Orbital variations and impacts on observations from SNPP, NOAA 18-20, and AQUA sun-synchronous satellites
Open accessAbstract
The AQUA, SNPP, and NOAA 18-20 PM sun-synchronous satellites were designed with similar local time, local solar zenith angles, and overlapping temporal coverage. Although the satellites are expected to have fixed local equator- crossing time, during the satellite lifetime, the equator-crossing times of these satellites drift. For NOAA 18-19, the drift in equator-crossing time is significant (few hours) and no correction has been done over the lifetime. For SNPP and AQUA, correction in the orbital inclination angle was periodically performed to maintain the equator-crossing time around the designed value. The impact of systematic drift of the local observation time during the satellite life cycle can be significant and should be accounted for when using multi-year time series of satellite products in long-term environmental studies. In this paper, the equator-crossing time drift of AQUA, SNPP, and NOAA 18-20, the correction of SNPP and AQUA equator-crossing time via orbital inclination angle change, and the consequent local solar zenith angle variation are evaluated. The impact of such drift on low-latitude mean brightness temperature trend derived from the similar ~11 μm thermal emissive channel of AQUA MODIS CH31, SNPP Visible Infrared Imaging Radiometer Suite (VIIRS) CH15 and NOAA 18-19 HIRS CH08 are analyzed. The drift in the mean brightness temperature measured by these sensors is combined as a function of local time and analyzed using diurnal cycle analysis. The mean brightness temperature drift for SNPP VIIRS is reconciled within the context of much larger temperature drift of NOAA 18-19.
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- Findingnone given
Follow-up adjustments were applied in ~ yearly interval to maintain the equator-crossing time of SNPP around 13:25 PM.
“The follow-up adjustments were applied in ~ yearly interval to maintain the equator-crossing time of SNPP around 13:25 PM.”
Quote in the paperNot a substantial claim - Findingreasoning
Due to lack of orbital correction, the equator-crossing time of NOAA 18-19 is the most significant.
“Due to lack of orbital correction, the equator-crossing time of NOAA 18-19 is the most significant.”
Quote in the paperNot a substantial claim - Findingnone given
There is no orbital correction for NOAA 19.
“There is no orbital correction for NOAA 19.”
Quote in the paperNot a substantial claim - Findingnone given
Due to the orbital drift of NOAA18, its equator-crossing time of ascending orbit drifted from its initial location at ~ 14:00 PM to 19:30 PM in late 2017 when NOAA 18 satellite became terminator crossing satellite.
“Due to the orbital drift of NOAA18, its equator-crossing time of ascending orbit drifted from its initial location at ~ 14:00 PM to 19:30 PM in late 2017 when NOAA 18 satellite became terminator crossing satellite.”
Quote in the paperSubstantial claim - Findingown data
Since its launch, the equator-crossing time of NOAA 18 drifts from initial 14:00 PM to 13:30 PM and then to ~19:50 PM, i.e. terminator orbit.
“Since its launch, the equator-crossing time of NOAA 18 drifts from initial 14:00 PM to 13:30 PM and then to ~19:50 PM, i.e. terminator orbit.”
Quote in the paperSubstantial claim
- Findingown data
Before 2012, the equator crossing time of AQUA is between 13:31:48 and 13:40:48 PM.
“Before 2012, the equator crossing time of AQUA is between 13:31:48 and 13:40:48 PM.”
Quote in the paperNot a substantial claim - Findingown data
The equator-crossing time drift for SNPP accumulates to ~10 min in late 2014 when major orbital adjustments were applied.
“On the other hand, the equator-crossing time drift for SNPP accumulates to ~10 min in late 2014 when major orbital adjustments were applied.”
Quote in the paperNot a substantial claim - Findingnone given
During the satellite lifetime, the equator-crossing times of these satellites drift.
“Although the satellites are expected to have fixed local equatorcrossing time, during the satellite lifetime, the equator-crossing times of these satellites drift.”
- Also stated in: § 1. INTRODUCTION · plain
“During the satellite lifetime, the equatorcrossing times of these satellites drift.”
Quote in the paperSubstantial claim - Also stated in: § 1. INTRODUCTION · plain
- Findingown data
The equator-crossing time of NOAA 19 varies from initial 14:00 PM to 13:30 PM and then to current 16:00 PM over nine years.
