor shall characterize the spatial and angular uniformity of the

GSE radiance calibration sources (e.g., integrating sphere, large-diameter blackbody, etc.) at each measured radiance level (i.e., lamp level, blackbody temperature, etc.).

Rationale: The uniformity of the calibration sources may affect the characterization of the instrument depending on the view geometry between the instrument FOV and calibration source.

SCTR-41 The contractor shall collect calibration data sets at the integrated instrument level to radiometrically calibrate all detectors to convert the instrument output in digital number (DN) to at-aperture spectral radiance.

SCTR-42 Independent characterization data sets shall be used to demonstrate that the calibrated data will meet the absolute radiometric accuracy, pixel-to-pixel uniformity and radiometric stability requirements on orbit. Data sets are acquired per the parameters in Table A-2.

Rationale: These tests provide the basic radiance calibration of the instrument. Data sets of the SI-traceable source are acquired over the required dynamic range of LandIS to provide adequate data to convert raw detector output into radiance. Data used in the determination of the calibration equations should be independent of the data used to characterize radiometric performance.

SCTR-43 The contractor shall characterize the non-linearity of the voltage response of the focal plane electronics (FPE) per the parameters in the Table A-2.

Rationale: The non-linearity of response of the instrument results from both detector and electronic effects, so component, assembly and integrated instrument level measurements are required to adequately characterize it.

SCTR-44 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall prepare the flight calibrator using the following steps:

SCTR-45 Step 1: The contractor shall vacuum bake out the flight calibrator material and measure released contaminants.

SCTR-46 Step 2: The contractor shall measure the Bidirectional Reflectance Distribution Function (BRDF) (or equivalent) of the flight calibrator materials after the bake out over the expected range of source and view geometries.

SCTR-47 Step 3: The contractor shall keep the flight calibrators and several (at least six) witness samples in a clean, sealed or purged environment when not in use.

SCTR-48 Step 4: The contractor shall subject some of the witness samples to lifetime ultraviolet exposure.

SCTR-49 Step 5: The contractor shall establish criteria for acceptable calibrator degradation due to ultraviolet exposure and reject any calibrator material lots that do not meet these criteria.

SCTR-50 Step 6: If the lot is rejected, flight calibrator preparation steps 1 through 6 (SCTR-45 thru SCTR-50) shall be performed with a new material lot.

SCTR-52 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, during Integration and Test (I&T) the contractor shall use test (non-flight) calibrators and several witness samples for all instrument and observatory I&T activities, except for those activities where by mutual agreement, the flight calibrators will be used.

SCTR-53 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, during Integration and Test (I&T) the contractor shall subject the witness samples, which accompanied the test (non-flight) calibrators during I&T, to ultraviolet damage testing and characterize their reflectance.

SCTR-54 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, during Integration and Test (I&T) the contractor shall select one witness sample, which accompanied the flight calibrators and subject the sample to ultraviolet damage testing and characterize its reflectance/transmission afterward.

SCTR-55 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, during Integration and Test (I&T) the contractor shall select another witness sample, which accompanied the flight calibrators, and subject the sample to vacuum bake out and ultraviolet damage testing and characterize its reflectance/transmission afterward.

SCTR-56 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, during Integration and Test (I&T), and if necessary, based on the results of the post I&T tests on the witness samples which accompanied the flight calibrators, the contractor shall subject the flight calibrators to vacuum bake out.

SCTR-57 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall create a plan to minimize contamination and degradation of the calibrator through I&T and launch.

SCTR-58 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall reserve, for potential post-launch analysis, at least two witness samples, which accompanied the flight calibrators and which did not undergo additional testing, and maintain the samples in a clean, sealed or purged environment.

SCTR-59 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall measure the absolute repeatability of reflectance/transmission due to solar calibrator deployment. Measurement of this repeatability at the system level constitutes characterizing the BRDF Factor (or equivalent) at operational angles.

