There is a problem w/ your write-up. Check that you have valied entries for \$CAID and \$Campn in your analysis.php file. If that checks out, then Contact Stansberry"; return ; } // get first matching task $row = mysql_fetch_array($result); $title = $row["title"]; $princ = $row["principal"]; $deputy= $row["deputy"]; $campn0 = $row["campn0"]; $aorkeys = $row["aorkeys"]; // get real name of principal, deputies $princ = ioc_get_person($princ); $princ = $princ[0]; $deps = explode(",",$deputy); foreach ($deps as $depty) { $depty = trim($depty); $depty = ioc_get_person($depty); $depty = $depty[0]; $depty = explode(",",$depty); $depty = $depty[0]; // last names only $deplist[] = $depty; } $deplist = implode(", ", $deplist); $caid = sprintf("%03d",$caid); $file = "mips-".$caid.$campn.".analysis.php"; // if more matches, append the AORKEYS from those $numrows = mysql_num_rows($result); if ($numrows > 1) { $aorkeys = " " . $numrows . " Task Executions:  ". $aorkeys; for ($i=0;$i < mysql_num_rows($result); $i++) { $row = mysql_fetch_array($result); $morekeys = $row["aorkeys"]; $aorkeys = $aorkeys .';  '.$morekeys; } } // END PHP. ?> <? echo "MIPS-$caid, Campaign $campn IOC/SV Analysis"; ?>

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Task Outcome Summary


Abstract

Observations corresponding to 30%, 100%, and 300% of full well were taken. These saturation levels will be achieved through a combination of source selection and exposure times. At each of the three signal levels: (1) Observe a source using a small field dither pattern (1 cycle); (2) Execute a flush cycle (dark sky observation) to elimate latents from the next set of exposures. The results show that latents do not persist strongly beyond the first DCE after an exposure is taken (as seen in ground test). Unfortunately, the 24um small field AOT used in this task is unsuitable for tracking the detailed time history of latents since the second DCE following a given exposure places the latent within the first Airy ring of the new image. This design may have negative implications for photometry of bright sources.

Analysis

This task was accomplished entirely with AORs. We pointed at HD152222 and obtained a single cycle of 24 µm small field photometry (16 DCEs) with 3 sec exposures (~30% full well). Then we moved to a dark sky region 1 deg N & E of HD152222 and performed 3 sec single photometry cycles at two positions offset by 10" to allow any bright object latents to disappear. We returned to HD152222 for 10 sec exposures, followed by cycles of 3 sec exposures on dark sky to flush the latents. Finally, we observed HD152222 with 30 sec exposures to obtain 300% full well stellar images. Following the observations, the data were reduced using DAT v2.20. Calibration files from Campaign F were utilized in the reduction. The intent was to measure latent image photometry using tools in IRAF. The following figure shows the latent images remaining after a 10 second exposure on a point source close to saturation (left side of image; latent is faint source well above star):


Unfortunately, the design of the 24um small field photometry places the images in every other DCE too close together for tracking the time history of latents. In the second DCE after an exposure, its latent falls within the first Airy ring of the current exposure. This effect, illustrated in Figure 2, causes the current data set to be unsuitable for tracking latents. The figure shows the position of the potential latent from two DCEs in the past (green x) relative to the stellar image.



Results

In a 3 second exposure with a source ~30% of full well, the latent in the first DCE has a value of 0.8% of the original image In a 10 second exposure with a source ~100% of A-to-D saturation, the latent in the first DCE has a value of 0.66% of the original image. In a 30 second exposure with a source ~300% of A-to-D saturation, the latent in the first DCE has a value of 0.68% of the original image. Further analysis of other data sets is required to trace the detailed time history of latents on the 24um array.

Conclusions

For Si:As temperature = 5.2 K, latent images should not be a serious problem for unsaturated and mildly saturated sources. The latent in the first DCE after the exposure is less than 1% of the original source. However, since latents may appear within the first Airy ring of subsequent images in 24um small field photometry, we should consider separating the images more widely through CSMM parameter manipulation to avoid contamination of photometry.

Output and Deliverable Products

None

Actions Following Analysis

Analyze the focus and FPS IERs to track the time history of latents at 24um. Replace the MIPS-155 AORs in Campaign R with an IER which will allow the latents at the final array temperature to be tracked. If the team decides to change the 24um small field AOT, implement a new set of CSMM parameters to more widely distribute the images.