“The equator-crossing time of NOAA 19 varies from to initial 14:00 PM to 13:30 PM and then to current 16:00 PM over nine years.”
Quote in the paperNot a substantial claim - Findingreasoning
The mean local solar zenith angle of NOAA 19 continues to increase due to the uncontrolled orbital drift.
“The mean local solar zenith angle of NOAA 19 continues to increase due to the uncontrolled orbital drift.”
Quote in the paperNot a substantial claim - Findingown data
The overall variation range of the mean solar zenith angle is about 10 degree when the selected latitude region varies between -30 to 30 degree in latitude.
“The overall variation range of the mean solar zenith angle is about 10 degree when the selected latitude region varies between -30 to 30 degree in latitude.”
Quote in the paperNot a substantial claim - Findingnone given
Since its launch in November, 2017, the equator-crossing time of NOAA-20 is within 1 minute around 13:25 PM.
“Since its launch in November, 2017, the equator-crossing time of NOAA-20 is within 1 minute around 13:25 PM.”
Quote in the paperNot a substantial claim - Findingown data
With ~2.5 hour drift in the equator-crossing time of NOAA 19 since 2012, the deviation in the solar zenith angle from its initial value is about 20 degree.
“With ~2.5 hour drift in the equator-crossing time of NOAA 19 since 2012, the deviation in the solar zenith angle from its initial value is about 20 degree.”
Quote in the paperSubstantial claim - Findingreasoning
Since the equator-crossing time of AQUA was tightly controlled, the solar zenith angle maintains almost unchanged.
“Since the equator-crossing time of AQUA was tightly controlled, the solar zenith angle maintains almost unchanged as shown in Figure 4b.”
Quote in the paperSubstantial claim - Findingnone given
Since 2012, the equator crossing time of AQUA has been tightly maintained between 13:35:00 and 13:36:30 PM.
“Since 2012, the equator crossing time of AQUA has been tightly maintained between 13:35:00 and 13:36:30 PM.”
Quote in the paperNot a substantial claim - Findingnone given
For SNPP and AQUA, correction in the orbital inclination angle was periodically performed to maintain the equator-crossing time around the designed value.
“For SNPP and AQUA, correction in the orbital inclination angle was periodically performed to maintain the equator-crossing time around the designed value.”
Quote in the paperSubstantial claim - Findingnone given
In comparison, there were no orbital inclination angle adjustments for NOAA 18-19.
“In comparison, there were no orbital inclination angle adjustments for NOAA 18-19.”
Quote in the paperSubstantial claim - Findingreasoning
When NOAA 18 approaches the terminator orbit, there is a cross-over between the BT sampled during ascending and descending orbits.
“When NOAA 18 approaches the terminator orbit, there is a cross-over between the BT sampled during ascending and descending orbits.”
Quote in the paperNot a substantial claim - Findingreasoning
Since the NOAA 18 and 19 instruments have larger local time drift, the fitted curve is dominated by the data from HIRS of these two satellites.
“Since the NOAA 18 and 19 instruments have larger local time drift, the fitted curve is dominated by the data from HIRS of these two satellites.”
Quote in the paperSubstantial claim - Findingnone given
The discrete orbital inclination angle adjustments to tightly maintain equator-crossing time for AQUA and SNPP were identified.
“The discrete orbital inclination angle adjustments to tightly maintain equator-crossing time for AQUA and SNPP were identified.”
Quote in the paperSubstantial claim - Findingown data
The long term trend due to the orbital drift can be clearly identified in the low latitude mean BT of NOAA 18 and 19.
“The long term trend due to the orbital drift can be clearly identified in the low latitude mean BT of NOAA 18 and 19.”
Quote in the paperSubstantial claim - Findingown data
The amplitude of annual oscillation in the low latitude mean BT data of NOAA 18 can be as large as 8 K over one side of hemisphere.
“The amplitude of annual oscillation in the low latitude mean BT data of NOAA 18 can be as large as 8 K over one side of hemisphere as shown in Figure 5.”
Quote in the paperSubstantial claim - Findingreasoning
With the fitted function of diurnal variation and given the equator crossing time drift of 10 minutes, the drift in low latitude mean BT for SNPP VIIRS is estimated to be 0.084K and 0.028K for the ascending and descending orbit, respectively.