SCTR-60 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall characterize the reproducibility instrument response under repeated calibrator deployments at the integrated instrument level.

Rationale: The solar calibrator provides the reflectance-based or transmission-based calibration of the instrument; the characterization of the reflectance or transmission and deployment angles of the calibrator are required to use it as a calibration source.

SCTR-61 If an internal illumination source is included on board, the contractor shall characterize the behavior of the illumination source at the integrated instrument level per the parameters in Table A-2 and provide a concept of operations for acquiring data from the illumination source.

Rationale: The internal light sources may provide a technique for monitoring the short-term stability of the radiometric calibration, i.e., minutes to days. The Contractor will specify and justify how often a measurement of the internal source will be needed.

SCTR-62 If an internal blackbody is included on board, the contractor shall characterize the spatial and angular distribution of the temperature and emissivity of the on board blackbody(s) at all operational set points.

SCTR-63 The characterization required in SCTR-62 shall be repeated at least twice.

Rationale: The on board blackbodies may provide the emitted radiance-based calibration of the instrument. Radiometric calibration is dependent on the repeatability of the Blackbody emitted radiance during on board calibrations; this test characterizes that stability and allows validation of the radiometric requirements. The need for at least two measurements is to demonstrate reproducibility. Exact timing is not critical.

SCTR-64 If an internal blackbody is included on board, the contractor shall characterize the temperature and radiance stability of the blackbody(s) over the planned time between instrument calibrations, and characterize the repeatability between successive calibration acquisitions per the parameters in Table A-2.

SCTR-65 The contractor shall acquire measurements of the on board calibration hardware (see LandIS RD section 5.8) at the integrated instrument-level to characterize the stability of the instrument response.

Rationale: Measurements of the on board hardware pre-flight are meant to parallel similar measurements on-orbit to assess the stability of the instrument and may factor into the radiometric transfer-to-orbit plan. Note: These measurements would be repeated on-orbit.

SCTR-66 The contractor shall characterize the signal to noise ratio (VNIR/SWIR) and the Noise Equivalent change in Temperature (NEdT) noise (TIR) (Section

5.6.2.1 of LandIS RD) of all detectors per the parameters in Table A-2.

SCTR-67 The contractor shall characterize the predictability of all imaging detector biases from the dark reference detectors for each SCA per the parameters in Table A-2.

SCTR-68 The contractor shall characterize the stability of the instrument response (bias and gain) and noise levels of all imaging and dark reference detectors under simulated on-orbit operating conditions per the parameters in Table A- 2.

Rationale: The stability of the instrument response over a long Earth imaging interval is fundamental to the performance of the image calibration algorithms and affects the overall radiometric uncertainty.

SCTR-69 The contractor shall characterize the baseline 1/f noise parameters for all imaging and dark reference detectors per the parameters in Table A-2.

SCTR-70 The contractor shall characterize the coherent noise of the instrument (Section 5.6.2.4 of LandIS RD) per the parameters in Table A-2.

SCTR-71 The contractor shall characterize the Degree of Linear Polarization (DoLP) sensitivity and azimuth angle of the semi-major axis for all view angles across the swath of the instrument (Section 5.6.4 of LandIS RD) by component level measurements (e.g., witness mirrors, lenses, optical filters, windows, detectors, etc.) and analysis.

SCTR-72 The contractor shall measure the Degree of Linear Polarization (DoLP) sensitivity and azimuth angle of the semi-major axis of a sampling of detectors from each band (at least center and edges of FOV) at the integrated instrument level to verify the polarization characterization performed by component level measurements and analyses per the parameters in Table A- 2.

SCTR-73 The contractor shall verify the bright target recovery requirements of the instrument (Section 5.6.6 of LandIS RD) per the parameters in Table A-2.

SCTR-74 The contractor shall provide and maintain a detector operability status list that includes dead, inoperable, and out-of-spec detectors for each band.

