Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 197
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 197
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 271
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3165
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 597
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 511
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 317
Function: require_once
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Satellite Laser Ranging (SLR) is a well established space geodetic technique measuring the satellite distance, which implements time of flight. Up to now, second harmonic Nd:YAG laser pulses have been frequently used for range measurement, since the silicon detector technology allows us to detect single photon echoes reflected from satellites with required high detection probability, millimeter precision, and an acceptable dark count rate. On the other hand, the fundamental wavelength (1064 nm) provides a significantly better overall energy budget, but there were no suitable detectors available. More recently, the use of InGaAs/InP became feasible for developing single photon avalanche diodes, which exhibit high photon detection probability and acceptable timing resolution. Both these properties are important and allow the SLR measurement at the fundamental wavelength. In this Note, we report on construction and testing of a single photon detector package based on the InGaAs/InP diode optimized for the SLR measurement.
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http://dx.doi.org/10.1063/5.0006516 | DOI Listing |