Showing papers on "Longitude published in 2020"

Three‐dimensional change in temperature sensitivity of northern vegetation phenology

Abstract: Understanding how the temperature sensitivity of phenology changes with three spatial dimensions (altitude, latitude, and longitude) is critical for the prediction of future phenological synchronization. Here we investigate the spatial pattern of temperature sensitivity of spring and autumn phenology with altitude, latitude, and longitude during 1982-2016 across mid- and high-latitude Northern Hemisphere (north of 30°N). We find distinct spatial patterns of temperature sensitivity of spring phenology (hereafter "spring ST ") among altitudinal, latitudinal, and longitudinal gradient. Spring ST decreased with altitude mostly over eastern Europe, whereas the opposite occurs in eastern North America and the north China plain. Spring ST decreased with latitude mainly in the boreal regions of North America, temperate Eurasia, and the arid/semi-arid regions of Central Asia. This distribution may be related to the increased temperature variance, decreased precipitation, and radiation with latitude. Compared to spring ST , the spatial pattern of temperature sensitivity of autumn phenology (hereafter "autumn ST ") is more heterogeneous, only showing a clear spatial pattern of autumn ST along the latitudinal gradient. Our results highlight the three-dimensional view to understand the phenological response to climate change and provide new metrics for evaluating phenological models. Accordingly, establishing a dense, high-quality three-dimensional observation system of phenology data is necessary for enhancing our ability to both predict phenological changes under changing climatic conditions and to facilitate sustainable management of ecosystems.

A (not so) brief history of lunar distances: Lunar longitude determination at sea before the chronometer

Abstract: Longitude determination at sea gained increasing commercial importance in the late Middle Ages, spawned by a commensurate increase in long-distance merchant shipping activity. Prior to the successful development of an accurate marine timepiece in the late-eighteenth century, marine navigators relied predominantly on the Moon for their time and longitude determinations. Lunar eclipses had been used for relative position determinations since Antiquity, but their rare occurrences precludes their routine use as reliable way markers. Measuring lunar distances, using the projected positions on the sky of the Moon and bright reference objects--the Sun or one or more bright stars--became the method of choice. It gained in profile and importance through the British Board of Longitude's endorsement in 1765 of the establishment of a Nautical Almanac. Numerous 'projectors' jumped onto the bandwagon, leading to a proliferation of lunar ephemeris tables. Chronometers became both more affordable and more commonplace by the mid-nineteenth century, signaling the beginning of the end for the lunar distance method as a means to determine one's longitude at sea.

Representation of the equatorial stratopause semiannual oscillation in global atmospheric reanalyses

Abstract: . This paper reports on a project to compare the representation of the semiannual oscillation (SAO) in the equatorial stratosphere and lower mesosphere within six major global atmospheric reanalysis datasets and with recent satellite Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) and Microwave Limb Sounder (MLS) observations. All reanalyses have a good representation of the quasi-biennial oscillation (QBO) in the equatorial lower and middle stratosphere and each displays a clear SAO centered near the stratopause. However, the differences among reanalyses are much more substantial in the SAO region than in the QBO-dominated region. The degree of disagreement among the reanalyses is characterized by the standard deviation (SD) of the monthly mean zonal wind and temperature; this depends on latitude, longitude, height, and time. The zonal wind SD displays a prominent equatorial maximum that increases with height, while the temperature SD reaches a minimum near the Equator and is largest in the polar regions. Along the Equator, the zonal wind SD is smallest around the longitude of Singapore, where consistently high-quality near-equatorial radiosonde observations are available. Interestingly, the near-Singapore minimum in SD is evident to at least ∼3 hPa , i.e., considerably higher than the usual ∼10 hPa ceiling for in situ radiosonde observations. Our measurement of the agreement among the reanalyses shows systematic improvement over the period considered (1980–2016), up to near the stratopause. Characteristics of the SAO at 1 hPa , such as its detailed time variation and the displacement off the Equator of the zonal wind SAO amplitude maximum, differ significantly among the reanalyses. Disagreement among the reanalyses becomes still greater above 1 hPa . One of the reanalyses in our study also has a version produced without assimilating satellite observations, and a comparison of the SAO in these two versions demonstrates the very great importance of satellite-derived temperatures in the realistic analysis of the tropical upper stratospheric circulation.