SCTR-75 The contractor shall characterize the radiometric sensitivity model for the instrument thermal environment, i.e., contributions of instrument emitted radiance to the instrument response per the parameters in Table A-2.

Rationale: The instrument contributes a signal to the detectors depending on its internal temperatures.

SCTR-76 The contractor shall estimate the time required to recover from various on-orbit operations that change the instrument environment, e.g., off-nadir viewing, lunar viewing, delta inclination maneuvers, etc., and reach radiometric performance requirements.

Rationale: Observatory maneuvers might disrupt the instrument thermal stability which could affect radiometric performance.

SCTR-77 The contractor shall characterize the detector bias and gain stability across expected on-orbit on-off cycling of the instrument per the parameters in Table A-2.

SCTR-78 The contractor shall characterize the coherent noise of the instrument per the parameters in Table A-2.

Rationale: Re-check coherent noise at observatory level to ensure no interference from spacecraft electronics.

A.5 PRE-FLIGHT GEOMETRIC TEST REQUIREMENTS

SCTR-80 The contractor shall determine each detector’s line of sight (LOS) relative to the contractor-defined instrument reference axes, to an accuracy ≤ 30 microradian (µrad) (3-sigma) VNIR/SWIR and ≤ 120 µrad (3-sigma) TIR, at the integrated instrument level. Note: The determination of the detectors lines of sight may be based on a combination of measurement and analysis.

Rationale: Band-to-band and image-to-image registration error budgets are driven by platform stability and LOS knowledge and stability. The current error budgets assume 3 µrad (3-sigma) LOS knowledge and stability (and 10 μrad (3-sigma) thermal LOS knowledge and 16 μrad (3-sigma) stability). Given the level of changes to the line-of-sight model expected through launch, an on-orbit calibration update is required to achieve this final level of accuracy. The prelaunch measurements need only be sufficiently accurate to demonstrate appropriate focal plane layout (e.g., swath coverage, IFOV) and to allow the on-orbit calibration methods to operate. On-orbit calibration is necessary to achieve this level of accuracy due to the potential for shift through launch.

SCTR-81 The contractor shall measure the VNIR/SWIR detector lines of sight by measuring the relative locations of a selected set of detectors with a repeatability ≤ 15 µrad (3-sigma), at integrated instrument level.

SCTR-82 The selected set of detectors shall include, at a minimum, the first, middle, and last detector from each band on each SCA.

Rationale: LOS stability (over the range of expected operating temperatures) of 2.4 µrad (3-sigma) VN IR/SWIR and 16 µrad (3-sigma) TIR or better is required by the current band registration and image registration error budgets.

Measurements to this level of accuracy are difficult to perform pre-launch so final stability will ultimately be verified on-orbit.

SCTR-83 The contractor shall characterize the relative stability of the TIR detector lines of sight by measuring the relative locations of a selected set of detectors from each band and each SCA at the nominal, maximum and minimum expected operating temperatures, to an accuracy ≤ 60 µrad (3-sigma), at integrated instrument or observatory level, post-vibration.

SCTR-84 The selected set of detectors shall, at a minimum, bind the set of active detectors for each band on each SCA.

SCTR-85 The selected set of detectors shall include a sampling of interior detectors such that no selected detector is more than 64 IFOVs from another selected detector.

Rationale: On-orbit LOS stability (over the range of expected operating temperatures) of 1.5 µrad (3-sigma) VNIR/SWIR and 8 µrad (3-sigma) TIR or better is required by the current band registration and image registration error budgets. Measurements to this level of accuracy are difficult to perform pre-launch so final stability will ultimately be verified on-orbit.

SCTR-86 The contractor shall characterize the detector-sampling timing pattern, to an accuracy of 50 microseconds (3-sigma) VNIR/SWIR and 50 microseconds (3-sigma) TIR or better, via measurement of any detector-specific electronic delays, sample phasing (e.g., even/odd detector timing offsets), and frame rate (i.e., time between samples) for each detector.