“With the fitted function of diurnal variation and given the equator crossing time drift of 10 minutes, the drift in low latitude mean BT for SNPP VIIRS is estimated to be 0.084K and 0.028K for the ascending and descending orbit, respectively.”
Quote in the paperNot a substantial claim - Findingown data
The cross over between the ascending and descending low latitude mean BT of NOAA 18 can also be identified when it drifts to the terminator orbit.
“The cross over between the ascending and descending low latitude mean BT of NOAA 18 can also be identified when it drifts to the terminator orbit.”
Quote in the paperNot a substantial claim - Findingown data
After combining the data from both hemispheres, the remnant fluctuation in the low latitude mean BT is less than 2 K.
“After combining the data from both hemispheres, the remnant fluctuation in the low latitude mean BT is less than 2 K.”
Quote in the paperSubstantial claim - Findingown data
The fitted diurnal curve reconciles well the combined low latitude mean BT data of ascending and descending orbits.
“The fitted diurnal curve reconciles well the combined low latitude mean BT data of ascending and descending orbits.”
Quote in the paperSubstantial claim - Interpretationreasoning
The impact of systematic drift of the local observation time during the satellite life cycle can be significant.
“The impact of systematic drift of the local observation time during the satellite life cycle can be significant and should be accounted for when using multi-year time series of satellite products in long-term environmental studies.”
Quote in the paperSubstantial claim - Interpretationown data
Adjustment in SNPP orbital inclination angle helps maintain its equator-crossing time at designed value.
“Adjustment in SNPP orbital inclination angle helps maintain its equator-crossing time at designed value.”
Quote in the paperSubstantial claim - Interpretationreasoning
A direct consequence of the LEO satellite equator-crossing time variation can be reflected in the change of the local solar zenith angle when the satellite makes measurements.
“A direct consequence of the LEO satellite equator-crossing time variation can be reflected in the change of the local solar zenith angle when the satellite makes measurements.”
Quote in the paperSubstantial claim - Premisecitation
The change in the solar local time of observation can be closely tracked by the changes in the local time when the satellite crosses the equator.
“The change in the solar local time of observation can be closely tracked by the changes in the local time when the satellite crosses the equator [6,7], i.e. equator-crossing time during its ascending orbit.”
Quote in the paperSubstantial claim0 of 2 sources checked- cites [6]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- cites [7]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Interpretationreasoning
The remnant fluctuation in the low latitude mean BT can be attributed to the slightly different overpassing local time originated from the inclined orbital plane and difference in surface feature between low latitude regions in northern and southern hemisphere.
“The remnant fluctuation in the low latitude mean BT can be attributed to the slightly different overpassing local time originated from the inclined orbital plane and difference in surface feature between low latitude regions in northern and southern hemisphere.”
Quote in the paperNot a substantial claim
- May combine two claims. 11
May combine two claims.
Findingown dataOver six years since 2012, NOAA 19 equator-crossing time drifts about 2.5 hours as the orbital inclination angle continuously increases from 98.85 degree to 99.09 degree.
“Over six years since 2012, NOAA 19 equator-crossing time drifts about 2.5 hours as the orbital inclination angle continuously increases from 98.85 degree to 99.09 degree as shown in Figure 3.”
Quote in the paperSubstantial claimMay combine two claims.
FindingreasoningThe variation of the solar zenith angle peaked with a maximum of ~ 2.5 degree in late 2014 which corresponds to the equator-crossing time drift of ~10 min.
“The variation of the solar zenith angle peaked with a maximum of ~ 2.5 degree in late 2014 which corresponds to the equator-crossing time drift of ~10 min.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe equator-crossing time of SNPP drifts from initial 13:25 PM to as large as 13:33 PM in late 2014 and the corresponding orbital inclination angle changes from 98.675 degree to 98.79 degree.
“The equator-crossing time of SNPP drifts from initial 13:25 PM to as large as 13:33 PM in late 2014 and the corresponding orbital inclination angle changes from 98.675 degree to 98.79 degree.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe orbital adjustment of AQUA occurs yearly which helps maintain a tighter equator-crossing time drift than SNPP.