The role of physical geographic parameters affecting past (1980–2010) and future (2020–2049) thermal stress in Iran

Abstract: In this study, the wet-bulb globe temperature (WBGT) validated biometeorological index is used to monitor and project future human thermal stress in Iran. The meteorological components required to calculate this index include dry and wet temperatures, relative humidity and radiation. To monitor and project thermal stress, data for two time periods are used: (i) baseline data for the period 1980–2010 and (ii) Can-ESM2 model outputs from the CMIP5 model series, which projects values for the period 2020–2049. Four physical geographic factors are used for modeling WBGT frequency; these include station height (elevation), distance from nearest large water body, latitude and longitude. To establish the role of these components on WBGT extreme values, a weighted geographical regression method is used. Findings show that by considering these variables in the form of multivariate weighted regressions, WBGT threshold values are reliably modeled. Based on projected global warming scenarios in coming decades, the threshold of thermal stress occurrence for most regions of Iran shows larger values than those for the reference period. Parameters of latitude, longitude and distance from a large water body will have an incremental impact as contributors to the occurrence of future thermal stress, relative to the reference period. Of these, latitude will have the greatest impact on thermal stress (6.3%), while that for longitude and distance from a large water body will be 2.4% and 1.4%, respectively. However, station elevation will have a reduced impact on thermal stress (by 4.1%).

Moist shallow-water response to tropical forcing: Initial-value problems

Abstract: The response of a spherical moist shallow water system to tropical imbalances in the presence of inhomogeneous saturation fields is examined. While the initial moist response is similar to the dry reference run, albeit with a reduced equivalent depth, the long time solution depends quite strikingly on the nature of the saturation field. For a saturation field that only depends on latitude, specifically, one with a peak at the equator and falls off meridionally in both hemispheres, height imbalances adjust to large-scale, low-frequency westward propagating modes. When the background saturation environment is also allowed to vary with longitude, in addition to a westward quadrupole, there is a distinct eastward propagating response at long times. The nature of this eastward propagating mode is well described by moist potential vorticity conservation and it consists of wave packets that arc out to midlatitudes and return to the tropics and are predominantly rotational in character. In all moist cases, initially formed Kelvin waves decay, and this appears to be tied to the off-equatorial organization of moisture anomalies by rotational modes. Many of these basic features carry over to the response in the presence of realistic saturation fields derived from reanalysis based precipitable water. In boreal summer, long time eastward response is restricted to northern hemisphere and takes the form of a wavetrain that passes over Indian landmass into the subtropics, reaching across the Pacific to North America. In boreal winter, the eastward mode consists of a subtropically confined rotational quadrupole along with midlatitudinal disturbances. Thus, in addition to circumnavigating westward Rossby waves, slow eastward propagating modes appear to be a robust feature of the shallow water system with interactive moisture in the presence of saturation fields that vary with latitude and longitude.

Geographic effects on stable isotopic composition of precipitation across Thailand.

Abstract: This study investigated the spatial variation of isotopes in precipitation over Thailand in relation to geographic condition. Monthly data (2013-2015) of stable isotopes (δ2H and δ18O) in precipitation within the region 5°37'-20°27'N, 98°04'-105°31'E were analysed using the least squares regression method to determine the possible effects of latitude and longitude on δ18O and d-excess in precipitation. Results showed that the spatial variability of isotopes in precipitation is affected by both continental and amount effects and that the variation is slightly greater in terms of latitude than longitude. Latitude and longitude effects both exhibited negative and positive correlations. Negative correlation, whereby isotopic values decreased with increasing latitude, was found during the June-August and September-November periods. Conversely, a positive relationship appeared in the December-February and March-May seasons. These effects had opposite correlation owing to the various moisture sources and different precipitation patterns between seasons. Furthermore, weak correlation for both latitude and longitude effects was revealed during September-November because of the intraseasonal variation of the monsoon. Consequently, the isotopic composition of precipitation in Thailand is controlled not only by geography but also by moisture source and precipitation pattern.

Longitudinal Variations in the Stratosphere of Uranus from the Spitzer Infrared Spectrometer