Rationale: Detector to detector timing/latency variations must not significantly degrade the LOS knowledge of 3 µrad (3-sigma). Timing knowledge to 50 microseconds corresponds to an additional LOS uncertainty of approximately 1.5 µrad.

SCTR-87 The contractor shall measure the alignment of the contractor-defined instrument reference axes relative to the LandIS alignment reference/alignment cube, before and after instrument vibration testing.

Rationale: Demonstrating overall alignment stability through vibration testing provides confidence that the instrument will not experience excessive alignment shift through launch.

SCTR-88 Following observatory-level vibration testing, the contractor shall demonstrate that the data from the detectors are mapped to the correct locations in the observatory downlink data stream.

Rationale: This observatory level test is intended to demonstrate that the instrument and spacecraft data handling systems were successfully integrated and that no data connections were damaged during vibration testing. An internal source that provides input that varies across the focal plane should be sufficient for verifying the integrity of the data path.

Note: This test may be performed using an internal source.

A.6 ON-ORBIT COMMISSIONING PHASE SPATIAL TEST REQUIREMENTS

SCTR-90 The contractor shall examine the stray light and ghosting of the instrument using the Moon.

Rationale: Although a true characterization of the stray light response and ghosting is not possible using the Moon, the data can be examined for effects that are not predicted by the stray light model. In other instruments, e.g., TIRS, ALI, and ASTER lunar views have revealed stray light and ghosting issues.

A.7 ON-ORBIT COMMISSIONING PHASE RADIOMETRIC TEST REQUIREMENTS

SCTR-92 The contractor shall characterize the stability of the instrument by reference to the internal calibration hardware (described in LandIS section 5.8) by a minimum of daily measurements.

SCTR-93 If an internal illumination source is included on board, the contractor shall characterize its on-orbit performance and stability including warm-up behavior and within and between orbit stability relative to the instrument.

SCTR-94 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall characterize the variation in the bidirectional reflectance (or equivalent) of the calibrator across the range of azimuth and zenith angles to be used for on-orbit calibration.

SCTR-95 If a solar calibrator (e.g., diffuser, perforated plate, etc.) is included on board, the contractor shall characterize the reproducibility of the solar calibration technique with a minimum of five measurements, with each measurement acquired a minimum of 1 day apart.

SCTR-96 The contractor shall complete the on-orbit portion of the transfer to orbit measurement.

SCTR-97 The contractor shall update the absolute calibration coefficients and uncertainties as required to meet performance specifications.

SCTR-98 The contractor shall characterize the relative detector response for detectors within a band and update the calibration parameters to correct pixel-to-pixel non-uniformity as necessary.

SCTR-99 If outgassing is required, the contractor shall characterize any variations in detector responsivity over a minimum of two instrument outgassing cycles.

SCTR-100 The contractor shall characterize both the coherent and total noise of the instrument at dark and at multiple (at least two) illuminated levels between dark and Lhigh (VNIR/SWIR) and at a minimum of three radiance levels between 260K and 330K (TIR) at least twice with data acquired at least 15 days apart.

Note: there is no significance to the 15-day time period. The idea behind this spacing between measurements is to repeat the measurements at another time in the near future.

SCTR-101 The contractor shall characterize the 1/f noise parameters for all imaging and dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

Note: The 40 minutes (TBR) is meant to represent the approximate longest interval of continuous Earth imaging.

SCTR-102 The contractor shall characterize the stability of the instrument response for all imaging and dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

SCTR-103 The contractor shall characterize the predictability of the imaging detectors biases from the dark reference detectors over a 40-minute (TBR) period at least twice, with data acquired a minimum of 15 days apart.

SCTR-104 The contractor shall characterize the performance of the bias determination algorithm using on-orbit data for acquisition intervals of up to 40 minutes

(TBR).

SCTR-105 For each operational Landsat Next Observatory, the contractor shall support collection of data of common ground targets within 20 minutes of each operational Landsat’s acquisitions.

