17358( 2) - 06-Jul-2023 20:02:46 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17358 Version: 2 Check-in Time: 06-Jul-2023 20:02:46 STScI Edit Number: 0 Title WFC3 IR Linearity Monitor ------------------------------------------------------------------------------------ Type Cycle CAL/WFC3 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Joel David Green Space Telescope Science Institute Y CoI: Varun Bajaj Space Telescope Science Institute Y ------------------------------------------------------------------------------------ Abstract The WFC3/IR detector exhibits a non-linear response to incident flux. The data reduction pipeline provides a correction for the non-linearity, which depends on accurate characterization of the response of the detector. To monitor the non-linearity of the WFC3/IR detector, we use a dark observation followed by two internal flats using the Tungsten lamp at different sampling rates, and a trailing dark. Any changes measured in the non-linearity will be updated in the calibration reference file, crucial to providing a correction for accurate photometry. This program is a continuation of the cycle 30 (program 17012) linearity calibration program ------------------------------------------------------------------------------------ Observations Description ------------------------ To monitor the non-linearity of the WFC3/IR detector, we use a dark observation followed by two internal flats using the Tungsten lamp. We begin with a narrow band flat to ensure that the lamp is warm and stable, but not so bright as to cause persistence, observing the Tungsten lamp with F126N (half SPARS10 and half SPARS50). Then we take internal flats though the F127M filter at different signal levels and sampling sequence (half SPARS10 and half SPARS25). After the F127M flat, a dark is obtained to measure the persistence decay rate. ------------------------------------------------------------------------------------ 17358( 2) - 06-Jul-2023 20:02:46 - [ 2] Visit: 01 (SPARS25a) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 3] Visit: 02 (SPARS25b) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 4] Visit: 03 (SPARS25c) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 5] Visit: 04 (SPARS25d) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 6] Visit: 05 (SPARS25e) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 7] Visit: 06 (SPARS25f) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=11 1 DEF CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS10, NSAMP=6 1 DEF CUM (52.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 8] Visit: 07 (SPARS10a) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS100, NSAMP=3 1 DEF CUM (202.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS50, NSAMP=2 1 DEF CUM (52.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS10, NSAMP=15 1 DEF CUM (142.946 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 9] Visit: 08 (SPARS10b) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS100, NSAMP=3 1 DEF CUM (202.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS50, NSAMP=2 1 DEF CUM (52.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS10, NSAMP=15 1 DEF CUM (142.946 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 10] Visit: 09 (SPARS10c) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS100, NSAMP=3 1 DEF CUM (202.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS50, NSAMP=2 1 DEF CUM (52.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS10, NSAMP=15 1 DEF CUM (142.946 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 11] Visit: 10 (SPARS10d) Visit Requirements: BEFORE 01-FEB-2024:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS100, NSAMP=3 1 DEF CUM (202.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN WFC3/IR MULTIAC IR F126N SAMP-SEQ=SPARS50, NSAMP=2 1 DEF CUM (52.933 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TUNGSTEN WFC3/IR MULTIAC IR F127M SAMP-SEQ=SPARS10, NSAMP=15 1 DEF CUM (142.946 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DARK WFC3/IR MULTIAC IR BLANK SAMP-SEQ=SPARS25, NSAMP=15 1 DEF CUM (352.94 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM TUNGSTEN 2 WFC3/IR MULTIAC IR F126N none none none none 1 N/A CUM TUNGSTEN 3 WFC3/IR MULTIAC IR F127M none none none none 1 N/A CUM DARK 4 WFC3/IR MULTIAC IR BLANK none none none none 1 N/A CUM 17358( 2) - 06-Jul-2023 20:02:46 - [ 12] Summary Form for Proposal 17358 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=11, NSAMP=15, NSAMP=2, NSAMP=3, NSAMP=6, SAMP-SEQ=SPARS10, SAMP-SEQ=SPARS100, SAMP-SEQ=SPARS25, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 01-FEB-2024:00:00:00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements BLANK, F126N, F127M ------------------------------------------------------------------------------------------------------------------------------------ Target Names DARK, TUNGSTEN ------------------------------------------------------------------------------------------------------------------------------------