Abstract: NASA's Spitzer Infrared Spectrometer (IRS) acquired mid-infrared (5–37 μm) disc-averaged spectra of Uranus very near to its equinox in December 2007. A mean spectrum was constructed from observations of multiple central meridian longitudes, spaced equally around the planet, which has provided the opportunity for the most comprehensive globally-averaged characterisation of Uranus' temperature and composition ever obtained (Orton et al., 2014a,b). In this work we analyse the disc-averaged spectra at four separate central meridian longitudes to reveal significant longitudinal variability in thermal emission occurring in Uranus' stratosphere during the 2007 equinox. We detect a variability of up to 15% at wavelengths sensitive to stratospheric methane, ethane and acetylene at the ~0.1-mbar level. The tropospheric hydrogen‑helium continuum and deuterated methane absorption exhibit a negligible variation (less than 2%), constraining the phenomenon to the stratosphere. Building on the forward-modelling analysis of the global average study, we present full optimal estimation inversions (using the NEMESIS retrieval algorithm, Irwin et al., 2008) of the Uranus-2007 spectra at each longitude to distinguish between thermal and compositional variability. We found that the variations can be explained by a temperature change of less than 3 K in the stratosphere. Near-infrared observations from Keck II NIRC2 in December 2007 (Sromovsky et al., 2009; de Pater et al., 2011), and mid-infrared observations from VLT/VISIR in 2009 (Roman et al., 2020), help to localise the potential sources to either large scale uplift or stratospheric wave phenomena.

A Bi-quintic Latitude/Longitude Spline and Lunar Surface Modeling for Spacecraft Navigation

Abstract: A new bi-quintic latitude/longitude spline is developed and applied to the problem of Lunar surface modeling. The new spline provides a singularity-free parameterized function over an oblate spheroid. The bi-quintic spline uses 9 parameters at each of its regular latitude/longitude nodes. At the two poles there are only 6 parameters. The resulting function is continuous and has continuous first and second partial derivatives. Latitude and longitude partial derivatives go to zero at the poles in ways that guarantee continuous first and second partial derivatives of the function when evaluated with respect to Cartesian coordinates as its underlying inputs. The new spline model has been applied to the problem of navigating a Lunar lander. The lander measures slant-ranges to points on the Lunar surface. Its navigation filter uses a model of how the slant-ranges vary with its location and orientation. This model is based on a bi-quintic spline of the Lunar surface, and it returns slant-ranges and their first partial derivatives with respect to spacecraft position and sensor line-of-sight direction. The new sensor model works well in truth-model simulation tests of the navigation filter.

Variations in the Structure of the Equatorial Anomaly during the Summer Solstice according to the Interkosmos-19 Satellite

Abstract: Changes in the structure of the summer equatorial anomaly of electron density with local time and longitude at high solar activity are considered in detail according to topside sounding data from the Interkosmos-19 satellite. It is shown that the equatorial anomaly starts to develop from ~0800 LT, when the winter (southern) crest is formed. The summer (northern) crest is ~2 h behind in development. It is formed at the background of a low latitudinal foF2 maximum. In the daytime, the northern crest is ~3° farther from the geomagnetic equator than the southern one. The crest position changes greatly with longitude. A local maximum is observed in the development of the equatorial anomaly at 1400 LT. It is particularly pronounced in the Eastern Hemisphere. The foF2 value above the geomagnetic equator and anomaly intensity change with longitude at 1200–1400 LT according to the changes in the vertical plasma drift W. A local minimum is observed in the development of the equatorial anomaly at 1800 LT. The anomaly intensity then increases to a maximum 1.5–2.0 h after the evening peak in W. Longitudinal foF2 variations and the anomaly intensity in the interval 2000–2200 LT are also associated with W variations. The anomaly intensity decreases after the maximum, and the crests decrease in magnitude and move toward the equator. The foF2 maxima in the crest region of the anomaly after midnight, conversely, are farther away from the geomagnetic equator, which seems to be due to the action of the neutral wind. The equatorial anomaly has almost decayed by 0400 LT and does not manifest itself as a structure from 0500 to 0700 LT. Therefore, the well-expressed equatorial anomaly is observed from 1200 to 2400 LT at high solar activity.

Random regression of Hereford percentage intramuscular fat on geographical coordinates.