SCTR-106 The contractor shall update the detector operability status list with newly identified dead, inoperable, and out-of-spec detectors for each band.

Rationale: To the extent possible, the pre-launch radiometric tests need to be repeated on orbit to assess whether anything has changed since pre-launch testing and to characterize the system under its actual operating conditions. Noise levels, particularly coherent noise, may change with the change in grounding of the spacecraft. The radiometric response, both absolute and relative, may change during launch. Calibration techniques not readily available prior to launch, e.g., solar and lunar calibration, need to be conducted and their repeatability assessed.

SCTR-107 The contractor shall validate the radiometric sensitivity model for the instrument thermal environment, i.e., the contributions of instrument emitted radiance to the instrument response.

SCTR-108 The contractor shall validate the recovery time that it takes to return to nominal image performance after routine planned operations such as decontamination mode, off-nadir collects longest period, and other bus maneuvers.

SCTR-109 During the imaging-related maneuvers (e.g., lunar scans, off-nadir views, etc.), the contractor shall characterize the response stability of the instrument and any onboard sources.

Rationale: The intent is to characterize any instability in the instrument that would affect the accuracy of the image data acquired during the maneuver imaging. Instrument temperature telemetry may be used along with the radiometric sensitivity model.

A.8 ON-ORBIT COMMISSIONING PHASE GEOMETRIC TEST REQUIREMENTS

SCTR-111 The contractor shall characterize the instrument to Attitude Determination

System Reference alignment.

Rationale: The instrument alignment is expected to change due to launch shift and zero-G release, so an on-orbit update is required to achieve the required on-orbit geodetic accuracy performance. The accuracy is here left as a component of the overall geodetic error budget to be determined by the contractor. Internal error budgets call for an alignment calibration accuracy of 9 urad (3-sigma).

SCTR-112 The contractor shall characterize the detector arrays lines of sight relative to each other using ground targets at least twice, using data acquired at least 18 days apart once the observatory is settled into the final WRS-3 orbit.

Rationale: The prelaunch LOS calibration could change on-orbit due to the reaction of the optical system to launch and/or zero-G release. Any such changes would be expected to be slowly varying (not detector-by-detector) and subject to calibration using SCA-level on-orbit adjustments. The accuracy is here left as a component of the overall band registration error budget to be determined by the contractor. Internal error budgets call for a reflective band alignment calibration accuracy of 1.5 μrads (3-sigma). Internal error budgets call for a thermal band to reflective band alignment calibration accuracy of 10 μrads (3-sigma) and a thermal band to thermal band alignment calibration accuracy of 9 μrads (3-sigma).

SCTR-113 The contractor shall characterize the alignment of the atmospheric bands relative to the other reflective bands using scans of the Moon.

Rationale: The band alignment procedure used for the reflective bands (see previous requirement) is unlikely to be effective for the Cirrus band, which will not provide clear images of ground targets. Instead, this procedure must be carried out using the lunar scan data. The accuracy is here left as a component of the overall band registration error budget to be determined by the contractor. Internal error budgets call for a band alignment calibration accuracy of 1.5μrads (3-sigma).

SCTR-114 The contractor shall characterize the relative locations of the individual

SCAs on the focal plane at least twice, using data acquired at least 18 days apart.

Rationale: The prelaunch line-of-sight calibration could change on-orbit due to the reaction of the optical system to launch and/or zero-G release. Any such changes would be expected to be slowly varying (not detector-by-detector) and subject to calibration using SCA-level on-orbit adjustments. Once on-orbit, these LOS measurements are necessarily relative, so the calibration operation measures the offsets of each SCA relative to the mean of the SCAs. The accuracy is here left as a component of the overall image-to-image registration error budget to be determined by the contractor. Internal error budgets call for an SCA alignment calibration accuracy of 3 μrads3-sigma).