“The orbital adjustment of AUQA occurs yearly which helps maintain a tighter equator-crossing time drift than SNPP.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingnone givenFor NOAA 18-19, the drift in equator-crossing time is significant (few hours) and no correction has been done over the lifetime.
“For NOAA 18-19, the drift in equator-crossing time is significant (few hours) and no correction has been done over the lifetime.”
Quote in the paperSubstantial claimMay combine two claims.
Findingnone givenThe latitude region in the southern hemisphere has higher solar zenith angle, which is due to the inclination of the satellite orbital plane.
“The latitude region in the southern hemisphere has higher solar zenith angle, which is due to the inclination of the satellite orbital plane.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataFour consecutive orbital adjustments were applied in late 2014 to bring the orbital inclination angle to 98.68 degree and the equator-crossing time drifted afterwards toward 13:25 PM.
“Four consecutive orbital adjustments were applied in late 2014 to bring the orbital inclination angle to 98.68 degree and the equator-crossing time drifted afterwards toward 13:25 PM.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataFor AQUA, the orbital inclination angle was maintained between 98.19 and 98.23 degree and when the inclination angle approached 98.23 degree, four to five consecutive orbital adjustments were performed to maintain the equator-crossing time around the designed value.
“For AQUA, the orbital inclination angle was maintained between 98.19 and 98.23 degree and when the inclination angle approached 98.23 degree, four to five consecutive orbital adjustments were performed to maintain the equator-crossing time around the designed value.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataBoth NOAA 18 and 19 show continuous decreasing and increasing trend in the data collected during ascending and descending orbit, respectively.
“Both show continuous decreasing and increasing trend in the data collected during ascending and descending orbit, respectively.”
- Also stated in: § 5. SUMMARY · plain
“The long term low latitude mean BT of NOAA 18 and 19 showed continuous decreasing and increasing trend for the data collected during ascending and descending orbit, respectively.”
Quote in the paperSubstantial claim- Also stated in: § 5. SUMMARY · plain
May combine two claims.
Findingnone givenTheir orbital inclination angle continues to increase together with the equator-crossing time drifting toward terminator orbit.
“Their orbital inclination angle continues to increase together with the equator-crossing time drifting toward terminator orbit.”
Quote in the paperSubstantial claimMay combine two claims.
FindingreasoningThe BT sampled during ascending orbit continued to decrease while the BT sampled during descending orbit continued to increase.
“The BT sampled during ascending orbit continued to decrease while the BT sampled during descending orbit continued to increase.”
Quote in the paperSubstantial claim
The paper relies on this without support.
The AQUA, SNPP, and NOAA 18-20 PM sun-synchronous satellites were designed with similar local time, local solar zenith angles, and overlapping temporal coverage.
“The AQUA, SNPP, and NOAA 18-20 PM sun-synchronous satellites were designed with similar local time, local solar zenith angles, and overlapping temporal coverage.”
The paper relies on this without support.
The ~11 µm channel is primarily used for surface temperature retrieval.
“This ~11 µm channel is primarily used for surface temperature retrieval.”
The paper relies on this without support.
The local solar zenith angle has large annual variation due to the annual variation in the solar declination angle, which can mask the embedded small solar zenith angle change due to the orbital drift.
“The local solar zenith angle has large annual variation due to the annual variation in the solar declination angle, which can mask the embedded small solar zenith angle change due to the orbital drift.”
The paper relies on this without support.
By averaging the BT in low latitude region consisting of both northern and southern hemisphere, the annual cycle oscillation in BT can be canceled out to certain extent.
“By averaging the BT in low latitude region consisting of both northern and southern hemisphere, the annual cycle oscillation in BT can be canceled out to certain extent.”