Abstract: Accounting for genotype-environment interactions may improve genetic prediction and parameter estimation. The objective was to use random regression analyses to estimate variances and thereby heritability for intramuscular fat (IMF) across longitude and latitude coordinates within the continental United States. Records from the American Hereford Association (n = 169,440) were used. Analyses were first conducted using the continental United States in its entirety, and then as subdivided into two or four regions. Data were analyzed with an animal model, and linear and quadratic random regressions of additive genetic merit on longitude or latitude as covariate (separately). Subdivided data were analyzed with linear random regressions unique to regions. Regions were North and South separated at 40°N latitude, or West and East separated at 99°W longitude using longitude or latitude as covariate, respectively. Further subdivision to four regions included additional boundaries of 44.46° and 36.46°N latitude and 104.55° and 92.22°W longitude. The estimated heritability of IMF from the traditional model was 0.19 ± 0.004. Without regional subdivision of data, quadratic random regression had the best fit for the data based on likelihood ratio tests using longitude or latitude as covariate (P < 0.01). Estimates of heritability from quadratic random regression on latitude ranged from 0.12 in the South to a high of 0.27 at the extreme Northern latitude. Estimates of heritability from quadratic random regression on longitude ranged from 0.17 in the middle of the parameter space (corresponding to the central United States) to 0.37; higher estimates were noted at the extremes, that is, the far West and East longitudes. Random regression analyses of data divided into regions were conducted with a linear coefficient, as increasing to a quadratic polynomial was never accomplished. Results from random regression on latitude in the East region were similar to results from analyses without regions (h2 ranged from 0.09 to 0.32); however, estimates of heritability in the West region had a lower range from South to North (0.14 to 0.27). Estimates of heritability from random regression on longitude with data divided into two regions were similar to those from analyses that did not include region. Estimates in the South region were somewhat lower and had a lower range (0.15 to 0.31) than those from the North region (0.19 to 0.47). When data were further subdivided, estimation of only a subset of covariances among random regression coefficients was possible, that is, within-region covariances of intercept and linear terms (latitude); those and covariances between all linear random regression coefficients were estimated when longitude was the covariate. Results from random regression analyses of data with four regions modeled produced very high estimates of heritability in low latitudes in the furthest West and high latitudes in the furthest East region, with approximate difference of 0.3 and 0.2 between estimates in the two West regions and the two East regions, respectively. Results from random regression on longitude indicated higher estimates of heritability in North region, especially at the furthest East longitudes of the most Northern region. There appeared to be substantial additive genetic variance differences, as well as estimates of heritability, that correspond to different geographical environments as modeled by random regressions on within-region latitude or longitude coordinates.

A (not so) brief history of lunar distances: lunar longitude determination at sea before the chronometer

Abstract: Longitude determination at sea gained increasing commercial importance in the late Middle Ages, spawned by a commensurate increase in long-distance merchant shipping activity. Prior to the successful development of an accurate marine timepiece in the late-eighteenth century, marine navigators relied predominantly on the Moon for their time and longitude determinations. Lunar eclipses had been used for relative position determinations since Antiquity, but their rare occurrences precludes their routine use as reliable way markers. Measuring lunar distances, using the projected positions on the sky of the Moon and bright reference objects--the Sun or one or more bright stars--became the method of choice. It gained in profile and importance through the British Board of Longitude's endorsement in 1765 of the establishment of a Nautical Almanac. Numerous 'projectors' jumped onto the bandwagon, leading to a proliferation of lunar ephemeris tables. Chronometers became both more affordable and more commonplace by the mid-nineteenth century, signaling the beginning of the end for the lunar distance method as a means to determine one's longitude at sea.

Flat Model for Representing Contiguous UTM Coordinates over Iraq Territory

Abstract: The process of converting coordinates is, still, considered an important and difficult issue due to the way of conversion from geographic ellipsoidal system to the projected flat system. The most common method uses contiguous UTM system as one of the most accurate systems in the conversion process, but the users of thesystem face problems related to contiguity, especially at the large areas that lie within more than one zone. The aim of the present research is to solve the problem related to the multiple zones coverage found in the Iraqi territory using a mathematical model based on the use of Taylor series. The most accurate conversion equation used in this paper was based on the 4th order polynomial of two variables. The calculation of equations’ coefficients was performed using least square criterion for the coordinate’s values, i.e., either latitude, longitude) or East (E), North (N) coordinates. The two basic determinations, for the forward and backward, wereapplied. In the first stages, the conversion of the coordinates from Longitude/ Latitude to East/ North was determined. Then, the second conversion stage was determined, i.e., the coordinates conversion from East, North to Longitude, Latitude). For each phase, a spatial accuracy assessment was conducted. The resultsshowed that the adopted mathematical model was successful to accomplish the conversion process. A very small error average of about 3 cm at east and less than 5 cm at north was reached using the 4th order polynomial equations.