LandIS SOW Appendix A

SCTR

LNEXT-LANDIS-SOW-0005

Table A-1 Spectral Test Minimum Acceptable Requirements

ID Assembly Level

Unit Measurement Conditions

Samples Wavelength Range

Wavelength Sampling and Wavelength Resolution(FWHM)1

Precision in Response2

Other

SCTR-11 Component Filter Operational angular and temperature conditions (cover range of angles and temperatures expected)

3X3 per flight filter wafer

VNIR: 300-

1100 nm;

SWIR: 800-

3000 nm;

TIR: 0.3-30 μm or where detector response and optics transmission/ reflectance exceed 0.001 of peak.

VNIR/SWIR: 1 nm steps;

TIR: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

SNR>300 in-band; (TBR)

SCTR-12 Component Detector Operational angular and temperature conditions (cover range of angles and temperatures expected)

1% of detectors uniformly distributed across each flight array per band

VNIR: 350-

1100 nm;

SWIR: 800-

3000 nm;

TIR: 0.3-30 μm or where detector response exceeds 0.001 of peak

VNIR/SWIR: 1 nm steps;

TIR: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

SCTR-13 Component Optical Elements or Witness Samples

Operational angular and temperature conditions (cover range of angles and temperatures expected)

3 samples of each optical material

(TBR)

VNIR/SWIR:

300 nm to 3000 nm;

TIR: 0.3-30 μm or where predicted optics trans exceeds

0.001 of peak

VNIR/SWIR: 1 nm steps;

TIR: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

ID Assembly Level

Unit Measurement Conditions

Samples Wavelength Range

Wavelength Sampling and Wavelength Resolution(FWHM)1

Precision in Response2

Other

SCTR-14 Component Optical Surfaces or Witness Samples

Operational angular and temperature conditions (cover range of angles and temperatures expected)

3 samples of each optical surface

VNIR/SWIR:

300 nm to 3000 nm;

TIR: 0.3-30 μm or where predicted optics trans exceeds

0.001 of peak

VNIR/SWIR: 1 nm steps;

TIR: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

SCTR-15 Integrated

Vacuum, operational focal plane temperature

10% of detectors uniformly distributed across focal plane.

Between 0.005 response points

VNIR/SWIR: 1 nm;

TIR: 100 nm (TBR)

VNIR/SWIR:

0.01 (1 σ) above 0.1 RSR;

SNR >10 below

0.1 RSR;

TIR: 0.005 (1

σ) (TBR)

SCTR-16 Assembly or above

Mated Filter/ Detector Assembly Level or above

Operational angular and temperature conditions with adjacent bands illuminated

80% of all operational pixels (TBR)

VNIR: 350 nm to 1100 nm;

SWIR: 800 nm to 2500 nm;

TIR: 0.3-30 μm or where detector response and optics transmission/ reflectance exceeds 0.001 of peak.

VNIR/SWIR: 10 nm below 1 μm, 20 nm above 1 μm ;

TIR: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

ID Assembly Level

Unit Measurement Conditions

Samples Wavelength Range

Wavelength Sampling and Wavelength Resolution(FWHM)1

Precision in Response2

Other

SCTR-18 Component Filter witness samples

Ambient conditions then in vacuum after 1, 3, 5 and 7 days of vacuum exposure

1 filter VNIR band, 1 filter SWIR band, 1 filter TIR band, with 1 spot per filter

VNIR: 300-

1100 nm;

SWIR: 800-

3000 nm;

TIR: 0.3-30 μm or where detector response and optics transmission/ reflectance exceeds 0.001 of peak.

