Multitarget tracking and terrain-aided navigation using square-root consider filters

Filtering is a term used to describe methods that estimate the values of partially observed states, such as the position, velocity, and attitude of a vehicle, using current observations that are corrupted due to various sources, such as measurement noise, transmission dropouts, and spurious information. The study of filtering has been an active focus of research for decades, and the resulting filters have been the cornerstone of many of humankind\u27s greatest technological achievements. However, these achievements are enabled principally by the use of specialized techniques that seek to, in some way, combat the negative impacts that processor roundoff and truncation error have on filtering. Two of these specialized techniques are known as square-root filters and consider filters. The former alleviates the fragility induced from estimating error covariance matrices by, instead, managing a factorized representation of that matrix, known as a square-root factor. The latter chooses to account for the statistical impacts a troublesome system parameter has on the overall state estimate without directly estimating it, and the result is a substantial reduction in numerical sensitivity to errors in that parameter. While both of these techniques have found widespread use in practical application, they have never been unified in a common square-root consider framework. Furthermore, consider filters are historically rooted to standard, vector-valued estimation techniques, and they have yet to be generalized to the emerging, set-valued estimation tools for multitarget tracking. In this dissertation, formulae for the square-root consider filter are derived, and the result is extended to finite set statistics-based multitarget tracking tools. These results are used to propose a terrain-aided navigation concept wherein data regarding a vehicle\u27s environment is used to improve its state estimate, and square-root consider techniques provide the numerical stability necessary for an onboard navigation application. The newly developed square-root consider techniques are shown to be much more stable than standard formulations, and the terrain-aided navigation concept is applied to a lunar landing scenario to illustrate its applicability to navigating in challenging environments --Abstract, page iii

Segmented Aperture Interferometric Nulling Testbed (SAINT) II: Component Systems Update

"This work presents updates to the coronagraph and telescope components of the Segmented Aperture Interfer-ometric Nulling Testbed (SAINT). The project pairs an actively-controlled macro-scale segmented mirror withthe Visible Nulling Coronagraph (VNC) towards demonstrating capabilities for the future space observatoriesneeded to directly detect and characterize a significant sample of Earth-sized worlds around nearby stars inthe quest for identifying those which may be habitable and possibly harbor life. Efforts to improve the VNCwavefront control optics and mechanisms towards repeating narrowband results are described. A narrative isprovided for the design of new optical components aimed at enabling broadband performance. Initial work withthe hardware and software interface for controlling the segmented telescope mirror is also presented.

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Early Detection and Monitoring of Cancer with the Anti-Malignin Antibody Test "

ABSTRACT: The serum anti-malignin antibody (AMA) test determines the antibody to malignin. a IO,OOO-Da peptide present in patients with a wide variety of cancers.l~ A total of 3315 double-blind tests demonstrated that AMA is a general transformation antibody, elevated in active no.nterminal cancer, regardless of the site or tissue type, with sensitivity and specificity of95% on the flTst determination and >99% on repeat determinations. - 9 Data have not however been published yet that indicate whether, in daily clinical practice, the AMA test provides accurate prospective and predictive information. Fony-two physicians from II states, who ordered the AMA test, performed blind, report here on their results on 208 determinations in the first consecutive 181 patients and controls. Used in monitoring treatment in 56 patients, the test predicted or agreed 94.1 % overall with the clinical status. Used in early detection in 125 patients and controls, of which 118 now have confirmed diagnoses. AMA was elevated in 21, all of whom were proven to have cancer; AMA was normal in 97, none of whom had cancer. Transient elevated AMA occurred in 3%, followed by normal values. Seven patients with still uncertain diagnosis who have had elevated AMA on repeated tests for I year or longer include six who are symptomatic, and three whose families have a high frequency of cancer. The conditions of these 7 may include undetected cancer because of the 118 with now certain diagnosis the AMA test predicted all correctly. From our experience, the AMA test should be used together with other routine procedures whenever signs and symptoms suggest cancer to facilitate early detection

State of the climate in 2018

In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and$6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)

Psychometric properties of the Mandarin version of the Childhood Autism Spectrum Test (CAST):an exploratory study

Limited studies have investigated the latent autistic traits in the mainland Chinese population for autism spectrum conditions (ASC). This study explored the psychometric properties of a Mandarin Chinese version of the CAST in a sample consisting of 737 children in mainstream schools and 50 autistic cases. A combination of categorical data factor analysis and item response theory suggested a good-fit model of a two-factor solution for 28 items on the Mandarin CAST including social and communication, and inflexible/stereotyped language and behaviours (Goodness-of-fit indices: RMSEA = 0.029, CFI = 0.957, TLI = 0.950, SRMR = 0.064). The correlation between the two factors was moderate (GFC = 0.425). This study provided evidence for the CAST as a multidimensional measure for ASC screening in a Chinese population and also showed that the symptom manifestation of ASC in Chinese children shares similarity with western populations. © 2014 Springer Science+Business Media

Development and Flight of a Stereoscopic Imager for Use in Spacecraft Close Proximity Operations

Proximity operations about noncooperative resident space objects (RSOs) is a current area of research with the intent to enable many useful on-orbit missions. One method of performing passive proximity operations about a noncooperative RSO uses two cameras to obtain stereo line-of-sight data to the RSO in order to fully resolve the relative position and velocity of the RSO and navigate about it. An overview of the MR and MRS SAT mission, in which a stereoscopic imager is used aboard MR SAT to navigate about MRS SAT (a mock noncooperative RSO) is presented. The developed hardware and algorithms used by the stereoscopic imaging sensor, as well as the guidance, navigation, and control subsystems, are presented. A software-in-the-loop simulation is presented to demonstrate the expected on-orbit performance of the MR and MRS SAT mission

Successful and unsuccessful recruitment and retainment strategies in a UK multicentre drug trial for a rare chronic pain condition which performed above target

Introduction: Recruitment into trials in rare chronic pain conditions can be challenging, so such trials consequently are underpowered or fail. Methods: Drawing from our experience in conducting, to date, the largest academic trial in a rare chronic pain condition, complex regional pain syndrome, we have identified recruitment and retention strategies for successful trial conduct. Results: We present 13 strategies grouped across the categories of ‘setting the recruitment rate’, ‘networking’, ‘patient information’, ‘trial management’ and ‘patient retention’. Moreover, six recruitment risks are also discussed. A conservative recruitment estimate, based on audits of newly referred patients to the trial centres without taking into account availability of ‘old’ patients or recruitment from outside centres, and assuming a 55% patient refusal rate yielded accurate numbers. Conclusion: Appreciation of these identified recruitment challenges and opportunities may contribute to supporting prospective investigators when they design clinical trials for chronic pain patient population groups where it has been historically difficult to conduct high-quality and robust clinical trials