Paper map rapid vectorization method and system based on longitude and latitude recognition

Abstract: The invention discloses a paper map fast vectorization method and system based on longitude and latitude recognition. The paper map fast vectorization method comprises the steps: S100, performing deviation rectification on a grid image; S200, performing geometric constraint on the corrected raster image, and extracting a longitude to-be-matched region and a latitude to-be-matched region; S300, reading longitude and latitude template images corresponding to the grid images, and matching the longitude and latitude template images with areas to be matched of longitude and latitude; S400, solvingsix parameters of the affine transformation model by utilizing the central point pixel horizontal/vertical coordinates and longitude/latitude values obtained by matching; S500, carrying out color space transformation on the grid image after deviation rectification; and S600, performing vectorization processing on the grid image output in the step S500, and converting pixel points into geographic coordinates one by one. By means of the modern computer technology, rapid and automatic vectorization of a raster image obtained after scanning of a paper map is achieved, and meanwhile accurate conversion from pixel coordinates to geographic coordinates is achieved.

BEC SMOS Sea Surface Salinity global L4 product (V.2.0) [Dataset]

Abstract: Data acquisition Satellite: ESA SMOS mission (Soil Moisture and Ocean Salinity). Time coverage: 1 January, 2011 31 December, 2019. Time resolution 1 day. Maps frequency generation: Daily.- Spatial coverage. Latitude range: 90oS-90oN Longitude range: 180oW-180oE. Spatial resolution: 0.05ox0.05o. Spatial projectionWGS 84: Latitude-longitude projection WGS84. Spatial grid: Latitude and longitude regular grid at 0.05 degrees. Sensor: Satellite SMOS / MIRAS. Source product: SMOS Level 1B (brightness temperature Fourier coefficients) v 621 provided by ESA. Format NetCDF Climate and Forecast (CF) Metadata Conventions version 1.6. Size 303 Gb

Towards Single Value Coordinate System (SVCS) for Earthquake Forecasting Using Single Layer Hierarchical Graph Neuron (SLHGN).

Abstract: The current coordinate system has been the major challenge for the development of earthquake forecasting technology using Single Layer Hierarchical Graph Neuron (SLHGN). First, the accuracy of the longitude value is not distributed equally, and the accuracy gets worse towards the poles. Second, the distance of the same longitude difference varies following the difference of the latitude values. The extreme one is again on the poles, where the longitude value becomes unity. Third, there is no way to have a coordinate of an area. As an alternative the Single Value Coordinate System (SVCS) has been scrutinized and elaborated. The coordinate system treats every area on the earth equally on the equator until the poles. It means that the accuracy is everywhere the same and the calculation of a distance and an area is not dependent on the location (e.g. near the equator, near the North Pole, etc.). At this stage the algorithm for measuring a distance and the conversion from and to the current coordinate system are available. The distance between two locations is directly discovered from the value of the coordinate itself. The coordinate system is fundamentally dedicated to pinpoint an area, not a point. The smaller an area is the more precise the location will be. Using the SVCS, the characteristic of the earth as a spherical shape suits the SLHGN architecture.

Longitude 45° East: New Evidence for one of the Oldest Political Frontiers in the Ancient World

Abstract: The Zagros mountains, which constitute the defining topographic divider between Iraq and Iran, have over the course of history been witness to countless incursions and invasions launched from Mesopotamia into Iran and vice-versa. The rock reliefs, stelae, and kudurrus discovered in the western foothills of this mountain range indicate that throughout history the region witnessed many major events and conflicts, with numerous monuments being erected to commemorate victories (see Fig. 1). In this context, this study focuses on two new rock reliefs discovered in late February 2019 on the southernmost part of Bamu mountain, overlooking the bank of the Hawasan river—monuments probably

Determining the parameters of a local coordinate system with a non-standard longitude of the central meridian. Analysis of existing methods

Abstract: Processing the results of topographic and geodetic works is performed in local coordinate systems. The parameters of the local coordinate systems were established on the basis of SK-42 or SK-63 systems. At present, it is necessary to set new communication parameters with coordinate systems SK-95 and GSK-2011. In many MCSs, the central meridians do not coincide with the origin, and the coordinates of the starting points were obtained from the catalogs of the preliminary calculation geodetic network. To establish the new communication parameters, it is necessary to determine the longitude of the central meridian MCS in SK-95 and GSK-2011 systems. To find the errors in calculating the longitude of the central meridian, MCS the models were constructed with different positions of the central meridian relative to the origin. The longitude was calculated using well-known and new formulas and methods. Errors in calculating the longitude of the MSC are systematic. An increase in the calculation volume does not exclude the influence of systematic errors, reaching 4ʺ. For some lines, they make 8ʺ.