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Self-citationOn‐orbit calibration and inter‐comparison of Terra and Aqua MODIS surface temperature spectral bands
Xiong, X., Wu, A., & Cao, C. (2008) · International Journal of Remote Sensing · doi:10.1080/01431160802036300
Self-citationSuomi NPP VIIRS sensor data record verification, validation, and long‐term performance monitoring
Cao, C., Xiong, J., Blonski, S., et al. (2013) · Journal of Geophysical Research: Atmospheres · doi:10.1002/2013jd020418
Self-citationCao, C., Luccia, F. J. D., Xiong, X., et al. (2014) · IEEE Transactions on Geoscience and Remote Sensing · doi:10.1109/tgrs.2013.2247768
Self-citationEquator crossing times for NOAA, ERS and EOS sun-synchronous satellites
Ignatov, A., Laszlo, I., Harrod, E. D., et al. (2004) · International Journal of Remote Sensing · doi:10.1080/01431160410001712981
Quantification of Impact of Orbital Drift on Inter-Annual Trends in AVHRR NDVI Data
Nagol, J., Vermote, E., & Prince, S. (2014) · Remote Sensing · doi:10.3390/rs6076680
Lindfors, A. V., Mackenzie, I. A., Tett, S. F. B., et al. (2011) · Journal of Atmospheric and Oceanic Technology · doi:10.1175/jtech-d-11-00093.1
Climate Model–Simulated Diurnal Cycles in HIRS Clear-Sky Brightness Temperatures
MacKenzie, I. A., Tett, S. F. B., & Lindfors, A. V. (2012) · Journal of Climate · doi:10.1175/jcli-d-11-00552.1
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Flagged first, then by citations
9 of the 9 references couldn’t be matched to a known paper.
Cited by
Sorted by citations
The Reprocessed Suomi NPP Satellite Observations
Zou, C., Zhou, L., Lin, L., Sun, N., Chen, Y., Flynn, L. E., Zhang, B., Cao, C., Iturbide‐Sánchez, F., Beck, T., et al. (2020) · Remote Sensing · doi:10.3390/rs12182891 · Cited by 32 · see citing works
“028 K for nighttime passes due to a flat temperature diurnal gradient near 1:30 am local time [93], although orbital drift is also of 10-min magnitude between the two satellites.”
BackgroundInfluentialSelf-citationAn Ongoing Blended Long-Term Vegetation Health Product for Monitoring Global Food Security
Yang, W., Kogan, F. N., & Guo, W. F. (2020) · Agronomy · doi:10.3390/agronomy10121936 · Cited by 22 · see citing works
“It is worth emphasizing that the inclination angle of VIIRS on-board satellites have been periodically adjusted to maintain their equator crossing time around the designed value [60], so VIIRS experiences minimal drift.”
BackgroundCalibrating Geosynchronous and Polar Orbiting Satellites: Sharing Best Practices
Helder, D. L., Doelling, D. R., Bhatt, R., Choi, T. J., & Barsi, J. A. (2020) · Remote Sensing · doi:10.3390/rs12172786 · Cited by 10 · see citing works
Vicarious Calibration of the Long Near Infrared Band: Cross-Sensor Differences in Sensitivity
Barnes, B. B., Bailey, S. W., Hu, C., & Franz, B. A. (2022) · IEEE Transactions on Geoscience and Remote Sensing · doi:10.1109/tgrs.2022.3185932 · Cited by 2 · see citing works
- Authors
- Shao, X., Cao, C., Xiong, X., Zhang, B., Uprety, S., & Liu, T.-C.
- Affiliations
- University of Maryland, College Park (US)
- National Oceanic and Atmospheric Administration (US)
- Goddard Space Flight Center (US)
- Earth Resources Technology (United States) (US)
- Venue
- Earth Observing Systems XXIII
- Publisher
- SPIE
- Published
- 2018-09-07
- Pages
- 66
- OpenAlex
- W2892270744
- Cited by
- 4
- References
- 9
- Citations by year
- 2022: 1 · 2020: 3
- FWCI
- 1.30
- Type
- conference paper
- Language
- en
- Open access
- green
- hdl.handle.net
- Locations
- Earth Observing Systems (publishedVersion)
- NASA STI Repository (National Aeronautics and Space Administration) (submittedVersion)
- NOAA Institutional Repository (submittedVersion)
- Funders
- National Oceanic and Atmospheric Administration
- Topics
- Physical Sciences › Engineering › Aerospace Engineering › Calibration and Measurement Techniques
- Physical Sciences › Engineering › Aerospace Engineering › Spacecraft Design and Technology
- Physical Sciences › Environmental Science › Global and Planetary Change › Atmospheric aerosols and clouds
- Keywords
- sun-synchronous satellites, thermal infrared radiometry, MODIS Aqua
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