VNIR/SWIR: Out of band: 5 nm below 1 μm, 10 nm above 1 μm TIR: In-band: 50 nm, Out-of-band: 500 nm

The ratio of the Peak Signal (in-band) to RMS Noise out of band > 104;

SCTR-19 Calibration Equipment

Optical Window(s)

Ambient Conditions

10 spots VNIR/SWIR:

300 nm to 3000 nm;

TIR: 0.3-30 μm or where predicted optics trans exceeds

0.001 of peak

VNIR/SWIR: Within any band's in-band response: 1 nm below 1 μm; 2 nm above 1 μm;

Out-of-band: 5 nm below 1 μm, 10 nm above 1 μm;

TIR: In-band: 50 nm, Out-of-band: 500 nm

0.001 (1 σ) in band; SNR of >10 down to

0.0005 of peak

(TBR)

Table A-2 Radiometric Test Minimum Acceptable Requirements ID Assembly Level Measurement

Ambient Atmospheric

Measurement Temperature Conditions

Radiance Levels Calibration Source Location

Comments

SCTR-41

SCTR-42

Integrated Instrument

Thermal Vacuum (nominal and high and low temperature plateau)

Nominal controlled operational focal plane and instrument/ telescope temperatures

VNIR/SWIR/TIR: dark and 20 (TBR) levels uniformly spanning the required dynamic range.

(subset number of levels for low and high plateaus)

In chamber or viewed through chamber window

SCTR-43 Focal Plane Electronics

Nominal operational FPE temperature

Present a DC biased pure (very low THD) Sine-wave signal into FPE electronics to get a high SNR electronics non-linearity for each FPM chain

Internal Sources (if included) to be operated to verify and update their characterization during these tests

SCTR-61 Integrated Instrument

Thermal Vacuum (nominal and high and low temperature plateau)

Nominal operational focal plane temperature

Internal Lamps (if included) to be operated and warm-up behavior characterized during these tests;FPA reset as per on-orbit ops

SCTR-64 Integrated Instrument

Thermal Vacuum Nominal operational focal plane temperature

One external blackbody temperature;

measurements over time period between planned calibration acquisitions (may be sampled) in simulated orbits, three repeats

Internal Blackbodies to be operated during these tests

ID Assembly Level Measurement Ambient Atmospheric

Measurement Temperature Conditions

Radiance Levels Calibration Source Location

Comments

SCTR-66 Integrated Instrument

Thermal Vacuum (nominal and high and low temperature plateau)

Nominal operational focal plane temperature

VNIR/SWIR/TIR: 10

(TBR) levels uniformly spanning the required dynamic range (subset number of levels for low and high plateaus)

SCTR-67 Integrated

Thermal Vacuum Nominal operational focal plane temperature

Dark Level, measurements over 40 minutes (TBR) (may be sampled non-contiguously) three repeats

SCTR-68 Integrated

Thermal Vacuum Nominal operational focal plane temperature

Dark and 1 level near Lref, measurements over 40 minutes (TBR) (may be sampled non-contiguously), three repeats

SCTR-69 Integrated

Thermal Vacuum (nominal temperature)

Nominal operational focal plane temperature

VNIR/SWIR: Dark level measurements over a 40-minute period (TBR) TIR: One external blackbody temperature over 40 minutes (TBR)

SCTR-70 Integrated

Thermal Vacuum (nominal temperature)

Nominal operational focal plane temperature

Dark and 1 level near Lref (TBR)

SCTR-72 Integrated

Nominal operational focal plane temperature

SCTR-73 Focal plane level or above

Nominal operational focal plane temperature

ID Assembly Level Measurement Ambient Atmospheric

Measurement Temperature Conditions

Radiance Levels Calibration Source Location

Comments

SCTR-75 Integrated Instrument

Thermal Vacuum (high and low temperature plateaus)

Nominal operational focal plane temperature

1 level near Lref

(TBR)

Each instrument control temperature to be separately varied during this test: electronics, optics, housing, etc.

SCTR-77 Integrated Instrument

Thermal Vacuum Nominal operational focal plane temperature

1 level near Lref

(TBR)

SCTR-78 Observatory Thermal Vacuum (high and low temperature plateaus)

At each operational focal plane temperature set point

Dark Level (TBR)