Autonomous Determination of Vehicle Longitude

Abstract: Paper deals with an algorithm for obtaining the vehicle’s longitude. Methods of full autonomous determination of initial positioning are represented. The process describes the longitude determining designed on the initial latitude obtaining. The strap-down inertial technology is used for initial latitude determination. The inertial measurement unit should be consisted of a set of gyroscopes and accelerometers. The longitude determination is described for both ways of moving base - orthodromic and loxodromic movements. The error of longitude determination is derived. It is shown that the error model depends on azimuth and latitude errors.

Interhemispheric conjugate effect in longitude variations of mid-latitude ion density

Abstract: Earlier incoherent scatter radar measurements revealed upward topside ion fluxes in the summer and downward fluxes in the winter at mid-latitudes at night; a summer to winter interhemispheric coupling was accordingly inferred. However, this interhemispheric coupling through the plasmasphere is difficult to confirm directly from observations. A possible result induced by this coupling is interhemispheric conjugacy of the mid-latitude ionosphere. In this paper, interhemispheric conjugate effect in longitude variations of mid-latitude total ion density (N i ) is presented, for the first time, using the Defense Meteorological Satellite Program (DMSP) measurements; northern and southern N i longitude variations at 21:30 LT are similar between magnetically conjugate mid-latitudes around solar minimum June Solstice of 1996. The conjugate effect after sunset also occurs around the June Solstice in other solar minimum years but disappears when solar activity increases. We suggested that mid-latitude interhemispheric coupling is responsible for the conjugate effect. Neutral wind induced ionospheric transport causes topside longitude variations via upward diffusion at summer mid-latitudes; this further induces similar longitude variations of topside N i at winter mid-latitudes via the summer to winter interhemispheric coupling. The conjugate effect occurs only inside the plasmapause where magnetic flux tubes are closed and the plasma in these tubes can stably corotate with the Earth. The conjugate effect not only proves mid-latitude interhemispheric coupling through the plasmasphere, but also implies that neutral wind induced transport can affect ionospheric coupling to the plasmasphere at mid-latitudes.

Storm time PP fields effects and TADs modulations in TEC

Abstract: The latitudinal response to the geomagnetic storm of 15 May 2005 has been examined over the chain of stations extending from the equatorial region to the mid-latitude along the Indian longitude sector. Based upon the TEC observations, it has been settled that the response of the ionosphere to the storm time prompt penetration (PP) fields has latitudinal dependence, although the PP fields infiltrate near-simultaneously from mid to equatorial latitudes. Effect of storm-induced meridional winds on TEC has also been perceived along with modulations in TEC manifested by traveling atmospheric disturbances (TADs).

Method, device and system for intelligent terminal to obtain weather information

Abstract: The invention discloses a method, device and system for an intelligent terminal to obtain weather information, and the method comprises the following steps: S1, determining the longitude and latitudeof the intelligent terminal at intervals of a preset time period, executing S2 according to this longitude and latitude if the longitude and latitude are determined successfully, and executing S2 according to the longitude and latitude determined successfully before if the longitude and latitude are not determined successfully; S2, determining an area corresponding to longitude and latitude; S3, sending the longitude and latitude and the corresponding area to a server; and S4, receiving the weather information sent by the server. Based on the position of the intelligent terminal and the area information, the weather information is actively updated in real time according to the position of the intelligent terminal, a user can check the weather information and the weather early warning information of the area where the user is located at any time, user experience is improved, and the user can conveniently obtain the weather information in real time. Positioning is carried out once at setintervals, so that resource waste caused by frequent refreshing can be avoided.

Method and apparatus for compressing and decompressing positioning information

Abstract: Provided are a method and apparatus for compressing and decompressing positioning information. The method comprises: when the acquired latitude coordinate of a terminal is greater than a critical coordinate of a high-latitude area, respectively determining a target high-latitude area to which the latitude coordinate belongs, target data occupancy bits corresponding to the target high-latitude area, and a target coordinate conversion rule; then, according to the target coordinate conversion rule, converting longitude integer information into data on the occupied bits of the longitude integer information, and converting longitude minute and second information into data on the occupied bits of the longitude minute and second information, so as to obtain first compressed data; and sending the first compressed data to a base station. It can be seen that when the latitude coordinate of a terminal belongs to a high-latitude area coordinate, integer information of the longitude coordinate is converted and compressed together with longitude minute and second information according to the corresponding target coordinate conversion rule, and is sent to a base station for reduction, thereby solving the problem of longitude coordinate distortion in the high-latitude area, and ensuring the reduction accuracy of the compressed positioning information.